WorldWideScience

Sample records for path sampling throwing

  1. Throwing accuracy

    Science.gov (United States)

    Cross, Rod

    2018-05-01

    A simple throwing task is described to illustrate various aspects of projectile motion. The task was to throw a tennis ball in a waste paper bin about 2 m away. Success depends on skill, but it also depends on the physics of the problem. If the ball is thrown underarm, then success depends primarily on the throw speed, which must be controlled to within about 2%. The launch angle can be chosen within a wide range. If the ball is thrown overarm, then the launch angle is just as important as the throw speed.

  2. Nonadiabatic transition path sampling

    International Nuclear Information System (INIS)

    Sherman, M. C.; Corcelli, S. A.

    2016-01-01

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

  3. Influence of the throwing direction on biomechanics of movement patterns in handball throws

    Directory of Open Access Journals (Sweden)

    Marcos Gutiérrez-Dávila

    2013-07-01

    Full Text Available The purpose of this study was to compare players’ intra-individual variability in the movement pattern of four throwing directions, which were realized to one of the corners of the goal, in presence of the goalkeeper in handball. Five players participated at the first division of Spanish Handball. Each thrower completed 35 throws in different directions. 3D video techniques were used to determine the rectangular components of the spacial positions between 5 body markers and the ball. An analysis of variance was used to detect the changes produced by the direction of the throw. An additional analysis of variance was used to measure the temporary differences of the direction of the throw using the positions of the 5 body markers used by the 3 specialist throwers. The data showed that when the throw was directed to the left side, the time for the throw was significally longer, and when the throw was directed to lower zones, the time of release tended to increase even more, because the ball is released higher.

  4. The Throws: Contemporary Theory, Technique and Training.

    Science.gov (United States)

    Wilt, Fred, Ed.

    This compilation of articles covers the subject of four throwing events--shot put, discus throw, hammer throw, and javelin throw. The history of the art and science of throwing is traced from ancient to modern times in the introduction. Theories on training and techniques of throwing are presented in essays contributed by coaches from the United…

  5. Sport-Specific Training Targeting the Proximal Segments and Throwing Velocity in Collegiate Throwing Athletes

    Science.gov (United States)

    Palmer, Thomas; Uhl, Timothy L.; Howell, Dana; Hewett, Timothy E.; Viele, Kert; Mattacola, Carl G.

    2015-01-01

    Context The ability to generate, absorb, and transmit forces through the proximal segments of the pelvis, spine, and trunk has been proposed to influence sport performance, yet traditional training techniques targeting the proximal segments have had limited success improving sport-specific performance. Objective To investigate the effects of a traditional endurance-training program and a sport-specific power-training program targeting the muscles that support the proximal segments and throwing velocity. Design Randomized controlled clinical trial. Setting University research laboratory and gymnasium. Patients or Other Participants A total of 46 (age = 20 ± 1.3 years, height = 175.7 ± 8.7 cm) healthy National Collegiate Athletic Association Division III female softball (n = 17) and male baseball (n = 29) players. Intervention(s) Blocked stratification for sex and position was used to randomly assign participants to 1 of 2 training groups for 7 weeks: a traditional endurance-training group (ET group; n = 21) or a power-stability–training group (PS group; n = 25). Mean Outcome Measure(s) The change score in peak throwing velocity (km/h) normalized for body weight (BW; kilograms) and change score in tests that challenge the muscles of the proximal segments normalized for BW (kilograms). We used 2-tailed independent-samples t tests to compare differences between the change scores. Results The peak throwing velocity (ET group = 0.01 ± 0.1 km/h/kg of BW, PS group = 0.08 ± 0.03 km/h/kg of BW; P < .001) and muscle power outputs for the chop (ET group = 0.22 ± 0.91 W/kg of BW, PS group = 1.3 ± 0.91 W/kg of BW; P < .001) and lift (ET group = 0.59 ± 0.67 W/kg of BW, PS group = 1.4 ± 0.87 W/kg of BW; P < .001) tests were higher at postintervention in the PT than in the ET group. Conclusions An improvement in throwing velocity occurred simultaneously with measures of muscular endurance and power after a sport-specific training regimen targeting the proximal segments

  6. Where Are You Throwing the Ball? I Better Watch Your Body, Not Just Your Arm!

    Directory of Open Access Journals (Sweden)

    Antonella Maselli

    2017-10-01

    Full Text Available The ability to intercept or avoid a moving object, whether to catch a ball, snatch one’s prey, or avoid the path of a predator, is a skill that has been acquired throughout evolution by many species in the animal kingdom. This requires processing early visual cues in order to program anticipatory motor responses tuned to the forthcoming event. Here, we explore the nature of the early kinematics cues that could inform an observer about the future direction of a ball projected with an unconstrained overarm throw. Our goal was to pinpoint the body segments that, throughout the temporal course of the throwing action, could provide key cues for accurately predicting the side of the outgoing ball. We recorded whole-body kinematics from twenty non-expert participants performing unconstrained overarm throws at four different targets placed on a vertical plane at 6 m distance. In order to characterize the spatiotemporal structure of the information embedded in the kinematics of the throwing action about the outgoing ball direction, we introduced a novel combination of dimensionality reduction and machine learning techniques. The recorded kinematics clearly shows that throwing styles differed considerably across individuals, with corresponding inter-individual differences in the spatio-temporal structure of the thrower predictability. We found that for most participants it is possible to predict the region where the ball hit the target plane, with an accuracy above 80%, as early as 400–500 ms before ball release. Interestingly, the body parts that provided the most informative cues about the action outcome varied with the throwing style and during the time course of the throwing action. Not surprisingly, at the very end of the action, the throwing arm is the most informative body segment. However, cues allowing for predictions to be made earlier than 200 ms before release are typically associated to other body parts, such as the lower limbs and the

  7. External Versus Two Different Internal Foci of Attention in Long-Distance Throwing.

    Science.gov (United States)

    Oki, Yuta; Kokubu, Masahiro; Nakagomi, Shiro

    2018-02-01

    The present study examined the influence of attentional focus on performance during a long-distance throwing task. Twelve participants executed three maximum-effort, long-distance baseball throwing attempts in three focus conditions: internal focus on wrist flexion (wrist internal focus), internal focus on the separation between pelvis and upper torso orientations (torso internal focus), and external focus on the ball path (external focus). Compared with the external focus and torso internal focus conditions, performance was poorer in the wrist internal focus condition. Performances were not different in the torso internal and external focus conditions. In addition, attentional focus affected the release angle of the ball but not its initial velocity. Our results reveal that the body part targeted for internal focus of attention and the forcefulness of the motor activity can be as important to motor performance as whether the attention is internal or external.

  8. CONNECTION OF FUNCTIONAL ABILITIES WITH JUMPING AND THROWING ATHLETIC DISCIPLINES

    Directory of Open Access Journals (Sweden)

    Igor Stanojević

    2014-06-01

    Full Text Available The aim of this study was to determine the connection between functional abilities with results of jumping and throwing athletic disciplines with athletes. The sample was taken from a population of elementary school students from Prokuplje region, 13 and 14 old, included in regular physical education classes. The sample consisted of 200 male athletes involved in the training process in sports clubs at least three times a week in addition to physical education classes. For assessment of functional abilities six functional tests were used: resting heart rate, Cooper test, heart rate in the first minute after Cooper test, heart rate in the second minute after Cooper test, systolic arterial blood pressure, diastolic arterial blood pressure. For assessment of jumping and throwing athletic disciplines four tests were used: long jump, high jump, shot put and javelin. Data analysis was performed with canonical correlation and regression analysis. The results showed a statistically significant correlation between functional abilities with all of tests in jumping and throwing athletic disciplines.

  9. The physics of an optimal basketball free throw

    OpenAIRE

    Barzykina, Irina

    2017-01-01

    A physical model is developed, which suggests a pathway to determining the optimal release conditions for a basketball free throw. Theoretical framework is supported by Monte Carlo simulations and a series of free throws performed and analysed at Southbank International School. The model defines a smile-shaped success region in angle-velocity space where a free throw will score. A formula for the minimum throwing angle is derived analytically. The optimal throwing conditions are determined nu...

  10. Snowball Throwing in Teaching Grammar

    Directory of Open Access Journals (Sweden)

    Yanuarti Apsari

    2018-05-01

    Full Text Available The aims of this study are to describe the implementation of snowball throwing in teaching grammar and to investigate the benefits of applying snowball throwing. The research was conducted at STKIP Siliwangi Bandung. This study applied qualitative research involving one class consisting of second semester students in English Department who were taking the subject of foundation of English Grammar. The data were obtained from classroom observation and students’ interview. The findings showed that there are seven stages in implementing snowball throwing in teaching grammar. The stages consist of preparing teaching material, forming group, re-explaining the material to the member of the group, formulating question, tossing the ball, answering questions and evaluating teaching and learning process. In addition, the findings also revealed that there are some benefits from applying snowball throwing in teaching grammar such as improving students’ comprehension in learning grammar, creating enjoyable learning atmosphere, increasing students’ vocabulary, developing students’ speaking skill, developing students’ cooperation skill and increasing students’ participation in the class.

  11. Examining Impulse-Variability Theory and the Speed-Accuracy Trade-Off in Children's Overarm Throwing Performance.

    Science.gov (United States)

    Molina, Sergio L; Stodden, David F

    2018-04-01

    This study examined variability in throwing speed and spatial error to test the prediction of an inverted-U function (i.e., impulse-variability [IV] theory) and the speed-accuracy trade-off. Forty-five 9- to 11-year-old children were instructed to throw at a specified percentage of maximum speed (45%, 65%, 85%, and 100%) and hit the wall target. Results indicated no statistically significant differences in variable error across the target conditions (p = .72), failing to support the inverted-U hypothesis. Spatial accuracy results indicated no statistically significant differences with mean radial error (p = .18), centroid radial error (p = .13), and bivariate variable error (p = .08) also failing to support the speed-accuracy trade-off in overarm throwing. As neither throwing performance variability nor accuracy changed across percentages of maximum speed in this sample of children as well as in a previous adult sample, current policy and practices of practitioners may need to be reevaluated.

  12. Performance and Kinematics of Various Throwing Techniques in Team-Handball

    Science.gov (United States)

    Wagner, Herbert; Pfusterschmied, Jürgen; von Duvillard, Serge P.; Müller, Erich

    2011-01-01

    In team-handball competition, the players utilize various throwing techniques that differ in the lower body movements (with and without run-up or jump). These different lower body movements influence changes in the upper body movements and thus also affect the performance. A comprehensive analysis of 3D-kinematics of team-handball throws that may explain these differences in performance is lacking. Consequently, the purpose of this study was (1) to compare performance (ball velocity and throwing accuracy) between the jump throw, standing throw with and without run-up, and the pivot throw; (2) to calculate the influence of kinematic parameters to ball velocity; and (3) to determine if these four throwing techniques differ significantly in kinematics. Three-dimensional kinematic data (angles, angular velocities and their timing, ball velocity and velocity of the center of mass) of 14 elite team-handball players were measured using an 8 camera Vicon MX13 motion capture system (Vicon, Oxford, UK), at 250 Hz. Significant difference was found between the four throwing techniques for ball velocity (p handball players achieved the greatest ball velocity in the standing throw with run-up (100%), followed by the standing throw without run-up (93%), jump throw (92%) and pivot throw (85%). Depending on the floor contact (standing vs. jump throws) the elite players of the study used two different strategies (lead leg braces the body vs. opposed leg movements during flight) to accelerate the pelvis and trunk that caused differences in ball velocity. Elite team-handball players were able to utilize the throwing arm similarly in all four throwing techniques. PMID:24149298

  13. Comparison of In-Season-Specific Resistance vs. A Regular Throwing Training Program on Throwing Velocity, Anthropometry, and Power Performance in Elite Handball Players.

    Science.gov (United States)

    Hermassi, Souhail; van den Tillaar, Roland; Khlifa, Riadh; Chelly, Mohamed Souhaiel; Chamari, Karim

    2015-08-01

    The purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a medicine ball) with that of regular training (throwing with regular balls) on ball velocity, anthropometry, maximal upper-body strength, and power. Thirty-four elite male team handball players (age: 18 ± 0.5 years, body mass: 80.6 ± 5.5 kg, height: 1.80 ± 5.1 m, body fat: 13.4 ± 0.6%) were randomly assigned to 1 of the 3 groups: control (n = 10), resistance training group (n = 12), or regular throwing training group (n = 12). Over the 8-week in season, the athletes performed 3 times per week according to an assigned training program alongside their normal team handball training. One repetition maximum (1RM) bench press and 1RM pullover scores assessed maximal arm strength. Anthropometry was assessed by body mass, fat percentage, and muscle volumes of upper body. Handball throwing velocity was measured by a standing throw, a throw with run, and a jump throw. Power was measured by measuring total distance thrown by a 3-kg medicine ball overhead throw. Throwing ball velocity, maximal strength, power, and muscle volume increases for the specific resistance training group after the 8 weeks of training, whereas only maximal strength, muscle volume and power and in the jump throw increases were found for the regular throwing training group. No significant changes for the control group were found. The current findings suggest that elite male handball players can improve ball velocity, anthropometrics, maximal upper-body strength, and power during the competition season by implementing a medicine ball throwing program.

  14. Throwing in the Middle and Upper Paleolithic: inferences from an analysis of humeral retroversion.

    Science.gov (United States)

    Rhodes, Jill A; Churchill, Steven E

    2009-01-01

    When in evolutionary history did long-range projectile weapons become an important component of hunting toolkits? The archeological evidence for the development of projectile weaponry is complex and generally indirect, and has led to different conclusions about the origin and spread of this technology. Lithic evidence from the Middle Stone Age (MSA) has led some researchers to suggest that true long- range projectile weaponry developed in Africa perhaps as early as 80,000 years ago, and was part of the subsistence toolkit carried by modern humans who expanded out of Africa after 50,000 years ago. Alternatively, temporal patterns in the morphology of pointed lithics has led others to posit an independent, convergent origin of projectile weaponry in Africa, the Near East, and Europe during the interval between 50,000-40,000 years ago. By either scenario, projectile weapons would not have been a component of the hunting arsenal of Neandertals, but may have been in use by European early modern humans and thus, projectile technology may have entered into the competitive dynamics that existed between these two groups. The origins of projectile weapons can be addressed, in part, through analyses of the skeletal remains of the prehistoric humans who made and used them. Habitual behavior patterns--including those related to the production and use of technology--can be imprinted on the skeleton through both genetic and epigenetic pathways. Recent studies in the field of sports medicine indicate that individuals who engage in habitual throwing have increased humeral retroversion angles in their throwing arms and a greater degree of bilateral asymmetry in retroversion angles than do non-throwers. This contribution investigates humeral torsion through analysis of the retroversion angle in samples of Eurasian Neandertals, European early modern humans of the middle and late Upper Paleolithic, and comparative samples of recent humans. This analysis was conducted under the

  15. Examining impulse-variability in overarm throwing.

    Science.gov (United States)

    Urbin, M A; Stodden, David; Boros, Rhonda; Shannon, David

    2012-01-01

    The purpose of this study was to examine variability in overarm throwing velocity and spatial output error at various percentages of maximum to test the prediction of an inverted-U function as predicted by impulse-variability theory and a speed-accuracy trade-off as predicted by Fitts' Law Thirty subjects (16 skilled, 14 unskilled) were instructed to throw a tennis ball at seven percentages of their maximum velocity (40-100%) in random order (9 trials per condition) at a target 30 feet away. Throwing velocity was measured with a radar gun and interpreted as an index of overall systemic power output. Within-subject throwing velocity variability was examined using within-subjects repeated-measures ANOVAs (7 repeated conditions) with built-in polynomial contrasts. Spatial error was analyzed using mixed model regression. Results indicated a quadratic fit with variability in throwing velocity increasing from 40% up to 60%, where it peaked, and then decreasing at each subsequent interval to maximum (p < .001, η2 = .555). There was no linear relationship between speed and accuracy. Overall, these data support the notion of an inverted-U function in overarm throwing velocity variability as both skilled and unskilled subjects approach maximum effort. However, these data do not support the notion of a speed-accuracy trade-off. The consistent demonstration of an inverted-U function associated with systemic power output variability indicates an enhanced capability to regulate aspects of force production and relative timing between segments as individuals approach maximum effort, even in a complex ballistic skill.

  16. Efficient Unbiased Rendering using Enlightened Local Path Sampling

    DEFF Research Database (Denmark)

    Kristensen, Anders Wang

    measurements, which are the solution to the adjoint light transport problem. The second is a representation of the distribution of radiance and importance in the scene. We also derive a new method of particle sampling, which is advantageous compared to existing methods. Together we call the resulting algorithm....... The downside to using these algorithms is that they can be slow to converge. Due to the nature of Monte Carlo methods, the results are random variables subject to variance. This manifests itself as noise in the images, which can only be reduced by generating more samples. The reason these methods are slow...... is because of a lack of eeffective methods of importance sampling. Most global illumination algorithms are based on local path sampling, which is essentially a recipe for constructing random walks. Using this procedure paths are built based on information given explicitly as part of scene description...

  17. Energy-Aware Path Planning for UAS Persistent Sampling and Surveillance

    Science.gov (United States)

    Shaw-Cortez, Wenceslao

    The focus of this work is to develop an energy-aware path planning algorithm that maximizes UAS endurance, while performing sampling and surveillance missions in a known, stationary wind environment. The energy-aware aspect is specifically tailored to extract energy from the wind to reduce thrust use, thereby increasing aircraft endurance. Wind energy extraction is performed by static soaring and dynamic soaring. Static soaring involves using upward wind currents to increase altitude and potential energy. Dynamic soaring involves taking advantage of wind gradients to exchange potential and kinetic energy. The path planning algorithm developed in this work uses optimization to combine these soaring trajectories with the overarching sampling and surveillance mission. The path planning algorithm uses a simplified aircraft model to tractably optimize soaring trajectories. This aircraft model is presented and along with the derivation of the equations of motion. A nonlinear program is used to create the soaring trajectories based on a given optimization problem. This optimization problem is defined using a heuristic decision tree, which defines appropriate problems given a sampling and surveillance mission and a wind model. Simulations are performed to assess the path planning algorithm. The results are used to identify properties of soaring trajectories as well as to determine what wind conditions support minimal thrust soaring. Additional results show how the path planning algorithm can be tuned between maximizing aircraft endurance and performing the sampling and surveillance mission. A means of trajectory stitching is demonstrated to show how the periodic soaring segments can be combined together to provide a full solution to an infinite/long horizon problem.

  18. PERFORMANCE AND KINEMATICS OF VARIOUS THROWING TECHNIQUES IN TEAM-HANDBALL

    Directory of Open Access Journals (Sweden)

    Herbert Wagner

    2011-03-01

    Full Text Available In team-handball competition, the players utilize various throwing techniques that differ in the lower body movements (with and without run-up or jump. These different lower body movements influence changes in the upper body movements and thus also affect the performance. A comprehensive analysis of 3D-kinematics of team-handball throws that may explain these differences in performance is lacking. Consequently, the purpose of this study was (1 to compare performance (ball velocity and throwing accuracy between the jump throw, standing throw with and without run-up, and the pivot throw; (2 to calculate the influence of kinematic parameters to ball velocity; and (3 to determine if these four throwing techniques differ significantly in kinematics. Three-dimensional kinematic data (angles, angular velocities and their timing, ball velocity and velocity of the center of mass of 14 elite team-handball players were measured using an 8 camera Vicon MX13 motion capture system (Vicon, Oxford, UK, at 250 Hz. Significant difference was found between the four throwing techniques for ball velocity (p < 0. 001, maximal velocity of the center of mass in goal-directed movement (p < 0.001, and 15 additional kinematic variables (p < 0.003. Ball velocity was significant impacted by the run-up and the pelvis and trunk movements. Depending on floor contact (standing vs. jump throws, elite players in the study used two different strategies (lead leg braces the body vs. opposed leg movements during flight to accelerate the pelvis and trunk to yield differences in ball velocity. However, these players were able to utilize the throwing arm similarly in all four throwing techniques.

  19. Entropic sampling in the path integral Monte Carlo method

    International Nuclear Information System (INIS)

    Vorontsov-Velyaminov, P N; Lyubartsev, A P

    2003-01-01

    We have extended the entropic sampling Monte Carlo method to the case of path integral representation of a quantum system. A two-dimensional density of states is introduced into path integral form of the quantum canonical partition function. Entropic sampling technique within the algorithm suggested recently by Wang and Landau (Wang F and Landau D P 2001 Phys. Rev. Lett. 86 2050) is then applied to calculate the corresponding entropy distribution. A three-dimensional quantum oscillator is considered as an example. Canonical distributions for a wide range of temperatures are obtained in a single simulation run, and exact data for the energy are reproduced

  20. The Relationship of Throwing Arm Mechanics and Elbow Varus Torque: Within-Subject Variation for Professional Baseball Pitchers Across 82,000 Throws.

    Science.gov (United States)

    Camp, Christopher L; Tubbs, Travis G; Fleisig, Glenn S; Dines, Joshua S; Dines, David M; Altchek, David W; Dowling, Brittany

    2017-11-01

    Likely due to the high level of strain exerted across the elbow during the throwing motion, elbow injuries are on the rise in baseball. To identify at-risk athletes and guide postinjury return-to-throw programs, a better understanding of the variables that influence elbow varus torque is desired. To describe the within-subject relationship between elbow varus torque and arm slot and arm rotation in professional baseball pitchers. Descriptive laboratory study. A total of 81 professional pitchers performed 82,000 throws while wearing a motusBASEBALL sensor and sleeve. These throws represented a combination of throw types, such as warm-up/catch, structured long-toss, bullpen throwing from a mound, and live game activity. Variables recorded for each throw included arm slot (angle of the forearm relative to the ground at ball release), arm speed (maximal rotational velocity of the forearm), arm rotation (maximal external rotation of the throwing arm relative to the ground), and elbow varus torque. Linear mixed-effects models and likelihood ratio tests were used to estimate the relationship between elbow varus torque and arm slot, arm speed, and arm rotation within individual pitchers. All 3 metrics-arm slot (χ 2 = 428, P relationship with elbow varus torque. Within individual athletes, a 1-N.m increase in elbow varus torque was associated with a 13° decrease in arm slot, a 116 deg/s increase in arm speed, and an 8° increase in arm rotation. Elbow varus torque increased significantly as pitchers increased their arm rotation during the arm cocking phase, increased the rotational velocity of their arm during the arm acceleration phase of throwing, and decreased arm slot at ball release. Thus, shoulder flexibility, arm speed, and elbow varus torque (and likely injury risk) are interrelated and should be considered collectively when treating pitchers. It is well established that elbow varus torque is related to ulnar collateral ligament injuries in overhead throwers. This

  1. Throwing behavior and mass distribution of stone selection in tufted capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Cleveland, A; Rocca, A R; Wendt, E L; Westergaard, G C

    2003-12-01

    Cannell [Journal of Archaeological Science 29:335-339, 2002] argued that sex-based differences among humans in terms of the mass of chosen throwing stones could be used to infer body mass and patterns of sexual dimorphism in early hominids from Olduvai and Koobi Fora by examining the mass distributions of unaltered stone tools at those sites. We examined this hypothesis in tufted capuchin monkeys using a comparative approach, by investigating the relationships among body mass, sex, stone weight preference, and accuracy in a throwing task. The subject sample consisted of nine monkeys trained to perform an aimed-throwing task in which a food reward could be obtained by throwing a stone into a bucket. We found that 1) the subjects showed a strong mean stone mass preference; 2) the females chose heavier stones than the males, in terms of absolute mean selected stone mass and selected stone mass relative to body mass; 3) subjects threw more accurately when they used stones of preferred mass vs. stones of nonpreferred mass; and 4) overall, the males were more accurate in the throwing task than the females. We conclude that capuchins are highly selective when choosing throwing stones, and that this confers an advantage for throwing accuracy. Our results indicate that the sexually dimorphic pattern in stone mass preference observed among humans does not generalize to Cebus apella. We suggest that researchers examining this pattern in humans in an attempt to explain early hominid patterns of dimorphism and behavior should take into account not only stone weight preference, but also its adaptive advantage. Copyright 2003 Wiley-Liss, Inc.

  2. KEEFEKTIFAN PEMBELAJARAN SNOWBALL THROWING BERBANTUAN LEMBAR KEGIATAN SISWA

    Directory of Open Access Journals (Sweden)

    Gallant Alim Purbowo

    2012-06-01

    Full Text Available Abstract Tujuan penelitian ini adalah untuk mengetahui keefektifan pembelajaran Snowball Throwing berbantuan LKS terhadap hasil belajar siswa kelas VIII SMP Negeri 1 Kaliori pada materi lingkaran tahun ajaran 2011/2012. Populasi dalam penelitian ini adalah semua siswa kelas VIII SMP Negeri 1 Kaliori tahun ajaran 2011/2012. Sampel dalam penelitian ini diambil secara cluster random sampling. Data hasil penelitian diperoleh dengan metode tes yang dianalisis dengan menggunakan uji proporsi, uji rata-rata, uji kesamaan dua proporsi, dan uji perbedaan dua rata-rata untuk menguji hipotesis. Hasil penelitian menunjukkan: (1 zhitung =0,5>-(z(0,5-? =-1,64, artinya siswa yang tuntas terhadap hasil belajar pada kelas eksperimen dapat mencapai persentase ketuntasan minimal siswa, (2 thitung=3,9001 >t(1-? =1,69 artinya rata-rata hasil belajar siswa pada kelas eksperimen dapat mencapai KKM, (3 zhitung=2,335>z(0.5-? =1,64, artinya siswa yang tuntas pada kelas eksperimen lebih besar dari kelas kontrol, (4 thitung=2,0194 ? 1,668, artinya rata-rata hasil belajar siswa pada kelas eksperimen lebih dari kelas kontrol. Berdasarkan hasil penelitian tersebut dapat disimpulkan bahwa penerapan Pembelajaran Snowball Throwing berbantuan LKS efektif terhadap hasil belajar siswa kelas VIII SMP Negeri 1 Kaliori pada materi lingkaran. The purpose of this study was to determine the effectiveness of Snowball Throwing learning assisted students worksheets to learning outcomes of VIII grade in SMP Negeri 1 Kaliori in circle material of the school year 2011/2012. The population in this study were all students in VIII grade SMP Negeri 1 Kaliori academic year 2011/2012. The sample in this study were drawn by cluster random sampling. Research data obtained with the test method were analyzed using the proportion test, test averages, test the equality of two proportions, and test the average difference in the two hypotheses. The results showed: (1 zcount = 0.5> - z(0,5-? = -1.64, meaning

  3. The Kinetic Chain Revisited: New Concepts on Throwing Mechanics and Injury.

    Science.gov (United States)

    Chu, Samuel K; Jayabalan, Prakash; Kibler, W Ben; Press, Joel

    2016-03-01

    The overhead throwing motion is a complex activity that is achieved through activation of the kinetic chain. The kinetic chain refers to the linkage of multiple segments of the body that allows for transfer of forces and motion. The lower extremities and core provide a base of support, generating energy that is transferred eventually through the throwing arm and hand, resulting in release of the ball. The kinetic chain requires optimal anatomy, physiology, and mechanics and is involved in all 6 phases of overhead throwing: windup, stride, arm cocking, acceleration, deceleration, and follow-through. Breaks or deficits in the kinetic chain can lead to injury or decreased performance. Through an understanding of the mechanics and pathomechanics seen in each phase of throwing, the clinician can better evaluate and screen for potential kinetic chain deficits in the overhead throwing athlete. The purpose of this article is to review the biomechanics of the overhead throwing motion, the role of the kinetic chain in throwing, and the clinical evaluation and management of abnormal throwing mechanics and related injuries. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  4. Changing Throwing Pattern: Instruction and Control Parameter

    Science.gov (United States)

    Southard, Dan

    2006-01-01

    The purpose of this study was to determine the effects of instruction and scaling up a control parameter (velocity of throw) on changes in throwing pattern. Sixty adult female throwers (ages 20-26 years) were randomly placed into one of four practice conditions: (a) scale up on velocity with no instruction, (b) maintain constant velocity with no…

  5. Efektivitas Pembelajaran Matematika melalui Penerapan Model Pembelajaran Kooperatif Tipe Snowball Throwing

    Directory of Open Access Journals (Sweden)

    Andi Mulawakkan Firdaus

    2016-10-01

    Full Text Available [Bahasa]: Penelitian ini merupakan penelitian Eksperimen semu yang bertujuan untuk mendeskripsikan hasil belajar siswa SMP Negeri 13 Makassar yang diajar dengan menggunakan Model Kooperatif Tipe Snowball Throwing dan Metode Ekspositori, serta untuk mengetahui apakah model pembelajaran kooperatif tipe Snowball Throwing efektif digunakan dalam pembelajaran matematika pada siswa kelas VIII SMP Negeri 13 Makassar. Luaran yang akan dihasilkan dari penelitian ini adalah penerapan alternatif pembelajaran yang tidak monoton sehingga dapat meningkatkan hasil belajar matematika siswa dan perangkat pembelajaran (silabus dan RPP yang berorientasi pada pembelajaran koperatif tipe Snowball Throwing. Subjek penelitian dibagi dalam 2 kelompok, yakni kelompok eksperimen yang diajar dengan menggunakan pembelajaran kooperatif tipe Snowball Throwing dan kelompok kontrol yang diajar dengan menggunakan metode ekspositori. Setiap kelompok diajar dengan frekuensi pertemuan yang sama dengan materi yang sama. Hasil penelitian menunjukan bahwa penerapan model pembelajaran kooperatif tipe Snowball Throwing lebih efektif jika dibandingkan dengan penerapan metode ekspositori untuk pokok bahasan sistem persamaan linear dua variabel. [English]: This experiment research aims to describe the learning outcomes of students at SMP Negeri 13 Makassar taught with snowball throwing (cooperative and expository method and to find out whether snowball throwing method is more effective in learning mathematics than the expository method in grade 7. The results of this research are implementing alternative learning method which is not monotonous to improve students' mathematics learning outcomes and producing learning tools that consist of syllabus and lesson plans based on snowball throwing method in cooperative learning. Research subjects are divided into two groups namely the experimental group taught with snowball throwing and the control group taught with the expository method. Each

  6. Effects of Six Weeks of Medicine Ball Training on Throwing Velocity, Throwing Precision, and Isokinetic Strength of Shoulder Rotators in Female Handball Players.

    Science.gov (United States)

    Raeder, Christian; Fernandez-Fernandez, Jaime; Ferrauti, Alexander

    2015-07-01

    The aim of this study was to investigate the effects of 6 weeks of medicine ball training (MBT) on throwing velocity, throwing precision, and isokinetic strength of shoulder rotators in competitive female handball players. Twenty-eight players (mean ± SD; age: 20.8 ± 3.3 years, height: 170.5 ± 5.6 cm, body mass: 65.2 ± 8.0 kg) were randomly assigned to an MBT group (TG; n = 15) and a control group (CG; n = 13). TG performed a supervised MBT program, 3 times a week for a total of 6 weeks, focusing on handball-specific movement patterns. Both groups, TG and CG, also conducted a supervised shoulder injury prevention program with elastic tubes, as part of the warm-up, finishing with regular handball throws. Results showed a significant group × time interaction in throwing velocity (p handball players, whereas throwing precision remained unaffected. Medicine ball training exercises seem to be a useful and inexpensive strength training strategy in enhancing functional performance by closely mimicking sport-specific movement activities.

  7. CONNECTION OF FUNCTIONAL ABILITIES WITH JUMPING AND THROWING ATHLETIC DISCIPLINES

    OpenAIRE

    Igor Stanojević; Dejan Milenković

    2014-01-01

    The aim of this study was to determine the connection between functional abilities with results of jumping and throwing athletic disciplines with athletes. The sample was taken from a population of elementary school students from Prokuplje region, 13 and 14 old, included in regular physical education classes. The sample consisted of 200 male athletes involved in the training process in sports clubs at least three times a week in addition to physical education classes. For assessment of functi...

  8. KINEMATIC ANALYSIS OF LINE-OUT THROWING IN ELITE INTERNATIONAL RUGBY UNION

    Directory of Open Access Journals (Sweden)

    Mark G.L. Sayers

    2011-09-01

    Full Text Available The rugby union line-out is a key aspect of game play and involves players from both teams contesting for the ball after it has been thrown in from the side line. Successful lines-out throws require the ball to be delivered accurately to the hands of a jumping and/or lifted team mate (approximately 3-3.5 m off the ground over distances of between 5- 18 m. Previous research has suggested considerable inter and intra-individual differences in the throwing techniques of international level players. Accordingly, this project investigated the interrelationships between accuracy and the line-out throwing characteristics of three elite international rugby players, and then analyzed whether these changed for throws over increasing length. Three-dimensional (3D data were developed from video footage (50 Hz of three elite international subjects for 30 throws over three distances (6 m, 10 m, and 15 m. Results showed notable differences between subjects in many variables at each of the key throw phases. However, several variables such as the degree of trunk flexion at the end of the backswing and at ball release, coupled with elbow flexion angle at ball release remained constant as throw length increased. All subjects exhibited high levels of consistency in movement patterns across all throw lengths. Findings indicated that these high performance line-out throwers shared several common characteristics that will provide useful guides in the development of training programs

  9. The optical design of ultra-short throw system for panel emitted theater video system

    Science.gov (United States)

    Huang, Jiun-Woei

    2015-07-01

    In the past decade, the display format from (HD High Definition) through Full HD(1920X1080) to UHD(4kX2k), mainly guides display industry to two directions: one is liquid crystal display(LCD) from 10 inch to 100 inch and more, and the other is projector. Although LCD has been popularly used in market; however, the investment for production such kind displays cost more money expenditure, and less consideration of environmental pollution and protection[1]. The Projection system may be considered, due to more viewing access, flexible in location, energy saving and environmental protection issues. The topic is to design and fabricate a short throw factor liquid crystal on silicon (LCoS) projection system for cinema. It provides a projection lens system, including a tele-centric lens fitted for emitted LCoS to collimate light to enlarge the field angle. Then, the optical path is guided by a symmetric lens. Light of LCoS may pass through the lens, hit on and reflect through an aspherical mirror, to form a less distortion image on blank wall or screen for home cinema. The throw ratio is less than 0.33.

  10. Effect of Core Training on Male Handball Players' Throwing Velocity.

    Science.gov (United States)

    Manchado, Carmen; García-Ruiz, José; Cortell-Tormo, Juan Manuel; Tortosa-Martínez, Juan

    2017-02-01

    In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ± 3.4 years, body height 179.3 ± 7.0 cm, body mass 78.9 ± 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control group (n = 15) and the experimental group (n = 15). For a period of ten weeks, both groups attended their regular handball training sessions (four per week), but in addition, the experimental group participated in a program specifically aimed at progressively strengthening the lumbo-pelvic region and consisting of seven exercises performed after the general warm-up in each regular session. Pre- and post-tests were carried out to analyze each player's throwing velocity from different throwing positions and thus assess the effects of this specific training program. Statistically significant differences (p ≤ 0.05) in throwing velocity were observed between the experimental group, which presented a percentage improvement of 4.5%, and the control group, which did not show any improvement. The results seem to indicate that an increase in the strength and stability of the lumbo-pelvic region can contribute to an improvement in the kinetic chain of the specific movement of throwing in handball, thus, increasing throwing velocity.

  11. Effect of Core Training on Male Handball Players’ Throwing Velocity

    Science.gov (United States)

    García-Ruiz, José; Cortell-Tormo, Juan Manuel; Tortosa-Martínez, Juan

    2017-01-01

    Abstract In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ± 3.4 years, body height 179.3 ± 7.0 cm, body mass 78.9 ± 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control group (n = 15) and the experimental group (n = 15). For a period of ten weeks, both groups attended their regular handball training sessions (four per week), but in addition, the experimental group participated in a program specifically aimed at progressively strengthening the lumbo-pelvic region and consisting of seven exercises performed after the general warm-up in each regular session. Pre- and post-tests were carried out to analyze each player’s throwing velocity from different throwing positions and thus assess the effects of this specific training program. Statistically significant differences (p ≤ 0.05) in throwing velocity were observed between the experimental group, which presented a percentage improvement of 4.5%, and the control group, which did not show any improvement. The results seem to indicate that an increase in the strength and stability of the lumbo-pelvic region can contribute to an improvement in the kinetic chain of the specific movement of throwing in handball, thus, increasing throwing velocity. PMID:28469756

  12. Rare events via multiple reaction channels sampled by path replica exchange

    NARCIS (Netherlands)

    Bolhuis, P.G.

    2008-01-01

    Transition path sampling (TPS) was developed for studying activated processes in complex systems with unknown reaction coordinate. Transition interface sampling (TIS) allows efficient evaluation of the rate constants. However, when the transition can occur via more than one reaction channel

  13. Simulation and experimental research on line throwing rocket with flight

    Directory of Open Access Journals (Sweden)

    Wen-bin Gu

    2014-06-01

    Full Text Available The finite segment method is used to model the line throwing rocket system. A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system and the consideration of the forces acting on the system. The experiment designed according to the parameters of the dynamic model is made. The simulation and experiment results, such as range, velocity and flight time, are compared and analyzed. The simulation results are basically agreed with the test data, which shows that the flight motion of the line throwing rocket can be predicted by the dynamic model. A theoretical model and guide for the further research on the disturbance of rope and the guidance, flight control of line throwing rocket are provided by the dynamic modeling.

  14. Strength and Power Correlates of Throwing Velocity on Subelite Male Cricket Players.

    Science.gov (United States)

    Freeston, Jonathan L; Carter, Thomas; Whitaker, Gary; Nicholls, Owen; Rooney, Kieron B

    2016-06-01

    Throwing velocity is an important aspect of fielding in cricket to affect run-outs and reduce the opponent's run-scoring opportunities. Although a relationship between strength and/or power and throwing velocity has been well established in baseball, water polo, and European handball, it has not been adequately explored in cricket. Consequently, this study aimed to determine the relationship between measures of strength and/or power and throwing velocity in cricket players. Seventeen male cricket players (mean ± SD; age, 21.1 ± 1.6 years; height, 1.79 ± 0.06 m; weight, 79.8 ± 6.4 kg) from an elite athlete program were tested for maximal throwing velocity from the stretch position and after a 3-meter shuffle. They were also assessed for strength and power using a range of different measures. Throwing velocity from the stretch position (30.5 ± 2.4 m·s) was significantly related to dominant leg lateral-to-medial jump (LMJ) distance (r = 0.71; p velocity and medicine ball chest pass (MB CP) distance (r = 0.67; p bench press strength (p = 0.90), height (p = 0.33), or weight (p = 0.29). Multiple regression analysis revealed that dominant MB Rot and MB CP explained 66% of the variance. The results were similar for velocity after a shuffle step (31.8 ± 2.1 m·s); however, VJ height reached statistical significance (r = 0.51; p ≤ 0.05). The multiple regression was also similar with MB Rot and MB CP explaining 70% of the variance. The cricketers in this study threw with greater velocity than elite junior and subelite senior cricketers but with lower velocities than elite senior cricketers and collegiate level and professional baseball players. This is the first study to demonstrate a link between strength and/or power and throwing velocity in cricket players and highlight the importance of power development as it relates to throwing velocity. Exercises that more closely simulated the speed (body weight jumps and medicine ball throws) or movement pattern (shoulder IR

  15. Plastic forming simulation analysis of marine engine crankshaft single-throw

    Directory of Open Access Journals (Sweden)

    LIU Peipei

    2016-08-01

    Full Text Available The research object is for marine engine crankshaft single-throw.A 3D model of the crankshaft single-throw blank and die in forging process is established by SolidWorks software,then the 3D model is imported into metal plastic forming CAE software DEFROM-3D to carry on the plastic forming simulation,to verify the relationship between the internal flow stress and the external deformation conditions in the process of metal plastic deformation under different strain rate and temperature,and to carry on the scientific analysis based on the obtained data.The result shows that the preset temperature is higher,the stress-strain curve is relatively lower when the strain rate is constant.Sample internal flow stress will be greater and the resistance to fatigue strength will be poorer at a higher strain rate when the temperature of the blank is constant.The result also provides a theoretical basis for further optimization design.

  16. Relationship among maximal grip, throwing velocity and anthropometric parameters in elite water polo players.

    Science.gov (United States)

    Ferragut, C; Vila, H; Abraldes, J A; Argudo, F; Rodriguez, N; Alcaraz, P E

    2011-03-01

    As independent aspects, body size, body composition, and physiological performance of elite athletes have aroused the interest of sports scientists but, unfortunately, studies that combine these aspects are scarcely avalaible in water polo. The aim of the present study was to: 1) to develop an anthropometric profile of highly skilled male Water Polo players, and 2) to identify significant relationships between these features and overhead throwing velocity in highly skilled male water polo players. Thirteen male water polo players, with a mean age of 26.10±4.82, were recruited from the Spanish Water Polo team and an anthropometric assessment on all of them was carried out. Throwing velocity was evaluated in three different situations from the 5 m-penalty line on the center of the water polo goal: A) throwing without a defender nor a goalkeeper; B) throwing with a goalkeeper only, and C) 3) armfuls running shot with goalkeeper. Maximal handgrip was also tested. Biacromial breadth shows a significative correlation with hand grip in water polo players (r=0.792; P=0.001) and also correlates with Throwing velocity (r=0.716; P<0.001). Biepicondylar femur breadth correlates significatively with hand grip (r=0.727; P<0.05) and also with throwing velocity in "throwing with goalkeeper" situation (r=0.664; P<0.05). Hand grip shows a significant correlation with throwing velocity in "throwing with goalkeeper" situation (r=0.603; P<0.05). In conclusion, body mass aspects are not related with throwing velocity in highly skilled Water Polo players. Maximal hand grip is related with throwing velocity in "throwing with goalkeeper" situation. More investigations about water polo are necessary.

  17. EFFECTS OF STRENGTH VS. BALLISTIC-POWER TRAINING ON THROWING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Nikolaos Zaras

    2013-03-01

    Full Text Available The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9 and Power (n = 8 groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ, Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively. Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively, while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05. Muscle fibre Cross Sectional Area (fCSA increased in all fibre types after Strength training by 19-26% (p < 0.05, while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (% decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations

  18. BASIC TECHNICAL SKILLS (THROWS IN 17-19-YEAR-OLD JUDOKAS

    Directory of Open Access Journals (Sweden)

    Wladyslaw Jagiello

    2014-12-01

    Full Text Available Purpose: The purpose of the research was to determine basic technical skills (throws in 17-19-year-old judokas and the level of their performance. Material: The study involved 30 judo athletes (aged 17-19. Results: To determine the athletes’ basic technical skills (throws, an analysis of source materials and a diagnostic survey were used. To determine the level of technical skills, the method of expert assessment was applied. Statistical software package Statistica 8 was used in the statistical analysis. In the coaches’ opinion, 17-19-year-old judokas have a specific, characteristic of this age group, set of basic technical skills (throws aptly defining their technical preparation. Conclusions: The tested group of judokas exhibited the highest level of demonstrating throws of the koshi-waza (hip group, and the lowest one of the ashi-waza (foot group.

  19. Throwing velocities, anthropometric characteristics, and efficacy indices of women's European water polo subchampions.

    Science.gov (United States)

    Alcaraz, Pedro E; Abraldes, J Arturo; Ferragut, Carmen; Rodríguez, Nuria; Argudo, Francisco M; Vila, Helena

    2011-11-01

    Water polo is a team sport characterized by a high-intensity, intermittent activity, where technical and tactical aspect are of a great importance. For that reason, the main aim of this study was to define the anthropometrical characteristics, maximum isometric grip strength, training and competition throwing velocities, and the efficacy indices in female high-level water polo players. A second purpose was to examine the differences between the throwing velocities in training vs. European championships in the water polo female national team. Ten elite trained female water polo players participated in this study. Before the competitive phase of their season, the following measures were taken: standard anthropometry, static and dynamic training throwing velocities, and hand-grip dynamometry. In the competitive phase, efficacy indices, average and maximum throwing velocities from all the participants were also determined. Significant differences (p ≤ 0.05) were found between different training situations and different competitive throwing velocities. We concluded that elite female water polo players modify their throwing velocity depending if the throw is performed during training or competitive situation.

  20. Data-Based Interval Throwing Programs for Collegiate Softball Players

    Science.gov (United States)

    Axe, Michael J.; Windley, Thomas C.; Snyder-Mackler, Lynn

    2002-01-01

    Objective: To construct interval throwing programs followed by a simulated game for collegiate softball players at all positions. The programs are intended to be used as functional progressions within a comprehensive rehabilitation program for an injured athlete or to augment off-season conditioning workouts. Design and Setting: We collected data over a single season of National Collegiate Athletic Association softball at the University of Delaware and Goldey Beacom College. We observed 220 half-innings of play and 2785 pitches during data collection. Subjects: The subjects were collegiate-level softball players at all positions of play. Measurements: We recorded the number of pitches for pitchers. For catchers, we recorded the number of sprints to back up a play, time in the squat stance, throws back to the pitcher, and the perceived effort and distance of all other throws. We also collected the perceived effort and distance of all throws for infielders and outfielders. Results: Pitchers threw an average of 89.61 pitches per game; catchers were in the squat stance 14.13 minutes per game; infielders threw the ball between 4.28 times per game and 6.30 times per game; and outfielders threw distances of up to 175 feet. Conclusions: We devised the interval throwing programs from the data collected, field dimensions, the types of injuries found to occur in softball, and a general understanding of tissue healing. We designed programs that allow a safe and efficient progressive return to sport. PMID:12937435

  1. The Acute Effects of Upper Extremity Stretching on Throwing Velocity in Baseball Throwers

    Directory of Open Access Journals (Sweden)

    Michael Williams

    2013-01-01

    Full Text Available Purpose. To examine the effects of static and proprioceptive neuromuscular facilitation (PNF stretching of the shoulder internal rotators on throwing velocity. Subjects. 27 male throwers (mean age = 25.1 years old, SD = 2.4 with adequate knowledge of demonstrable throwing mechanics. Study Design. Randomized crossover trial with repeated measures. Methods. Subjects warmed up, threw 10 pitches at their maximum velocity, were randomly assigned to 1 of 3 stretching protocols (static, PNF, or no stretch, and then repeated their 10 pitches. Velocities were recorded after each pitch and average and peak velocities were recorded after each session. Results. Data were analyzed using a repeated measures ANOVA. No significant interaction between stretching and throwing velocity was observed. Main effects for time were not statistically significant. Main effects for the stretching groups were statistically significant. Discussion. Results suggest that stretching of the shoulder internal rotators did not significantly affect throwing velocity immediately after stretching. This may be due to the complexity of the throwing task. Conclusions. Stretching may be included in a thrower's warm-up without any effects on throwing velocity. Further research should be performed using a population with more throwing experience and skill.

  2. Influence Of Opposition On Ball Velocity In The Handball Jump Throw

    Science.gov (United States)

    Rivilla-Garcia, Jesús; Grande, Ignacio; Sampedro, Javier; Van Den Tillaar, Roland

    2011-01-01

    The purpose of the present study was to investigate the influence of different degrees of opposition on ball velocity in the jump throw in elite, amateur and adolescent team handball players. Thus, one hundred and nineteen elite, amateur and under 18 team handball players performed jump throws under three different conditions: 1) without opposition, 2) with the opposition of the goalkeeper and 3) with the opposition of the goalkeeper and a defensive player. The degree of opposition was found to have a negative effect on ball velocity in all three groups (p handball players in the jump throw. It indicated that an increase of external stimuli influences the execution of throwing. Experience does not seem to be a factor that can reduce the influence of these external stimuli. PMID:24150629

  3. Advanced path sampling of the kinetic network of small proteins

    NARCIS (Netherlands)

    Du, W.

    2014-01-01

    This thesis is focused on developing advanced path sampling simulation methods to study protein folding and unfolding, and to build kinetic equilibrium networks describing these processes. In Chapter 1 the basic knowledge of protein structure and folding theories were introduced and a brief overview

  4. Multiple Wheel Throwing: And Chess Sets.

    Science.gov (United States)

    Sapiro, Maurice

    1978-01-01

    A chess set project is suggested to teach multiple throwing, the creation on a potter's wheel of several pieces of similar configuration. Processes and finished sets are illustrated with photographs. (SJL)

  5. Developmental Gender Differences for Overhand Throwing in Aboriginal Australian Children

    Science.gov (United States)

    Thomas, Jerry R.; Alderson, Jacqueline A.; Thomas, Katherine T.; Campbell, Amity C.; Elliott, Bruce C.

    2010-01-01

    In a review of 46 meta-analyses of gender differences, overhand throwing had the largest gender difference favoring boys (ES greater than 3.0). Expectations for gender-specific performances may be less pronounced in female Australian Aborigines, because historical accounts state they threw for defense and hunting. Overhand throwing velocities and…

  6. Accelerated sampling by infinite swapping of path integral molecular dynamics with surface hopping

    Science.gov (United States)

    Lu, Jianfeng; Zhou, Zhennan

    2018-02-01

    To accelerate the thermal equilibrium sampling of multi-level quantum systems, the infinite swapping limit of a recently proposed multi-level ring polymer representation is investigated. In the infinite swapping limit, the ring polymer evolves according to an averaged Hamiltonian with respect to all possible surface index configurations of the ring polymer and thus connects the surface hopping approach to the mean-field path-integral molecular dynamics. A multiscale integrator for the infinite swapping limit is also proposed to enable efficient sampling based on the limiting dynamics. Numerical results demonstrate the huge improvement of sampling efficiency of the infinite swapping compared with the direct simulation of path-integral molecular dynamics with surface hopping.

  7. Can an inadequate cervical cytology sample in ThinPrep be converted to a satisfactory sample by processing it with a SurePath preparation?

    Science.gov (United States)

    Sørbye, Sveinung Wergeland; Pedersen, Mette Kristin; Ekeberg, Bente; Williams, Merete E Johansen; Sauer, Torill; Chen, Ying

    2017-01-01

    The Norwegian Cervical Cancer Screening Program recommends screening every 3 years for women between 25 and 69 years of age. There is a large difference in the percentage of unsatisfactory samples between laboratories that use different brands of liquid-based cytology. We wished to examine if inadequate ThinPrep samples could be satisfactory by processing them with the SurePath protocol. A total of 187 inadequate ThinPrep specimens from the Department of Clinical Pathology at University Hospital of North Norway were sent to Akershus University Hospital for conversion to SurePath medium. Ninety-one (48.7%) were processed through the automated "gynecologic" application for cervix cytology samples, and 96 (51.3%) were processed with the "nongynecological" automatic program. Out of 187 samples that had been unsatisfactory by ThinPrep, 93 (49.7%) were satisfactory after being converted to SurePath. The rate of satisfactory cytology was 36.6% and 62.5% for samples run through the "gynecology" program and "nongynecology" program, respectively. Of the 93 samples that became satisfactory after conversion from ThinPrep to SurePath, 80 (86.0%) were screened as normal while 13 samples (14.0%) were given an abnormal diagnosis, which included 5 atypical squamous cells of undetermined significance, 5 low-grade squamous intraepithelial lesion, 2 atypical glandular cells not otherwise specified, and 1 atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion. A total of 2.1% (4/187) of the women got a diagnosis of cervical intraepithelial neoplasia 2 or higher at a later follow-up. Converting cytology samples from ThinPrep to SurePath processing can reduce the number of unsatisfactory samples. The samples should be run through the "nongynecology" program to ensure an adequate number of cells.

  8. Determinant Factors of Physical Performance and Specific Throwing in Handball Players of Different Ages.

    Science.gov (United States)

    Ortega-Becerra, Manuel; Pareja-Blanco, Fernando; Jiménez-Reyes, Pedro; Cuadrado-Peñafiel, Víctor; González-Badillo, Juan J

    2018-06-01

    Ortega-Becerra, M, Pareja-Blanco, F, Jiménez-Reyes, P, Cuadrado-Peñafiel, V, and González-Badillo, JJ. Determinant factors of physical performance and specific throwing in handball players of different ages. J Strength Cond Res 32(6): 1778-1786, 2018-This study aimed to analyze various fitness qualities in handball players of different ages and to determine the relationships between these parameters and throwing velocity. A total of 44 handball players participated, pooled by age groups: professional (ELITE, n = 13); under-18 (U18, n = 16); under-16 (U16, n = 15). The following tests were completed: 20-m running sprints; countermovement jumps (CMJs); jump squat to determine the load that elicited ∼20 cm jump height (JSLOAD-20 cm); a progressive loading test in full squat and bench press to determine the load that elicited ∼1 m·s (SQ-V1-LOAD and BP-V1-LOAD); and handball throwing (jump throw and 3-step throw). ELITE showed greater performance in almost all sprint distances, CMJ, JSLOAD-20 cm, and bench press strength than U18 and U16. The differences between U18 and U16 were unclear for these variables. ELITE also showed greater (p handball throwing velocity is strongly associated with lower-limb strength, although upper-limb strength, jumping and sprint capacities also play a relevant role in throwing performance, suggesting the need for coaches to include proper strength programs to improve handball players' throwing velocity.

  9. Comparison of three types of full‐body compression garments on throwing and repeat‐sprint performance in cricket players

    Science.gov (United States)

    Duffield, Rob; Portus, Marc

    2007-01-01

    Objective To compare the effects of three types of full‐body compression garments (Skins, Adidas and Under Armour) on repeat‐sprint and throwing performance in cricket players. Methods Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat‐sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre‐exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O2 saturation and O2 partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. Results No significant differences (p>0.05) were evident in repeat‐sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p0.05). Conclusions No benefit was noted when wearing compression garments for repeat‐sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness. PMID:17341589

  10. Comparison of three types of full-body compression garments on throwing and repeat-sprint performance in cricket players.

    Science.gov (United States)

    Duffield, Rob; Portus, Marc

    2007-07-01

    To compare the effects of three types of full-body compression garments (Skins, Adidas and Under Armour) on repeat-sprint and throwing performance in cricket players. Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat-sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre-exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O(2) saturation and O(2) partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. No significant differences (p>0.05) were evident in repeat-sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p0.05). No benefit was noted when wearing compression garments for repeat-sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness.

  11. Throwing Injuries of the Shoulder.

    Science.gov (United States)

    McCue, Frank C., III; and Others

    The majority of shoulder injuries occurring in throwing sports involve the soft tissue structures. Injuries often occur when the unit is overstretched to a point near its greatest length, involving the elastic tissues. The other injury mechanism involves the contractural unit of the muscle, which occurs near the midpoint of contractions, involving…

  12. Kinematic Description of Elite Vs. Low Level Players in Team-Handball Jump Throw

    Science.gov (United States)

    Wagner, Herbert; Buchecker, Michael; von Duvillard, Serge P.; Müller, Erich

    2010-01-01

    The jump throw is the most applied throwing technique in team- handball (Wagner et al., 2008); however, a comprehensive analysis of 3D-kinematics of the team-handball jump throw is lacking. Therefore, the purpose of our study was: 1) to measure differences in ball release speed in team- handball jump throw and anthropometric parameters between groups of different levels of performance and (2) to analyze upper body 3D-kinematics (flexion/extension and rotation) to determine significant differences between these groups. Three-dimensional kinematic data was analyzed via the Vicon MX 13 motion capturing system (Vicon Peak, Oxford, UK) from 26 male team-handball players of different performance levels (mean age: 21.2 ± 5.0 years). The participants were instructed to throw the ball (IHF Size 3) onto a target at 8 m distance, and to hit the center of a square of 1 × 1 m at about eye level (1.75 m), with maximum ball release speed. Significant differences between elite vs. low level players were found in the ball release speed (p handball players who were taller and of greater body weight have the ability to achieve a higher ball release speed in the jump throw, and that an increase in trunk flexion and rotation angular velocity improve the performance in team-handball jump throw that should result in an increase of ball release speed. Key points Team-handball players who were taller and of greater body weight have the ability to achieve a higher ball release speed. An increase in trunk flexion, trunk rotation and shoulder internal rotation angular velocity should result in an increase of ball release speed. Trunk movements are normally well observable for experienced coaches, easy correctable and therefore practical to improve the performance in team-handball jump throw of low level players during training without using complex measurement devices. PMID:24149381

  13. Motion database of disguised and non-disguised team handball penalty throws by novice and expert performers

    Directory of Open Access Journals (Sweden)

    Fabian Helm

    2017-12-01

    Full Text Available This article describes the motion database for a large sample (n = 2400 of 7-m penalty throws in team handball that includes 1600 disguised throws. Throws were performed by both novice (n = 5 and expert (n = 5 penalty takers. The article reports the methods and materials used to capture the motion data. The database itself is accessible for download via JLU Web Server and provides all raw files in a three-dimensional motion data format (.c3d. Additional information is given on the marker placement of the penalty taker, goalkeeper, and ball together with details on the skill level and/or playing history of the expert group. The database was first used by Helm et al. (2017 [1] to investigate the kinematic patterns of disguised movements. Results of this analysis are reported and discussed in their article “Kinematic patterns underlying disguised movements: Spatial and temporal dissimilarity compared to genuine movement patterns” (doi:10.1016/j.humov.2017.05.010 [1]. Keywords: Motion capture data, Disguise, Expertise

  14. THE RELATIONS BETWEEN MORPHOLOGICAL SPACE AND THE ATHLETES’ JUMPING AND THROWING EVENTS RESULT

    Directory of Open Access Journals (Sweden)

    Igor Stanojević

    2014-12-01

    Full Text Available The sample included 200 primary school students in the region of Prokuplje, male, aged 13 and 14 years, who, in addition to regular physical education classes, were included in the sports clubs training activities. The variables sample included 13 anthropometric measures as a set of predictors and four specific-motor tests of jumping (high jump and long jump and throwing events (shot put and javelin, as well as a set of criteria. The aim of this research was to examine the relation of morphological characteristics with the jumping and throwing events results, with elementary school students as athletes. Determining the relations and influence between the morphological characteristics and the specific motor skills was obtained by applying the canonical-correlation and regression analysis. The research of canonical correlation analysis results showed that there are statistically significant interlinks between canonical factors of morphological dimension Can. 0.81% (p = .000 and the results of examinee’s specific-motor skills in a long running jump, running high jump, shot put and javelin. Regression analysis results show that the morphological dimensions have an important prediction of the results of examinee’s specific-motor skills.

  15. Comparison of trunk kinematics in trunk training exercises and throwing.

    Science.gov (United States)

    Stodden, David F; Campbell, Brian M; Moyer, Todd M

    2008-01-01

    Strength and conditioning professionals, as well as coaches, have emphasized the importance of training the trunk and the benefits it may have on sport performance and reducing the potential for injury. However, no data on the efficacy of trunk training support such claims. The purpose of this study was to examine the maximum differential trunk rotation and maximum angular velocities of the pelvis and upper torso of participants while they performed 4 trunk exercises (seated band rotations, cross-overs, medicine ball throws, and twisters) and compare these trunk exercise kinematics with the trunk kinematics demonstrated in actual throwing performance. Nine NCAA Division I baseball players participated in this study. Each participant's trunk kinematics was analyzed while he performed 5 repetitions of each exercise in both dominant and nondominant rotational directions. Results indicated maximum differentiated rotation in all 4 trunk exercises was similar to maximum differentiated rotation (approximately 50-60 degrees) demonstrated in throwing performance. Maximum angular velocities of the pelvis and upper torso in the trunk exercises were appreciably slower (approximately 50% or less) than the angular velocities demonstrated during throwing performance. Incorporating trunk training exercises that demonstrate sufficient trunk ranges of motion and velocities into a strength and conditioning program may help to increase ball velocity and/or decrease the risk injury.

  16. Effect of core stability training on throwing velocity in female handball players.

    Science.gov (United States)

    Saeterbakken, Atle H; van den Tillaar, Roland; Seiler, Stephen

    2011-03-01

    The purpose was to study the effect of a sling exercise training (SET)-based core stability program on maximal throwing velocity among female handball players. Twenty-four female high-school handball players (16.6 ± 0.3 years, 63 ± 6 kg, and 169 ± 7 cm) participated and were initially divided into a SET training group (n = 14) and a control group (CON, n = 10). Both groups performed their regular handball training for 6 weeks. In addition, twice a week, the SET group performed a progressive core stability-training program consisting of 6 unstable closed kinetic chain exercises. Maximal throwing velocity was measured before and after the training period using photocells. Maximal throwing velocity significantly increased 4.9% from 17.9 ± 0.5 to 18.8 ± 0.4 m·s in the SET group after the training period (p core stability training using unstable, closed kinetic chain movements can significantly improve maximal throwing velocity. A stronger and more stable lumbopelvic-hip complex may contribute to higher rotational velocity in multisegmental movements. Strength coaches can incorporate exercises exposing the joints for destabilization force during training in closed kinetic chain exercises. This may encourage an effective neuromuscular pattern and increase force production and can improve a highly specific performance task such as throwing.

  17. The observational analysis of performance in the handball ´s throwing of the Spanish promises selection

    Directory of Open Access Journals (Sweden)

    Pablo Blanco García

    2012-06-01

    Full Text Available This work has as objective to analyze the efficiency of the handball´s throwings. For it, there were analyzed five matches that the lower level spanish selection disputed in an european championship. This process was realized by an observational methodology, where were evaluated different parameters related to the handball´s throwing: the model of the throw, distance, position and opposition with regard to the variable goal-no goal. The results found that the variables distance and opposition have an influence in the throwing´s efficiency, so that training of these parameters must be taken into account in the game.Key Words: Observational methodology, Spanish selection, Handball, Throwing,  Efficiency.

  18. Effects of Strength vs. Ballistic-Power Training on Throwing Performance.

    Science.gov (United States)

    Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos

    2013-01-01

    The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters.

  19. Reliability and validity of a talent identification test battery for seated and standing Paralympic throws.

    Science.gov (United States)

    Spathis, Jemima Grace; Connick, Mark James; Beckman, Emma Maree; Newcombe, Peter Anthony; Tweedy, Sean Michael

    2015-01-01

    Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test-retest reliability. Talent identification test-retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland-Altman plots (Limits of Agreement). Spearman's correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean rs = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.

  20. Simulation and experimental research on line throwing rocket with flight

    OpenAIRE

    Wen-bin Gu; Ming Lu; Jian-qing Liu; Qin-xing Dong; Zhen-xiong Wang; Jiang-hai Chen

    2014-01-01

    The finite segment method is used to model the line throwing rocket system. A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system and the consideration of the forces acting on the system. The experiment designed according to the parameters of the dynamic model is made. The simulation and experiment results, such as range, velocity and flight time, are compared and analyzed. The simulation results are basicall...

  1. Analysis, fabrication, and field test of an advanced embedded throwing electromechanical sensing system

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhen; Zhang, Dan [Beijing JiaoTong University, Beijing (China)

    2014-01-15

    Scientific measuring equipment is important in maintaining and further improving the daily training quality of professional athletes. In throwing sports, only kinematic information is usually recorded by several high-speed cameras, whereas the dynamic data are lacking. An advanced embedded throwing system is analyzed, fabricated, and field tested. This throwing system can be used to substitute the normal shot-put that obtains acceleration information from the upper limb when force is applied onto the device. This device has four main parts, namely, a mechanical shell, an embedded sensor, a signal processing circuit, and interface ports. The detailed design, simulation, and prototyping process are introduced in this work. The practical results obtained from the field test and feedback from users prove that the proposed throwing system is efficient for technical training and monitoring. This design provides a unique solution for the modeling and development of non-traditional, electro-mechanical sensing devices.

  2. BASEBALL THROWING MECHANICS AS THEY RELATE TO PATHOLOGY AND PERFORMANCE - A REVIEW

    Directory of Open Access Journals (Sweden)

    Rod Whiteley

    2007-03-01

    Full Text Available It is a commonly held perception amongst biomechanists, sports medicine practitioners, baseball coaches and players, that an individual baseball player's style of throwing or pitching influences their performance and susceptibility to injury. With the results of a series of focus groups with baseball managers and pitching coaches in mind, the available scientific literature was reviewed regarding the contribution of individual aspects of pitching and throwing mechanics to potential for injury and performance. After a discussion of the limitations of kinematic and kinetic analyses, the individual aspects of pitching mechanics are discussed under arbitrary headings: Foot position at stride foot contact; Elbow flexion; Arm rotation; Arm horizontal abduction; Arm abduction; Lead knee position; Pelvic orientation; Deceleration-phase related issues; Curveballs; and Teaching throwing mechanics. In general, popular opinion of baseball coaching staff was found to be largely in concordance with the scientific investigations of biomechanists with several notable exceptions. Some difficulties are identified with the practical implementation of analyzing throwing mechanics in the field by pitching coaches, and with some unquantified aspects of scientific analyses

  3. Relationship of pectoralis major muscle size with bench press and bench throw performances.

    Science.gov (United States)

    Akagi, Ryota; Tohdoh, Yukihiro; Hirayama, Kuniaki; Kobayashi, Yuji

    2014-06-01

    This study examined the relationship of muscle size indices of the pectoralis major muscle with bench press and bench throw performances in 18 male collegiate athletes. The maximal cross-sectional area (MCSAMAx) and volume (MV) of the pectoralis major muscle were determined by magnetic resonance imaging. First, subjects were tested for their one repetition maximum bench press strength (1RMBP) using a Smith machine. At a later date, subjects performed bench throws using the Smith machine with several different loads ranging from 30.0 kg to 90% of 1RMBP. Barbell positions were measured by a linear position transducer, and bench throw power was calculated using a dynamic equation. Three trials were performed for each load. In all the trials, the maximal peak power was adopted as bench throw peak power (PPBT). The 1RMBP was significantly correlated with MCSAMAx. Similarly, the correlation coefficient between MV and PPBT was significant. In contrast to the y-intercept of the MV-PPBT regression line, that of the MCSAMAx-1RMBP regression line was not significantly different from 0. These results suggested that, although the dependence on pectoralis major muscle size is slightly different between bench press strength and bench throw power, the pectoralis major muscle size has a significant impact on bench press and throw performances. Greater muscle size leads to heavier body weight, which can be a negative factor in some sports. We therefore recommend that athletes and their coaches develop training programs for improving sports performance by balancing the advantage of increased muscle size and the potential disadvantage of increased body weight.

  4. Relationship between throwing velocity, muscle power, and bar velocity during bench press in elite handball players.

    Science.gov (United States)

    Marques, Mario C; van den Tilaar, Roland; Vescovi, Jason D; Gonzalez-Badillo, Juan Jose

    2007-12-01

    The purpose of this study was to examine the relationship between ball-throwing velocity during a 3-step running throw and dynamic strength, power, and bar velocity during a concentric-only bench-press exercise in team-handball players. Fourteen elite senior male team-handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric-only bench-press test with 26, 36, and 46 kg, as well as having 1-repetition-maximum (1-RMBP) strength determined. Ball-throwing velocity was evaluated with a standard 3-step running throw using a radar gun. Ball-throwing velocity was related to the absolute load lifted during the 1-RMBP (r = .637, P = .014), peak power using 36 kg (r = .586, P = .028) and 46 kg (r = .582, P = .029), and peak bar velocity using 26 kg (r = .563, P = .036) and 36 kg (r = .625, P = .017). The results indicate that throwing velocity of elite team-handball players is related to maximal dynamic strength, peak power, and peak bar velocity. Thus, a training regimen designed to improve ball-throwing velocity in elite male team-handball players should include exercises that are aimed at increasing both strength and power in the upper body.

  5. Design and Implementation of an Embedded Digital Throwing System Based on MEMS Multiaxial Accelerometer

    Directory of Open Access Journals (Sweden)

    Zhen GAO

    2010-04-01

    Full Text Available This paper presents a novel embedded digital throwing system for synchronously sensing the throwing force of shot-put athletes in real time. The three axes integrated accelerometer, as a crucial device in the force sensing system, can acquire the kinetics data along three orthogonal directions with reasonably high accuracy. The digital shot with almost the same size and weight as the standard shot for open female has been designed, fabricated and implemented. The mechanical structure, signal processing system, and human-machine interface are illuminated in detail. In this manner, the force sensing system serves as a powerful tool for coaches and sports scientists to make scientific researches on professional throwing techniques. It also provides an intuitive and reliable guidance for the throwing athletes to improve their skills.

  6. Effect of Core Training on Male Handball Players’ Throwing Velocity

    OpenAIRE

    Manchado, Carmen; García-Ruiz, José; Cortell-Tormo, Juan M.; Tortosa Martínez, Juan

    2017-01-01

    Abstract In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ? 3.4 years, body height 179.3 ? 7.0 cm, body mass 78.9 ? 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control g...

  7. Frequent Immediate Knowledge of Results Enhances the Increase of Throwing Velocity in Overarm Handball Performance.

    Science.gov (United States)

    Štirn, Igor; Carruthers, Jamie; Šibila, Marko; Pori, Primož

    2017-02-01

    In the present study, the effect of frequent, immediate, augmented feedback on the increase of throwing velocity was investigated. An increase of throwing velocity of a handball set shot when knowledge of results was provided or not provided during training was compared. Fifty female and seventy-three male physical education students were assigned randomly to the experimental or control group. All participants performed two series of ten set shots with maximal effort twice a week for six weeks. The experimental group received information regarding throwing velocity measured by a radar gun immediately after every shot, whereas the control group did not receive any feedback. Measurements of maximal throwing velocity of an ordinary handball and a heavy ball were performed, before and after the training period and compared. Participants who received feedback on results attained almost a four times greater relative increase of the velocity of the normal ball (size 2) as compared to the same intervention when feedback was not provided (8.1 ± 3.6 vs. 2.7 ± 2.9%). The velocity increases were smaller, but still significant between the groups for throws using the heavy ball (5.1 ± 4.2 and 2.5 ± 5.8 for the experimental and control group, respectively). Apart from the experimental group throwing the normal ball, no differences in velocity change for gender were obtained. The results confirmed that training oriented towards an increase in throwing velocity became significantly more effective when frequent knowledge of results was provided.

  8. Sequence-dependent rotation axis changes and interaction torque use in overarm throwing.

    Science.gov (United States)

    Hansen, Clint; Rezzoug, Nasser; Gorce, Philippe; Venture, Gentiane; Isableu, Brice

    2016-01-01

    We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal-external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder-centre of mass axis and the shoulder-elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs' rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder-elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release.

  9. A universal throw model and its applications

    NARCIS (Netherlands)

    Voort, M.M. van der; Doormaal, J.C.A.M. van; Verolme, E.K.; Weerheijm, J.

    2008-01-01

    A deterministic model has been developed that describes the throw of debris or fragments from a source with an arbitrary geometry and for arbitrary initial conditions. The initial conditions are defined by the distributions of mass, launch velocity and launch direction. The item density in an

  10. Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

    Science.gov (United States)

    Monezi, Lucas Antônio; Magalhães, Thiago Pinguelli; Morato, Márcio Pereira; Mercadante, Luciano Allegretti; Furtado, Otávio Luis Piva da Cunha; Misuta, Milton Shoiti

    2018-03-26

    In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

  11. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c) One...

  12. Characterization of blade throw from a 2.3MW horizontal axis wind turbine upon failure

    DEFF Research Database (Denmark)

    Sarlak, Hamid; Sørensen, Jens Nørkær

    2015-01-01

    The present work concerns aerodynamics of thrown objects from a 2.3 MW Horizontal Axis Wind Turbine (HAWT), as a consequence of blade failure. The governing set of ordinary differential equations for the flying objects are derived and numerically solved using a 4th order Runge-Kutta time advancing...... on their size. Thereafter, throw distance picks up exponentially with the tip speed. By comparing the throw distance calculations with and without dynamic stall model being active, it is concluded that dynamic stall does not play a major role in throw distances....

  13. INCIDENCIA DE LOS TIROS LIBRES EN PARTIDOS DE BALONCESTO PROFESIONAL [Incidence of free throws in professional basketball games

    Directory of Open Access Journals (Sweden)

    José Vicente García Tormo

    2015-04-01

    The aim of this study is to describe the incident of the free throw on the final results of the basketball match, and see how other factors may influence the final average of successful free throws, comparing national leagues with European competition. A total of 59,364 free throws have been analyzed, corresponding to 1722 matches from two seasons of the Spanish professional basketball league (ACB and LFB and European league (Euroleague Euroleague and women. Has been made descriptive analysis, an analysis of synchrony and an analysis of the residuals corrected. The results demonstrate the importance of free throws for the final score, especially in male and when is a close match. Likewise, the home court advantage is related to higher efficiency in free throws and win the match.

  14. How to Throw a Bird?

    DEFF Research Database (Denmark)

    Zakaria, Anne Lassen; Bruun, Charlotte

    been left behind in global economic development, it is important to recognise that interventions, such as within tourism, cannot start on a tabula rasa. Hence, in this paper we argue that geographical locations are living systems where different stakeholders, formal and informal institutions......, environment with its wildlife, etc., all interact and influence interventions and outcomes. In metaphorical terms developing locations through tourism is like attempting to make a bird fly in a desired direction: One can never predict completely the direction in which it will fly. On the contrary throwing...

  15. CAN UPPER EXTREMITY FUNCTIONAL TESTS PREDICT THE SOFTBALL THROW FOR DISTANCE: A PREDICTIVE VALIDITY INVESTIGATION

    Science.gov (United States)

    Hanney, William J.; Kolber, Morey J.; Davies, George J.; Riemann, Bryan

    2011-01-01

    Introduction: Understanding the relationships between performance tests and sport activity is important to the rehabilitation specialist. The purpose of this study was two- fold: 1) To identify if relationships exist between tests of upper body strength and power (Single Arm Seated Shot Put, Timed Push-Up, Timed Modified Pull-Up, and The Davies Closed Kinetic Chain Upper Extremity Stability Test, and the softball throw for distance), 2) To determine which variable or group of variables best predicts the performance of a sport specific task (the softball throw for distance). Methods: One hundred eighty subjects (111 females and 69 males, aged 18-45 years) performed the 5 upper extremity tests. The Pearson product moment correlation and a stepwise regression were used to determine whether relationships existed between performance on the tests and which upper extremity test result best explained the performance on the softball throw for distance. Results: There were significant correlations (r=.33 to r=.70, p=0.001) between performance on all of the tests. The modified pull-up test was the best predictor of the performance on the softball throw for distance (r2= 48.7), explaining 48.7% of variation in performance. When weight, height, and age were added to the regression equation the r2 values increased to 64.5, 66.2, and 67.5 respectively. Conclusion: The results of this study indicate that several upper extremity tests demonstrate significant relationships with one another and with the softball throw for distance. The modified pull up test was the best predictor of performance on the softball throw for distance. PMID:21712942

  16. Closed-kinetic chain upper-body training improves throwing performance of NCAA Division I softball players.

    Science.gov (United States)

    Prokopy, Max P; Ingersoll, Christopher D; Nordenschild, Edwin; Katch, Frank I; Gaesser, Glenn A; Weltman, Arthur

    2008-11-01

    Closed-kinetic chain resistance training (CKCRT) of the lower body is superior to open-kinetic chain resistance training (OKCRT) to improve performance parameters (e.g., vertical jump), but the effects of upper-body CKCRT on throwing performance remain unknown. This study compared shoulder strength, power, and throwing velocity changes in athletes training the upper body exclusively with either CKCRT (using a system of ropes and slings) or OKCRT. Fourteen female National Collegiate Athletic Association Division I softball player volunteers were blocked and randomly placed into two groups: CKCRT and OKCRT. Blocking ensured the same number of veteran players and rookies in each training group. Training occurred three times weekly for 12 weeks during the team's supervised off-season program. Olympic, lower-body, core training, and upper-body intensity and volume in OKCRT and CKCRT were equalized between groups. Criterion variables pre- and posttraining included throwing velocity, bench press one-repetition maximum (1RM), dynamic single-leg balance, and isokinetic peak torque and power (PWR) (at 180 degrees x s(-1)) for shoulder flexion, extension, internal rotation, and external rotation (ER). The CKCRT group significantly improved throwing velocity by 2.0 mph (3.4%, p performance. Strength coaches can incorporate upper-body CKCRT without sacrificing gains in maximal strength or performance criteria associated with an athletic open-chain movement such as throwing.

  17. Communication: importance sampling including path correlation in semiclassical initial value representation calculations for time correlation functions.

    Science.gov (United States)

    Pan, Feng; Tao, Guohua

    2013-03-07

    Full semiclassical (SC) initial value representation (IVR) for time correlation functions involves a double phase space average over a set of two phase points, each of which evolves along a classical path. Conventionally, the two initial phase points are sampled independently for all degrees of freedom (DOF) in the Monte Carlo procedure. Here, we present an efficient importance sampling scheme by including the path correlation between the two initial phase points for the bath DOF, which greatly improves the performance of the SC-IVR calculations for large molecular systems. Satisfactory convergence in the study of quantum coherence in vibrational relaxation has been achieved for a benchmark system-bath model with up to 21 DOF.

  18. Water polo throwing velocity and kinematics: differences between competitive levels in male players.

    Science.gov (United States)

    Melchiorri, G; Viero, V; Triossi, T; De Sanctis, D; Padua, E; Salvati, A; Galvani, C; Bonifazi, M; Del Bianco, R; Tancredi, V

    2015-11-01

    In water polo, throwing is one of the most important and frequently used technical skills for the player. There is no scientific literature that provides information about differences in throwing between elite and sub-elite water polo players. The aim of our study was to study differences in throwing velocities and kinematic variables in elite and sub-elite level male water polo players. We considered the variables under standardized conditions during a typical motion, the five-meter shot (penalty). Thirty-four athletes from the Men's First Division Water Polo Championship and forty-two players participating in the National Fourth Division League, took part in the study. Video analysis measures were taken with high-speed digital cameras and the videos were analyzed offline with Dartfish 5.0 Pro. No correlation was found between body mass, height and throwing velocity. Elite players had higher values ​for ball speed (22.8±2.4 m/s for elite team and 18.4±1.7 m/s for sub-elite team; P=0.002) and greater elbow angle (157.5±10.3 degree for elite team versus 146.7±8.9 degree for sub-elite team; P=0.002). In elite team the throwing time was lower (165.6±22.2 and 188.6±23.9 ms, respectively; P=0.05) and the shoulder angle was smaller (115.1±10.3 and 123.8±12.4 degree, respectively; P=0.03) than in sub-elite team. Head height was significantly greater in elite players (elite players 71.1±8.7 cm, sub-elite players 65.6±6.2 cm; P=0.03). Differences in kinematic characteristics between elite and sub-elite players were showed. Differences in elbow and shoulder action must be considered both in training and injury prevention.

  19. Biomechanics of increased spin velocity of flying discs during forehand throws by skilled and unskilled throwers.

    Science.gov (United States)

    Sasakawa, Kei; Umegaki, Koji; Sakurai, Shinji

    2018-04-01

    We aimed to assess the relationship between throwing distance and kinematic release parameters of the flying disc in unskilled throwers, and to assess the relationship between kinetic variables acting on flying discs and the change in spin velocity during long forehand throws by skilled and unskilled throwers. Ten skilled and eleven unskilled throwers performed throws at maximum effort. Reflective marker positions on the disc and body were recorded with a 3D motion capture system during the throws to derive kinematic variables of a disc and kinetic variables acting on the disc. The analysis interval was from maximum external shoulder rotation to disc release. Significant correlations were observed between the throwing distance and spin velocity in skilled (r = 0.722, P < 0.05) and unskilled throwers (r = 0.794, P < 0.01), between the change in spin velocity and the angular impulse of moments of force, in unskilled throwers (r = 0.703, P < 0.05), and between the change in spin velocity and the angular impulse of torque among skilled throwers (r = 0.680, P < 0.01). Therefore, a strategy for increasing spin velocity in unskilled throwers could be used to generate a larger torque, similar to that observed in skilled throwers.

  20. Perceptual training effects on anticipation of direct and deceptive 7-m throws in handball.

    Science.gov (United States)

    Alsharji, Khaled E; Wade, Michael G

    2016-01-01

    We examined the effectiveness of perceptual training on the performance of handball goalkeepers when anticipating the direction of both direct and deceptive 7-m throws. Skilled goalkeepers were assigned equally to three matched-ability groups based on their pre-test performance: a perceptual training group (n = 14) received video-based perceptual training, a placebo training group (n = 14) received video-based regular training and a control group received no training. Participants in the perceptual training group significantly improved their performance compared to both placebo and control groups; however, anticipation of deceptive throws improved less than for direct throws. The results confirm that although anticipating deception in handball is a challenging task for goalkeepers, task-specific perceptual training can minimise its effect and improve performance.

  1. An open-chain imaginary-time path-integral sampling approach to the calculation of approximate symmetrized quantum time correlation functions

    Science.gov (United States)

    Cendagorta, Joseph R.; Bačić, Zlatko; Tuckerman, Mark E.

    2018-03-01

    We introduce a scheme for approximating quantum time correlation functions numerically within the Feynman path integral formulation. Starting with the symmetrized version of the correlation function expressed as a discretized path integral, we introduce a change of integration variables often used in the derivation of trajectory-based semiclassical methods. In particular, we transform to sum and difference variables between forward and backward complex-time propagation paths. Once the transformation is performed, the potential energy is expanded in powers of the difference variables, which allows us to perform the integrals over these variables analytically. The manner in which this procedure is carried out results in an open-chain path integral (in the remaining sum variables) with a modified potential that is evaluated using imaginary-time path-integral sampling rather than requiring the generation of a large ensemble of trajectories. Consequently, any number of path integral sampling schemes can be employed to compute the remaining path integral, including Monte Carlo, path-integral molecular dynamics, or enhanced path-integral molecular dynamics. We believe that this approach constitutes a different perspective in semiclassical-type approximations to quantum time correlation functions. Importantly, we argue that our approximation can be systematically improved within a cumulant expansion formalism. We test this approximation on a set of one-dimensional problems that are commonly used to benchmark approximate quantum dynamical schemes. We show that the method is at least as accurate as the popular ring-polymer molecular dynamics technique and linearized semiclassical initial value representation for correlation functions of linear operators in most of these examples and improves the accuracy of correlation functions of nonlinear operators.

  2. An open-chain imaginary-time path-integral sampling approach to the calculation of approximate symmetrized quantum time correlation functions.

    Science.gov (United States)

    Cendagorta, Joseph R; Bačić, Zlatko; Tuckerman, Mark E

    2018-03-14

    We introduce a scheme for approximating quantum time correlation functions numerically within the Feynman path integral formulation. Starting with the symmetrized version of the correlation function expressed as a discretized path integral, we introduce a change of integration variables often used in the derivation of trajectory-based semiclassical methods. In particular, we transform to sum and difference variables between forward and backward complex-time propagation paths. Once the transformation is performed, the potential energy is expanded in powers of the difference variables, which allows us to perform the integrals over these variables analytically. The manner in which this procedure is carried out results in an open-chain path integral (in the remaining sum variables) with a modified potential that is evaluated using imaginary-time path-integral sampling rather than requiring the generation of a large ensemble of trajectories. Consequently, any number of path integral sampling schemes can be employed to compute the remaining path integral, including Monte Carlo, path-integral molecular dynamics, or enhanced path-integral molecular dynamics. We believe that this approach constitutes a different perspective in semiclassical-type approximations to quantum time correlation functions. Importantly, we argue that our approximation can be systematically improved within a cumulant expansion formalism. We test this approximation on a set of one-dimensional problems that are commonly used to benchmark approximate quantum dynamical schemes. We show that the method is at least as accurate as the popular ring-polymer molecular dynamics technique and linearized semiclassical initial value representation for correlation functions of linear operators in most of these examples and improves the accuracy of correlation functions of nonlinear operators.

  3. Kinematical Comparison Analysis on the Discus Athletes Throwing Techniques Based on Data Project

    Science.gov (United States)

    Junming, Li; Jihe, Zhou; Ting, Long

    2017-09-01

    In the discus final site of throwing event series game of China’s track and field sport in April, 2015, three dimensional camera analytical method which is an application of kinematical data project was used on female discus athletes’ discus throwing technology. And analysis was made for the top four discus throwers’ last exertion action, related kinematics parameter was thus obtained. Analysis results show that: first, Lu Xiaoxin behaves better in body twist tight effect when it is left foot on the ground and in capacity of beyond devices, followed by Su Xinyue and Tan Jian, with Feng Bin relatively weaker; second, our athletes’ discus shots speed is to be upgraded compared with world excellent female discus athletes; third, discus is left slightly earlier, with Tan Jian throwing in a reasonable angle, Feng Bin, Lu Xiaoxin in a larger angle, and Sue Xinyue in a smaller angle. Feng bin has a higher height of release, followed by Lu Xiaoxin and Tan jian.

  4. Water evaporation: a transition path sampling study.

    Science.gov (United States)

    Varilly, Patrick; Chandler, David

    2013-02-07

    We use transition path sampling to study evaporation in the SPC/E model of liquid water. On the basis of thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.

  5. Accuracy of Skill Performance in the Basketball Free Throw Shooting

    Directory of Open Access Journals (Sweden)

    Igawa Shoji

    2011-12-01

    Full Text Available The purpose of this study were to investigates how timing of shot of skilled player and assess performance accuracy of free throw shooting. Ten college students participated in this study (5 skilled players, and 5 naïve participants aged 18-23 years. They performed free throw shooting at 10 times. Shooting seen was recorded three cameras and analyzed shooting successful rate, off-target distance (the distance between the basketball through point and the center of the goal and shot timing. Shot timing was not significant difference. Shooting successful rate of skilled players was higher than unskilled players. Offtarget distance of skilled players was significant smaller than naive player. Consequently, skilled player is possible to aim at the center of the goal and shooting near the center of goal.

  6. Infrastructure Development: Public Private Partnership Path for Developing Rural Telecommunications in Africa

    Directory of Open Access Journals (Sweden)

    Idongesit William Williams

    2012-06-01

    Full Text Available It is the quest of every government to achieve universal Access and service of telecommunication services and ICTs. Unfortunately due to the high cost of deploying infrastructure in rural areas of developing countries due to non-significant or no economic activity, this dream of achieving Universal access and service of telecommunications/ICTs have been stalled. This paper throws light on a possible Public Private Partnership framework as a development path that will enable affordable network technologies to be deployed in rural areas at a cost that will translate to what the rural dweller in a developing country in Africa can afford. The paper is a conceptual paper

  7. A New Learning Control System for Basketball Free Throws Based on Real Time Video Image Processing and Biofeedback

    Directory of Open Access Journals (Sweden)

    R. Sarang

    2018-02-01

    Full Text Available Shooting free throws plays an important role in basketball. The major problem in performing a correct free throw seems to be inappropriate training. Training is performed offline and it is often not that persistent. The aim of this paper is to consciously modify and control the free throw using biofeedback. Elbow and shoulder dynamics are calculated by an image processing technique equipped with a video image acquisition system. The proposed setup in this paper, named learning control system, is able to quantify and provide feedback of the above parameters in real time as audio signals. Therefore, it yielded to performing a correct learning and conscious control of shooting. Experimental results showed improvements in the free throw shooting style including shot pocket and locked position. The mean values of elbow and shoulder angles were controlled approximately on 89o and 26o, for shot pocket and also these angles were tuned approximately on 180o and 47o respectively for the locked position (closed to the desired pattern of the free throw based on valid FIBA references. Not only the mean values enhanced but also the standard deviations of these angles decreased meaningfully, which shows shooting style convergence and uniformity. Also, in training conditions, the average percentage of making successful free throws increased from about 64% to even 87% after using this setup and in competition conditions the average percentage of successful free throws enhanced about 20%, although using the learning control system may not be the only reason for these outcomes. The proposed system is easy to use, inexpensive, portable and real time applicable.

  8. The effectiveness of snow cube throwing learning model based on exploration

    Science.gov (United States)

    Sari, Nenden Mutiara

    2017-08-01

    This study aimed to know the effectiveness of Snow Cube Throwing (SCT) and Cooperative Model in Exploration-Based Math Learning in terms of the time required to complete the teaching materials and student engagement. This study was quasi-experimental research was conducted at SMPN 5 Cimahi, Indonesia. All student in grade VIII SMPN 5 Cimahi which consists of 382 students is used as population. The sample consists of two classes which had been chosen randomly with purposive sampling. First experiment class consists of 38 students and the second experiment class consists of 38 students. Observation sheet was used to observe the time required to complete the teaching materials and record the number of students involved in each meeting. The data obtained was analyzed by independent sample-t test and used the chart. The results of this study: SCT learning model based on exploration are more effective than cooperative learning models based on exploration in terms of the time required to complete teaching materials based on exploration and student engagement.

  9. Heating and thermal control of brazing technique to break contamination path for potential Mars sample return

    Science.gov (United States)

    Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Campos, Sergio

    2017-04-01

    The potential return of Mars sample material is of great interest to the planetary science community, as it would enable extensive analysis of samples with highly sensitive laboratory instruments. It is important to make sure such a mission concept would not bring any living microbes, which may possibly exist on Mars, back to Earth's environment. In order to ensure the isolation of Mars microbes from Earth's Atmosphere, a brazing sealing and sterilizing technique was proposed to break the Mars-to-Earth contamination path. Effectively, heating the brazing zone in high vacuum space and controlling the sample temperature for integrity are key challenges to the implementation of this technique. The break-thechain procedures for container configurations, which are being considered, were simulated by multi-physics finite element models. Different heating methods including induction and resistive/radiation were evaluated. The temperature profiles of Martian samples in a proposed container structure were predicted. The results show that the sealing and sterilizing process can be controlled such that the samples temperature is maintained below the level that may cause damage, and that the brazing technique is a feasible approach to breaking the contamination path.

  10. Throw in the i-Drone

    Directory of Open Access Journals (Sweden)

    Bram Entrop

    2015-08-01

    Full Text Available Although many consider drones to be toys, multiple industries, such as the agriculture and mining industry, already know what advantages professional Unmanned Aerial Vehicles (UAVs can offer. However, many companies in the construction industry do not seem to be familiar yet with the possible advantages of UAVs for their projects. In our 3TU Lighthouse project “Throw in the I-drone” we, the University of Twente, Delft University of Technology, and BeemFlights, would like to make the construction industry aware of the possibilities UAVs have by demonstrating possible usages, by providing a protocol on how to use them and by simplifying the interpretation of data collected.

  11. Adaptive enhanced sampling with a path-variable for the simulation of protein folding and aggregation

    Science.gov (United States)

    Peter, Emanuel K.

    2017-12-01

    In this article, we present a novel adaptive enhanced sampling molecular dynamics (MD) method for the accelerated simulation of protein folding and aggregation. We introduce a path-variable L based on the un-biased momenta p and displacements dq for the definition of the bias s applied to the system and derive 3 algorithms: general adaptive bias MD, adaptive path-sampling, and a hybrid method which combines the first 2 methodologies. Through the analysis of the correlations between the bias and the un-biased gradient in the system, we find that the hybrid methodology leads to an improved force correlation and acceleration in the sampling of the phase space. We apply our method on SPC/E water, where we find a conservation of the average water structure. We then use our method to sample dialanine and the folding of TrpCage, where we find a good agreement with simulation data reported in the literature. Finally, we apply our methodologies on the initial stages of aggregation of a hexamer of Alzheimer's amyloid β fragment 25-35 (Aβ 25-35) and find that transitions within the hexameric aggregate are dominated by entropic barriers, while we speculate that especially the conformation entropy plays a major role in the formation of the fibril as a rate limiting factor.

  12. Bio-mechanical assessment toward throwing and lifting process of i-LOCA (Innovative Lobster Catcher)

    Science.gov (United States)

    Sudiarno, A.; Dewi, D. S.; Putri, M. A.

    2018-04-01

    Indonesia is the country rich in marine resource, one of which is lobster. East java, one of Indonesian province, especially in Region of Gresik and Lamogan, has very huge potential of lobster. Current condition shown that lobster catch by the fisherman mostly depend on lucky factor, which the lobster unintentionally trapped in fisherman’s fish net. By using this mechanism, the number of lobster catch cannot be optimum. Previous researches have produced two versions of i-LOCA, Innovative Lobster Catcher, a special tool for catching the lobster. Although produce more lobster catch, second version of i-LOCA still needs to be scrutinized, one of that is bio-mechanical assessment. The second version of i-LOCA still has no tool to ease throwing and lifting it into the sea. This condition cause Musculoskeletal Disorder (MSD) toward the fisherman. This research perform bio-mechanical assessment toward throwing and lifting process in order to suggest improvement for i-LOCA as the third version. Based on body moment calculation, we found that throwing and lifting process of third version of i-LOCA, each was 3 times and 2 times better than second version of i-LOCA. Meanwhile, Rapid Entire Body Assessment (REBA) score of throwing and lifting process for third version of i-LOCA can be reduced by 5 points compared to second version of i-LOCA.

  13. Prevalence of Human Papillomavirus Infection in Unselected SurePath Samples Using the APTIMA HPV mRNA Assay

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Preisler, Sarah; Ejegod, Ditte M

    2013-01-01

    The APTIMA Human Papillomavirus (HPV) Assay detects E6/E7 mRNA from 14 human papillomavirus genotypes. Horizon was a population-based split-sample study among well-screened women, with an aim to compare APTIMA, Hybrid Capture 2 (HC2), and liquid-based cytology (LBC) using SurePath samples. APTIMA...

  14. THE LEVEL AND AGE DYNAMICS OF SPORTS ACHIEVEMENTS OF ATHLETES-VETERANS OF THE HAMMER THROW

    Directory of Open Access Journals (Sweden)

    Ivanova Natalya Dmitrievna

    2013-03-01

    Full Text Available The article presents the records of the world and Russian athletes veterans in the hammer throw, starting with the age group 35-39 years and up to age group 100-104 years, and a comparison of the records of veterans subject to an age factor and of the high scores of athletes in the current sports. The aim of the work is to analyze the level and dynamics of the records of the world and Russian athletes, veterans in the hammer throw in each five-year group starting with the age group 35-39 years and up to age group 100-104 years. The novelty of the work consists in comparison of the records of the world and Russia in the hammer throw active athletes and records of veterans with the amendment to the age factor. Analysis of the level and age dynamics of sports achievements of domestic and foreign athletes-throwers older age groups. In the course of the research it is established, that in the throwing hammer, decreasing absolute (without regard to the age factor results, which is largely due to the natural age-related changes in the organism of athletes. Records of the world athletes-veterans compared with the records of active athletes and the transition from each of the five-year group in the following, decline on average in men by 10,0%, among women by 19,3%, in spite of the fact that the weight of the shells in the hammer throw with age decreases. Presented the reasons for the backwardness of Russian athletes older than 35 years of foreign veterans.

  15. Throwing-related injuries of the subscapularis in professional baseball players

    Energy Technology Data Exchange (ETDEWEB)

    Polster, Joshua M.; Ilaslan, Hakan; Subhas, Naveen [Cleveland Clinic, Imaging Institute, Cleveland, OH (United States); Lynch, T.S. [Columbia University Medical Center, Center for Shoulder, Elbow and Sports Medicine, New York, NY (United States); Bullen, Jennifer A. [Cleveland Clinic, Quantitative Health Sciences, Cleveland, OH (United States); Soloff, Lonnie [Cleveland Indians, Cleveland, OH (United States); Schickendantz, Mark S. [Cleveland Clinic, Orthopedic and Rheumatologic Institute, Cleveland, OH (United States)

    2016-01-15

    To describe the MR appearance of a series of throwing-related injuries to the subscapularis muscle-tendon complex among baseball players. A retrospective review of MR scans of the shoulder in players from 1 professional baseball organization over the course of 5 years was performed to identify cases with findings suggestive of subscapularis injury. These findings were graded and the medical record was reviewed to assess clinical findings, treatment, and follow-up. Preinjury baseline measurements of arm external rotation at 90 of abduction were compared to measurements from a noninjured cohort to evaluate whether this measure is a risk factor for injury. A total of 133 MR scans of the shoulder were evaluated. Eleven of the scans demonstrated signal changes suggesting subscapularis injury; 10 of these 11 patients had clinical findings supporting a diagnosis of throwing-related subscapularis strain. There were four grade 1, four grade 2, and two grade 3 injuries. All injuries occurred in the inferior half of the subscapularis at the myotendinous junction. Risk of subscapularis injury increased with lower levels of dominant arm external rotation (odds ratio, 1.12; 95 % CI, 1.07-1.21; p < 0.001). A threshold of dominant arm external rotation of <106 demonstrated sensitivity of 0.700 (95 % CI, 0.392-0.897) and specificity of 0.951 (95 % CI, 0.888-0.982) for subscapularis injury. Throwing-related subscapularis injuries occur in the inferior half of the muscle at the myotendinous junction. Our data suggest that there is an increased risk of these injuries with lower levels of dominant arm external rotation. (orig.)

  16. Age and gender differences in adolescent and adult overarm throwing.

    Science.gov (United States)

    Lorson, Kevin M; Stodden, David F; Langendorfer, Stephen J; Goodway, Jacqueline D

    2013-06-01

    The purposes of this study were to examine age and gender differences in throwing performance across an underexplored portion of the lifespan: middle adolescents (14-17 years old), young adults (18-25 years old), and adults (35-55 years old). Throwing performance was assessed using the body component levels from Roberton's developmental sequences for force and ball velocity that were recorded by a radar gun. Participants in each age group performed between 5 to 10 forceful overhand throws toward a target approximately 15m to 20m from the thrower. A Wilcoxon-Mann-Whitney Test was used to determine gender differences and a Wilcoxon-Signed Ranks Test was used to determine age-group differences for each component. Gender and age-group differences in ball speed were determined by a 3 (age group) x 2 (gender) factorial analysis of variance with follow-up post-hoc tests. Young-adult men had higher body component levels and ball speed compared with the adolescent boys and adult men. Female age-group differences existed only for humerus action between young-adult and adult groups and for ball speed between young-adult and adolescent groups. Gender differences (p < .01) existed in component levels for the adolescent and young-adult groups, but not the adult groups. Gender differences in ball speed (p < .001) existed within each age group. Although these data were cross-sectional, the regressive developmental changes observed and the narrowing gender gap may eventually provide insight related to the relationships among motor skill competence, physical fitness, and physical activity across the lifespan.

  17. Throwing-related injuries of the subscapularis in professional baseball players

    International Nuclear Information System (INIS)

    Polster, Joshua M.; Ilaslan, Hakan; Subhas, Naveen; Lynch, T.S.; Bullen, Jennifer A.; Soloff, Lonnie; Schickendantz, Mark S.

    2016-01-01

    To describe the MR appearance of a series of throwing-related injuries to the subscapularis muscle-tendon complex among baseball players. A retrospective review of MR scans of the shoulder in players from 1 professional baseball organization over the course of 5 years was performed to identify cases with findings suggestive of subscapularis injury. These findings were graded and the medical record was reviewed to assess clinical findings, treatment, and follow-up. Preinjury baseline measurements of arm external rotation at 90 of abduction were compared to measurements from a noninjured cohort to evaluate whether this measure is a risk factor for injury. A total of 133 MR scans of the shoulder were evaluated. Eleven of the scans demonstrated signal changes suggesting subscapularis injury; 10 of these 11 patients had clinical findings supporting a diagnosis of throwing-related subscapularis strain. There were four grade 1, four grade 2, and two grade 3 injuries. All injuries occurred in the inferior half of the subscapularis at the myotendinous junction. Risk of subscapularis injury increased with lower levels of dominant arm external rotation (odds ratio, 1.12; 95 % CI, 1.07-1.21; p < 0.001). A threshold of dominant arm external rotation of <106 demonstrated sensitivity of 0.700 (95 % CI, 0.392-0.897) and specificity of 0.951 (95 % CI, 0.888-0.982) for subscapularis injury. Throwing-related subscapularis injuries occur in the inferior half of the muscle at the myotendinous junction. Our data suggest that there is an increased risk of these injuries with lower levels of dominant arm external rotation. (orig.)

  18. Increasing Free Throw Accuracy through Behavior Modeling and Goal Setting.

    Science.gov (United States)

    Erffmeyer, Elizabeth S.

    A two-year behavior-modeling training program focusing on attention processes, retention processes, motor reproduction, and motivation processes was implemented to increase the accuracy of free throw shooting for a varsity intercollegiate women's basketball team. The training included specific learning keys, progressive relaxation, mental…

  19. The relationship between gluteal muscle activation and throwing kinematics in baseball and softball catchers.

    Science.gov (United States)

    Plummer, Hillary A; Oliver, Gretchen D

    2014-01-01

    The purpose of this study was to determine the relationship between gluteal muscle activation and pelvis and trunk kinematics when catchers throw to second base. Forty-two baseball and softball catchers (14.74 ± 4.07 years; 161.85 ± 15.24 cm; 63.38 ± 19.98 kg) participated in this study. Muscle activity of the bilateral gluteus maximus and medius as well as pelvis and trunk kinematics throughout the throwing motion were analyzed. It was discovered that at foot contact, there were 2 significant inverse relationships between stride leg gluteus maximus activity and pelvis axial rotation (r = -0.31, r2 = 0.10, p = 0.05), and between trunk axial rotation and pelvis lateral flexion (r = -0.34, r2= 0.12, p = 0.03). In addition, at foot contact, a significant positive relationship between the drive leg (throwing arm side) and trunk flexion (r = 0.33, r2 = 0.11, p = 0.04) was present. The results of this study provide evidence of gluteal activation both concentrically and eccentrically, in attempt to control the pelvis and trunk during the throwing motion of catchers. The gluteal muscles play a direct role in maintaining the stability of the pelvis, and catchers should incorporate strengthening of the entire lumbopelvic-hip complex into their training regimen. Incorporating concentric and eccentric gluteal exercises will help to improve musculoskeletal core stability, thereby assisting in upper extremity injury prevention.

  20. Effects of Variable Resistance Using Chains on Bench Throw Performance in Trained Rugby Players.

    Science.gov (United States)

    Godwin, Mark S; Fernandes, John F T; Twist, Craig

    2018-04-01

    Godwin, MS, Fernandes, JFT, and Twist, C. Effects of variable resistance using chains on bench throw performance in trained rugby players. J Strength Cond Res 32(4): 950-954, 2018-This study sought to determine the effects of variable resistance using chain resistance on bench throw performance. Eight male rugby union players (19.4 ± 2.3 years, 88.8 ± 6.0 kg, 1RM 105.6 ± 17.0 kg) were recruited from a national league team. In a randomized crossover design, participant's performed 3 bench throws at 45% one repetition maximum (1RM) at a constant load (no chains) or a variable load (30% 1RM constant load and 15% 1RM variable load; chains) with 7 days between conditions. For each repetition, the peak and mean velocity, peak power, peak acceleration, and time to peak velocity were recorded. Differences in peak and mean power were very likely trivial and unclear between the chain and no chain conditions, respectively. Possibly greater peak and likely greater mean bar velocity were accompanied by likely to most likely greater bar velocity between 50 and 400 ms from initiation of bench press in the chain condition compared with the no chain condition. Accordingly, bar acceleration was very likely greater in the chain condition compared with the no chain condition. In conclusion, these results show that the inclusion of chain resistance can acutely enhance several variables in the bench press throw and gives support to this type of training.

  1. Judgement bias in predicting the success of one’s own basketball free throws but not those of others

    NARCIS (Netherlands)

    Canal Bruland, R.; Balch, L.; Niesert, L.

    2015-01-01

    Skilled basketball players are supposed to hit more often from the free throw distance than would be predicted by their shooting performances at adjacent distances. This is dubbed an especial skill. In the current study, we examined whether especial skills in free throw performance in basketball map

  2. Associations between rate of force development metrics and throwing velocity in elite team handball players: a short research report.

    Science.gov (United States)

    Marques, Mário C; Saavedra, Francisco J; Abrantes, Catarina; Aidar, Felipe J

    2011-09-01

    Performance assessment has become an invaluable component of monitoring participant's development in distinct sports, yet limited and contradictory data are available in trained subjects. The purpose of this study was to examine the relationship between ball throwing velocity during a 3-step running throw in elite team handball players and selected measures of rate of force development like force, power, velocity, and bar displacement during a concentric only bench press exercise in elite male handball players. Fitteen elite senior male team handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric only bench press test with 25, 35, and 45 kg as well as having one-repetition maximum strength determined. Ball throwing velocity was evaluated with a standard 3-step running throw using a radar gun. The results of this study indicated significant associations between ball velocity and time at maximum rate of force development (0, 66; pvelocity was only median associated with maximum rate of force development with light loads. A training regimen designed to improve ball-throwing velocity in elite male team handball players should emphasize bench press movement using light loads.

  3. Sample-Path Optimal Stationary Policies in Stable Markov Decision Chains with Average Reward Criterion

    Czech Academy of Sciences Publication Activity Database

    Cavazos-Cadena, R.; Montes-de-Oca, R.; Sladký, Karel

    2015-01-01

    Roč. 52, č. 2 (2015), s. 419-440 ISSN 0021-9002 Grant - others:GA AV ČR(CZ) 171396 Institutional support: RVO:67985556 Keywords : Dominated Convergence theorem for the expected average criterion * Discrepancy function * Kolmogorov inequality * Innovations * Strong sample-path optimality Subject RIV: BC - Control Systems Theory Impact factor: 0.665, year: 2015 http://library.utia.cas.cz/separaty/2015/E/sladky-0449029.pdf

  4. Quantitative assessment of developmental levels in overarm throwing using wearable inertial sensing technology.

    Science.gov (United States)

    Grimpampi, Eleni; Masci, Ilaria; Pesce, Caterina; Vannozzi, Giuseppe

    2016-09-01

    Motor proficiency in childhood has been recently recognised as a public health determinant, having a potential impact on the physical activity level and possible sedentary behaviour of the child later in life. Among fundamental motor skills, ballistic skills assessment based on in-field quantitative observations is progressively needed in the motor development community. The aim of this study was to propose an in-field quantitative approach to identify different developmental levels in overarm throwing. Fifty-eight children aged 5-10 years performed an overarm throwing task while wearing three inertial sensors located at the wrist, trunk and pelvis level and were then categorised using a developmental sequence of overarm throwing. A set of biomechanical parameters were defined and analysed using multivariate statistics to evaluate whether they can be used as developmental indicators. Trunk and pelvis angular velocities and time durations before the ball release showed increasing/decreasing trends with increasing developmental level. Significant differences between developmental level pairs were observed for selected biomechanical parameters. The results support the suitability and feasibility of objective developmental measures in ecological learning contexts, suggesting their potential supportiveness to motor learning experiences in educational and youth sports training settings.

  5. Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines

    DEFF Research Database (Denmark)

    Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

    2012-01-01

    It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

  6. Simultaneous determination of sample thickness, tilt, and electron mean free path using tomographic tilt images based on Beer-Lambert law.

    Science.gov (United States)

    Yan, Rui; Edwards, Thomas J; Pankratz, Logan M; Kuhn, Richard J; Lanman, Jason K; Liu, Jun; Jiang, Wen

    2015-11-01

    Cryo-electron tomography (cryo-ET) is an emerging technique that can elucidate the architecture of macromolecular complexes and cellular ultrastructure in a near-native state. Some important sample parameters, such as thickness and tilt, are needed for 3-D reconstruction. However, these parameters can currently only be determined using trial 3-D reconstructions. Accurate electron mean free path plays a significant role in modeling image formation process essential for simulation of electron microscopy images and model-based iterative 3-D reconstruction methods; however, their values are voltage and sample dependent and have only been experimentally measured for a limited number of sample conditions. Here, we report a computational method, tomoThickness, based on the Beer-Lambert law, to simultaneously determine the sample thickness, tilt and electron inelastic mean free path by solving an overdetermined nonlinear least square optimization problem utilizing the strong constraints of tilt relationships. The method has been extensively tested with both stained and cryo datasets. The fitted electron mean free paths are consistent with reported experimental measurements. The accurate thickness estimation eliminates the need for a generous assignment of Z-dimension size of the tomogram. Interestingly, we have also found that nearly all samples are a few degrees tilted relative to the electron beam. Compensation of the intrinsic sample tilt can result in horizontal structure and reduced Z-dimension of tomograms. Our fast, pre-reconstruction method can thus provide important sample parameters that can help improve performance of tomographic reconstruction of a wide range of samples. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Ulnohumeral chondral and ligamentous overload: biomechanical correlation for posteromedial chondromalacia of the elbow in throwing athletes.

    Science.gov (United States)

    Osbahr, Daryl C; Dines, Joshua S; Breazeale, Nathan M; Deng, Xiang-Hua; Altchek, David W

    2010-12-01

    Previous studies have documented increased posteromedial contact forces with the elbow at lower flexion angles associated with valgus extension overload; however, the authors believe that posteromedial elbow impingement in association with valgus laxity is a complex pathological process that may occur throughout the entire throwing motion in the form of ulnohumeral chondral and ligamentous overload. Valgus laxity with the elbow at 90° of flexion may lead to chondromalacia secondary to a subtle shift in the contact point between the tip of the olecranon and the distal humeral trochlea. Controlled laboratory study. Six fresh human cadaveric elbows were dissected and subjected to a static valgus load. Pressure-sensitive Fuji film measured the contact pressure, contact area, and shift in contact area across the posteromedial elbow before and after sectioning the anterior bundle of the ulnar collateral ligament. The contact pressure between the tip of the olecranon process and the medial crista of the posterior humeral trochlea significantly increased, from an average of 0.27 ± 0.06 kg/cm² to 0.40 ± 0.08 kg/cm². The contact area also significantly decreased, from an average of 30.34 ± 9.17 mm² to 24.59 ± 6.44 mm², and shifted medially on the medial humeral crista, which corresponds to the position of the posteromedial chondral lesions that was observed in throwing athletes in the authors' clinical practice. While simulating the early acceleration phase of the throwing motion with the elbow in 90° of flexion, the results illustrate that abnormal contact may occur as a result of valgus laxity through increased contact pressures across the posteromedial elbow between the medial tip of the olecranon and medial crista of the humeral trochlea. In addition, congruency of the ulnohumeral joint changed, as there was a statistically significant medial shift of the olecranon on the posterior humeral trochlea with the elbow at 90° of flexion after sectioning the anterior

  8. Differences in anthropometric characteristics in relation to throwing velocity and competitive level in professional male team handball: a tool for talent profiling.

    Science.gov (United States)

    Fieseler, Georg; Hermassi, Souhail; Hoffmeyer, Birgit; Schulze, Stephan; Irlenbusch, Lars; Bartels, Thomas; Delank, Karl-Stefan; Laudner, Kevin G; Schwesig, René

    2017-01-01

    The primary aim of the study was to examine the anthropometric characteristics as well as throwing and sprinting performance of professional handball players classified by playing position and competition level. 21 male players (age: 25.2±5.1 years) from the first German handball league (FGL) and 34 male players (age: 26.1±4.1 years) from the third German handball league (TGL) were categorized as backs, pivots, wings and goalkeepers. Measurements included anthropometric data (height, mass and body mass index (BMI)), throwing and sprinting performance selected out of a complex handball test (HBCT), which was conducted twice (2 rounds). During the HBCT, the subjects performed two sprints (10, 20 m), two standing throws with run-up (ST) and four vertical jump throws (VJT) over a hurdle (20 cm) with and without precision for goal shot. The anthropometric data revealed a significantly (P=0.038 and η2=0.079) shorter body height for TGL than for FGL players. In the cohort of first league athletes the pivots were the tallest (1.98±0.04 m), backs in the third league showed the maximum body height (1.90±0.05 m). Regarding body mass, pivots were the heaviest players independent from the league membership. The FGL players showed a significantly (P0.10) higher throwing velocity in all type of throws. Body height was significantly related to ST (r=0.53) and VJT (r=0.52) in the first round of HBCT but only for the FGL athletes. Throwing velocity was also correlated with BMI (r=-0.50) among the TGL players. Substantial differences of body characteristics, throwing and sprinting performance between playing positions and competitive levels underline the importance of a careful scouting and position-specific training for professional handball players.

  9. Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

    Directory of Open Access Journals (Sweden)

    Rafael Sabido

    Full Text Available To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players.Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kgwere divided into two groups (unknown loads: UL; known loads: KL. Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM. In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press, power output (with 30, 50 and 70% of 1RM and throwing velocity (7 m standing throw and 9 m jumping throw were assessed pre- and post-training intervention.Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms with the three loads (30, 50, 70% 1RM in the UL group, while KL only improved with 30% 1RM (all the time intervals and with 70% 1RM (at certain time intervals. Only the UL group improved throwing velocity in both standing (4.7% and jumping (5.3% throw (p > 0.05.The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

  10. Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

    Science.gov (United States)

    Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

    2016-01-01

    To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

  11. Unknown loads affect force production capacity in early phases of bench press throws.

    Science.gov (United States)

    Hernández Davó, J L; Sabido Solana, R; Sarabia Marínm, J M; Sánchez Martos, Á; Moya Ramón, M

    2015-10-01

    Explosive strength training aims to improve force generation in early phases of movement due to its importance in sport performance. The present study examined the influence of lack of knowledge about the load lifted in explosive parameters during bench press throws. Thirteen healthy young men (22.8±2.0 years) participated in the study. Participants performed bench press throws with three different loads (30, 50 and 70% of 1 repetition maximum) in two different conditions (known and unknown loads). In unknown condition, loads were changed within sets in each repetition and participants did not know the load, whereas in known condition the load did not change within sets and participants had knowledge about the load lifted. Results of repeated-measures ANOVA revealed that unknown conditions involves higher power in the first 30, 50, 100 and 150 ms with the three loads, higher values of ratio of force development in those first instants, and differences in time to reach maximal rate of force development with 50 and 70% of 1 repetition maximum. This study showed that unknown conditions elicit higher values of explosive parameters in early phases of bench press throws, thereby this kind of methodology could be considered in explosive strength training.

  12. Automated Prediction of Catalytic Mechanism and Rate Law Using Graph-Based Reaction Path Sampling.

    Science.gov (United States)

    Habershon, Scott

    2016-04-12

    In a recent article [ J. Chem. Phys. 2015 , 143 , 094106 ], we introduced a novel graph-based sampling scheme which can be used to generate chemical reaction paths in many-atom systems in an efficient and highly automated manner. The main goal of this work is to demonstrate how this approach, when combined with direct kinetic modeling, can be used to determine the mechanism and phenomenological rate law of a complex catalytic cycle, namely cobalt-catalyzed hydroformylation of ethene. Our graph-based sampling scheme generates 31 unique chemical products and 32 unique chemical reaction pathways; these sampled structures and reaction paths enable automated construction of a kinetic network model of the catalytic system when combined with density functional theory (DFT) calculations of free energies and resultant transition-state theory rate constants. Direct simulations of this kinetic network across a range of initial reactant concentrations enables determination of both the reaction mechanism and the associated rate law in an automated fashion, without the need for either presupposing a mechanism or making steady-state approximations in kinetic analysis. Most importantly, we find that the reaction mechanism which emerges from these simulations is exactly that originally proposed by Heck and Breslow; furthermore, the simulated rate law is also consistent with previous experimental and computational studies, exhibiting a complex dependence on carbon monoxide pressure. While the inherent errors of using DFT simulations to model chemical reactivity limit the quantitative accuracy of our calculated rates, this work confirms that our automated simulation strategy enables direct analysis of catalytic mechanisms from first principles.

  13. Optical design of ultrashort throw liquid crystal on silicon projection system

    Science.gov (United States)

    Huang, Jiun-Woei

    2017-05-01

    An ultrashort throw liquid crystal on silicon (LCoS) projector for home cinema, virtual reality, and automobile heads-up display has been designed and fabricated. To achieve the best performance and highest-quality image, this study aimed to design wide-angle projection optics and optimize the illumination for LCoS. Based on the telecentric lens projection system and optimized Koehler illumination, the optical parameters were calculated. The projector's optical system consisted of a conic aspheric mirror and image optics using either symmetric double Gauss or a large-angle eyepiece to achieve a full projection angle larger than 155 deg. By applying Koehler illumination, image resolution was enhanced and the modulation transfer function of the image in high spatial frequency was increased to form a high-quality illuminated image. The partial coherence analysis verified that the design was capable of 2.5 lps/mm within a 2 m×1.5 m projected image. The throw ratio was less than 0.25 in HD format.

  14. Influence of a sport-specific training background on vertical jumping and throwing performance in young female basketball and volleyball players.

    Science.gov (United States)

    Battaglia, G; Paoli, A; Bellafiore, M; Bianco, A; Palma, A

    2014-10-01

    The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. Thirty-one healthy adolescent girls, of which 11 age-matched control subjects [C], 10 basketballers (BP) and 10 volleyballers (VP) participated to the study. The throwing performance was assessed by seated backward overhead ball throw (SBOMBT) and seated chest pass throw (SCPT) using a 3-kg rubber medicine ball. Instead, the vertical jumping performance was evaluated by squat jump (SJ) and countermovement jump with (CMJ-AS) and without arm swing (CMJ) using Optojump system (Microgate srl, Italy). During SJ and CMJ with and without arm swing VP group showed a higher vertical jump performance than BP and C ones. In particular we showed that VP exhibited a higher flight time and jump height than C (Pbasketball athletes' maximal power compared to age-matched control subjects.

  15. Effectiveness of the attack and the throw of the first four teams in the Men's Handball Games ODESUR 2014

    Directory of Open Access Journals (Sweden)

    Andrés González Ramírez

    2016-07-01

    Full Text Available The aim of this research was to analyse the attack actions effectiveness for the first four teams qualified for male team Handball during South American Games 2014 (ODESUR and to compare them with de main international tournaments (Olympics games, World and European Championships. No previous records of this kind of studies had been found in this particular competition of the Olympics classification round. Patterns of observational methodology were followed. Results showed that in ODESUR games, differences between winners and losers where observed in the number of attack endings with throws and ball loses. No meaningful differences where showed in effectiveness throwing. The effectiveness attack and throwing levels were less than in other elite tournaments

  16. Changes in Muscle Architecture, Explosive Ability, and Track and Field Throwing Performance Throughout a Competitive Season and After a Taper.

    Science.gov (United States)

    Bazyler, Caleb D; Mizuguchi, Satoshi; Harrison, Alex P; Sato, Kimitake; Kavanaugh, Ashley A; DeWeese, Brad H; Stone, Michael H

    2017-10-01

    The purpose of this study was to examine the effects of an overreach and taper on measures of muscle architecture, jumping, and throwing performance in Division I collegiate throwers preparing for conference championships. Six collegiate track and field throwers (3 hammer, 2 discus, 1 javelin) trained for 12 weeks using a block-periodization model culminating with a 1-week overreach followed by a 3-week taper (ORT). Session rating of perceived exertion training load (RPETL) and strength training volume-load times bar displacement (VLd) were recorded weekly. Athletes were tested pre-ORT and post-ORT on measures of vastus lateralis architecture, unloaded and loaded squat and countermovement jump performance, underhand and overhead throwing performance, and competition throwing performance. There was a statistical reduction in weight training VLd/session (d = 1.21, p ≤ 0.05) and RPETL/session (d = 0.9, p ≤ 0.05) between the in-season and ORT training phases. Five of 6 athletes improved overhead throw and competition throwing performance after the ORT (d = 0.50, p ≤ 0.05). Vastus lateralis muscle thickness statistically increased after the in-season training phase (d = 0.28, p ≤ 0.05) but did not change after the ORT. Unloaded countermovement jump peak force and relative peak power improved significantly after the ORT (d = 0.59, p ≤ 0.05, d = 0.31, p ≤ 0.05, respectively). These findings demonstrate that an overreaching week followed by a 3-week taper is an effective means of improving explosive ability and throwing performance in collegiate track and field throwers despite the absence of detectable changes in muscle architecture.

  17. performance routines followed by free throw shooting accuracy in secondary basketball players

    Directory of Open Access Journals (Sweden)

    Phelps Ashley

    2015-12-01

    Full Text Available Study aim: The purpose of the current study was to determine whether existing pre-performance routines had an effect on free throw shooting accuracy in high school pupils as compared to shooting without a pre-performance routine.

  18. Differences in physical fitness and throwing velocity among elite and amateur male handball players.

    Science.gov (United States)

    Gorostiaga, E M; Granados, C; Ibáñez, J; Izquierdo, M

    2005-04-01

    This study compared physical characteristics (body height, body mass [BM], body fat [BF], and free fatty mass [FFM]), one repetition maximum bench-press (1RM (BP)), jumping explosive strength (VJ), handball throwing velocity, power-load relationship of the leg and arm extensor muscles, 5- and 15-m sprint running time, and running endurance in two handball male teams: elite team, one of the world's leading teams (EM, n = 15) and amateur team, playing in the Spanish National Second Division (AM, n = 15). EM had similar values in body height, BF, VJ, 5- and 15-m sprint running time and running endurance than AM. However, the EM group gave higher values in BM (95.2 +/- 13 kg vs. 82.4 +/- 10 kg, p vs. 72.4 +/- 7 kg, p vs. 83 +/- 10 kg, p vs. 21.8 +/- 1.6 m . s (-1), p vs. 22.9 +/- 1.4 m . s (-1), p individual values of velocity at 30 % of 1RM (BP) and individual values of ball velocity during a standing throw. Significant correlations were observed in EM, but not in AM, between the individual values of velocity during 3-step running throw and the individual values of velocity at 30 % of 1RM (BP) (r = 0.72, p individual values of power at 100 % of body mass during half-squat actions (r = 0.62, p < 0.05). The present results suggest that more muscular and powerful players are at an advantage in handball. The differences observed in free fatty mass could partly explain the differences observed between groups in absolute maximal strength and muscle power. In EM, higher efficiency in handball throwing velocity may be associated with both upper and lower extremity power output capabilities, whereas in AM this relationship may be different. Endurance capacity does not seem to represent a limitation for elite performance in handball.

  19. Predictive Ability of the Medicine Ball Chest Throw and Vertical Jump Tests for Determining Muscular Strength and Power in Adolescents

    Science.gov (United States)

    Hackett, Daniel A.; Davies, Timothy B.; Ibel, Denis; Cobley, Stephen; Sanders, Ross

    2018-01-01

    This study examined the predictive ability of the medicine ball chest throw and vertical jump for muscular strength and power in adolescents. One hundred and ninety adolescents participated in this study. Participants performed trials of the medicine ball chest throw and vertical jump, with vertical jump peak power calculated via an estimation…

  20. Stride length: the impact on propulsion and bracing ground reaction force in overhand throwing.

    Science.gov (United States)

    Ramsey, Dan K; Crotin, Ryan L

    2018-03-26

    Propulsion and bracing ground reaction force (GRF) in overhand throwing are integral in propagating joint reaction kinetics and ball velocity, yet how stride length effects drive (hind) and stride (lead) leg GRF profiles remain unknown. Using a randomised crossover design, 19 pitchers (15 collegiate and 4 high school) were assigned to throw 2 simulated 80-pitch games at ±25% of their desired stride length. An integrated motion capture system with two force plates and radar gun tracked each throw. Vertical and anterior-posterior GRF was normalised then impulse was derived. Paired t-tests identified whether differences between conditions were significant. Late in single leg support, peak propulsion GRF was statistically greater for the drive leg with increased stride. Stride leg peak vertical GRF in braking occurred before acceleration with longer strides, but near ball release with shorter strides. Greater posterior shear GRF involving both legs demonstrated increased braking with longer strides. Conversely, decreased drive leg propulsion reduced both legs' braking effects with shorter strides. Results suggest an interconnection between normalised stride length and GRF application in propulsion and bracing. This work has shown stride length to be an important kinematic factor affecting the magnitude and timing of external forces acting upon the body.

  1. Effects of a shoot training programme with a reduced hoop diameter rim on free-throw performance and kinematics in young basketball players.

    Science.gov (United States)

    Khlifa, Riadh; Aouadi, Ridha; Shephard, Roy; Chelly, Mohamed Souhaiel; Hermassi, Souhail; Gabbett, Tim J

    2013-01-01

    The present paper investigated the effects of a shoot training programme with a reduced hoop diameter (0.35 m) rim on kinematics and performance of basketball free-throws. Eighteen young male basketball players were divided into control (CG, n = 9) and experimental (EG, n = 9) groups. Both groups undertook a 10-week training programme comprising two training sessions per week. Under fatigued conditions, each participant shot 150 free-throws in each training session, with the CG using a standard rim, and the EG a smaller rim. All other training was identical between groups. Ball release parameters, player's kinematics and mean of successful free-throws (out of 150 attempts) were determined for each participant, before and after completion of the training programme. Following training, a significant increase (P training with a reduced rim significantly improves free-throw performance in young basketball players.

  2. The Influence of the ‘Trier Social Stress Test’ on Free Throw Performance in Basketball: An Interdisciplinary Study

    Science.gov (United States)

    Mascret, Nicolas; Ibáñez-Gijón, Jorge; Bréjard, Vincent; Buekers, Martinus; Casanova, Rémy; Marqueste, Tanguy; Montagne, Gilles; Rao, Guillaume; Roux, Yannick; Cury, François

    2016-01-01

    The aim of the present study was to explore the relationship between stress and sport performance in a controlled setting. The experimental protocol used to induce stress in a basketball free throw was the Trier Social Stress Test (TSST) and its control condition (Placebo-TSST). Participants (n = 19), novice basketball players but trained sportspersons, were exposed to two counterbalanced conditions in a crossover design. They were equipped with sensors to measure movement execution, while salivary cortisol and psychological state were also measured. The task consisted of two sequences of 40 free throws, one before either the TSST or Placebo-TSST and one after. Physiological and psychological measures evidenced that the TSST induced significant stress responses, whereas the Placebo-TSST did not. Shooting performance remained stable after the TSST but decreased after the Placebo-TSST. We found no effect of the TSST or Placebo-TSST on movement execution. A multivariate model of free throw performance demonstrated that timing, smoothness and explosiveness of the movements are more relevant to account for beginner’s behavior than stress-related physiological and psychological states. We conclude that the TSST is a suitable protocol to induce stress responses in sport context, even though the effects on beginners’ free throw performance and execution are small and complex. PMID:27309715

  3. Chondromalacia of the trochlear notch in athletes who throw.

    Science.gov (United States)

    Robla, J; Hechtman, K S; Uribe, J W; Phillipon, M S

    1996-01-01

    Six athletes who throw and one shot-putter who underwent elbow arthroscopy were found to have an area of chondromalacia involving the posterolateral aspect of the olecranon. Preoperative symptoms were pain and tenderness to palpation over the lateral edge of the olecranon. On physical examination, range of motion was full or only slightly decreased (chondromalacia has not been previously described and, in our study, occurred in individuals whose elbows were subjected to repetitive valgus stress with lateral compression.

  4. Detecting reactive islands using Lagrangian descriptors and the relevance to transition path sampling.

    Science.gov (United States)

    Patra, Sarbani; Keshavamurthy, Srihari

    2018-02-14

    It has been known for sometime now that isomerization reactions, classically, are mediated by phase space structures called reactive islands (RI). RIs provide one possible route to correct for the nonstatistical effects in the reaction dynamics. In this work, we map out the reactive islands for the two dimensional Müller-Brown model potential and show that the reactive islands are intimately linked to the issue of rare event sampling. In particular, we establish the sensitivity of the so called committor probabilities, useful quantities in the transition path sampling technique, to the hierarchical RI structures. Mapping out the RI structure for high dimensional systems, however, is a challenging task. Here, we show that the technique of Lagrangian descriptors is able to effectively identify the RI hierarchy in the model system. Based on our results, we suggest that the Lagrangian descriptors can be useful for detecting RIs in high dimensional systems.

  5. Path probability distribution of stochastic motion of non dissipative systems: a classical analog of Feynman factor of path integral

    International Nuclear Information System (INIS)

    Lin, T.L.; Wang, R.; Bi, W.P.; El Kaabouchi, A.; Pujos, C.; Calvayrac, F.; Wang, Q.A.

    2013-01-01

    We investigate, by numerical simulation, the path probability of non dissipative mechanical systems undergoing stochastic motion. The aim is to search for the relationship between this probability and the usual mechanical action. The model of simulation is a one-dimensional particle subject to conservative force and Gaussian random displacement. The probability that a sample path between two fixed points is taken is computed from the number of particles moving along this path, an output of the simulation, divided by the total number of particles arriving at the final point. It is found that the path probability decays exponentially with increasing action of the sample paths. The decay rate increases with decreasing randomness. This result supports the existence of a classical analog of the Feynman factor in the path integral formulation of quantum mechanics for Hamiltonian systems

  6. The effects of different focus of attention on throwing skills among ...

    African Journals Online (AJOL)

    The aim of this study was to examine the effects of external focus (EF) of attention compared to internal focus (IF) of attention instructions on throwing boules in a modified-petanque game among the ASD children. Ten ASD children aged from seven to 10 participated in this study. They were randomly divided into two groups ...

  7. PEMBELAJARANSNOWBALL THROWING DITINJAU DARIGAYA BELAJAR EKSTROVERT-INTROVERT

    Directory of Open Access Journals (Sweden)

    Sulaiman Sulaiman

    2018-02-01

    Full Text Available ABSTRACT: The purpose of this study was to determine the results of students 'mathematics learning through cooperative learning model Snowball Throwingin terms of students' learning styles. The population of this research is all class VIII SMP Negeri 1 Adiluwih totaling 285 students. The sample was 70 students consisting of 35 students to a class of 35 students for the experimental and control classes were obtained by technique. cluster random sampling. The instrument used was a questionnaire and student mathematics achievement test. Data analysis techniques used a party t-test and t-test two parties. Based on t-test calculation of the two parties to the student's learning style extrovert, shows thitung = 3.07 and ttable = 2.021 at significance level of 5% that thitung > ttabel (3.07> 2,021, then H0 is rejected and  H1 received. For the t-test of the parties to the student's learning style extrovert show thitung = 3.07and ttabel = 1.684 at significance level of 5% that thitung > ttabel (3.07> 1.684, then H0  is rejected and  H1 accepted. T-test calculation of the two parties to the student's learning style introvert show thitung = -0.87 and ttabel = -2.069 at a significance level of 5% that thitung > ttabel (-0.87> -2.069, then H0 is  rejected and  H1  accepted. For the t-test for students' learning styles  introvertshow thitung = -0.87 and ttable = 1.714 at significance level of 5% that  thitung < ttabel   (-0.87 <1.714, then H0 is   rejected and H1 accepted.Key words: Snowball Throwing,learning style,ekstrovert, extrovert

  8. Smith machine counterbalance system affects measures of maximal bench press throw performance.

    Science.gov (United States)

    Vingren, Jakob L; Buddhadev, Harsh H; Hill, David W

    2011-07-01

    Equipment with counterbalance weight systems is commonly used for the assessment of performance in explosive resistance exercise movements, but it is not known if such systems affect performance measures. The purpose of this study was to determine the effect of using a counterbalance weight system on measures of smith machine bench press throw performance. Ten men and 14 women (mean ± SD: age, 25 ± 4 years; height, 173 ± 10 cm; weight, 77.7 ± 18.3 kg) completed maximal smith machine bench press throws under 4 different conditions (2 × 2; counterbalance × load): with or without a counterbalance weight system and using 'light' or 'moderate' net barbell loads. Performance variables (peak force, peak velocity, and peak power) were measured using a linear accelerometer attached to the barbell. The counterbalance weight system resulted in significant (p velocity (light: -0.49 ± 0.10 m·s; moderate: -0.33 ± 0.07 m·s), and peak power (light: -220 ± 43 W; moderate: -143 ± 28 W) compared with no counterbalance system for both load conditions. Load condition did not affect absolute or percentage reductions from the counterbalance weight system for any variable. In conclusion, the use of a counterbalance weight system reduces accelerometer-based performance measures for the bench press throw exercise at light and moderate loads. This reduction in measures is likely because of an increase in the external resistance during the movement, which results in a discrepancy between the manually input and the actual value for external load. A counterbalance weight system should not be used when measuring performance in explosive resistance exercises with an accelerometer.

  9. Differences in ball speed and three-dimensional kinematics between male and female handball players during a standing throw with run-up.

    Science.gov (United States)

    Serrien, Ben; Clijsen, Ron; Blondeel, Jonathan; Goossens, Maggy; Baeyens, Jean-Pierre

    2015-01-01

    The purpose of this paper was to examine differences in ball release speed and throwing kinematics between male and female team-handball players in a standing throw with run-up. Other research has shown that this throwing type produces the highest ball release speeds and comparing groups with differences in ball release speed can suggest where this difference might come from. If throwing technique differs, perhaps gender-specific coordination- and strength-training guidelines are in order. Measurements of three-dimensional kinematics were performed with a seven-camera VICON motion capture system and subsequent joint angles and angular velocities calculations were executed in Mathcad. Data-analysis with Statistical Parametric Mapping allowed us to examine the entire time-series of every variable without having to reduce the data to certain scalar values such as minima/maxima extracted from the time-series. Statistical Parametric Mapping enabled us to detect several differences in the throwing kinematics (12 out of 20 variables had one or more differences somewhere during the motion). The results indicated two distinct strategies in generating and transferring momentum through the kinematic chain. Male team-handball players showed more activity in the transverse plane (pelvis and trunk rotation and shoulder horizontal abduction) whereas female team-handball players showed more activity in the sagital plane (trunk flexion). Also the arm cocking maneuver was quite different. The observed differences between male and female team handball players in the motions of pelvis, trunk and throwing arm can be important information for coaches to give feedback to athletes. Whether these differences contribute to the observed difference in ball release speed is at the present unclear and more research on the relation with anthropometric profile needs to be done. Kinematic differences might suggest gender-specific training guidelines in team-handball.

  10. Maximal power training induced different improvement in throwing velocity and muscle strength according to playing positions in elite male handball players.

    Science.gov (United States)

    Cherif, M; Chtourou, H; Souissi, N; Aouidet, A; Chamari, K

    2016-12-01

    This study was designed to assess the effect of strength and power training on throwing velocity and muscle strength in handball players according to their playing positions. Twenty-two male handball players were assigned to either an experimental group (n=11) or a control group (n=11) (age: 22.1 ± 3.0 years). They were asked to complete (i) the ball throwing velocity test and (ii) the one-repetition maximum (1-RM) tests for the half-back squat, the pull-over, the bench press, the developed neck, and the print exercises before and after 12 weeks of maximal power training. The training was designed to improve strength and power with an intensity of 85-95% of the 1RM. In addition to their usual routine handball training sessions, participants performed two sessions per week. During each session, they performed 3-5 sets of 3-8 repetitions with 3 min of rest in between. Then, they performed specific shots (i.e., 12 to 40). Ball-throwing velocity (p<0.001) was higher after the training period in rear line players (RL). The training programme resulted in an improvement of 1RM bench press (p<0.001), 1RM developed neck (p<0.001) and 1RM print (p<0.001) in both front line (FL) and RL. The control group showed a significant improvement only in ball-throwing velocity (p<0.01) and 1RM bench press (p<0.01) in RL. A significantly greater improvement was found in ball-throwing velocity (p<0.001), 1RM bench press (p<0.001), and 1RM half-back squat exercises in players of the central axis (CA) compared to the lateral axis (LA) (p<0.01). The power training programme induced significantly greater increases in ball-throwing velocity and muscle strength in FL than RL and in CA than LA axis players.

  11. A Counterexample on Sample-Path Optimality in Stable Markov Decision Chains with the Average Reward Criterion

    Czech Academy of Sciences Publication Activity Database

    Cavazos-Cadena, R.; Montes-de-Oca, R.; Sladký, Karel

    2014-01-01

    Roč. 163, č. 2 (2014), s. 674-684 ISSN 0022-3239 Grant - others:PSF Organization(US) 012/300/02; CONACYT (México) and ASCR (Czech Republic)(MX) 171396 Institutional support: RVO:67985556 Keywords : Strong sample-path optimality * Lyapunov function condition * Stationary policy * Expected average reward criterion Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.509, year: 2014 http://library.utia.cas.cz/separaty/2014/E/sladky-0432661.pdf

  12. Effect of Biodiesel of Spent Cooking Oil Addition at Diesel Fuel to Opacity and Gas Emission Throw Away of CO, CO2 and HC

    International Nuclear Information System (INIS)

    Setyadji, Moch; Endang Susiantini

    2007-01-01

    Investigation of biodiesel spent cooking oil addition effect at diesel fuel to opacity and gas emission throw away on various engine rotation speed has been done. The variables observed were fuel specific used i.e. pure diesel fuel, biodiesel mix 5% (B5), mix 10% (B10), mix 15% (B15), mix 20% (B20) and engine rotation speed. Gas emission throw away observed were CO, CO 2 , HC and opacity. Opacity and gas emission throwaway were observed by Opacity Sagem apparatus and gas analyzer. Result of experiment showed that biodiesel addition at diesel fuel was very decreasing opacity and gas emission throw away. The opacity lowest on B20, gas emission throw away lowest of CO on B10, CO 2 on B10 and HC on B20. (author)

  13. Throwing velocity and kinematics in elite male water polo players.

    Science.gov (United States)

    Melchiorri, G; Padua, E; Padulo, J; D'Ottavio, S; Campagna, S; Bonifazi, M

    2011-12-01

    Fifty-three members of the Italian Men Water Polo Team were filmed using two synchronized cameras, while they were shooting a goal. Considering the differences in body mass, height, training strategies and the technical-tactical features of the players, the aims of this study were to employ video-analysis techniques in order to investigate selected kinematic parameters in water polo throwing, and to provide comprehensive quantitative information on the throwing movement in relation to the different team player positions. Video analysis was used to estimate the elbow angle at release, the shoulder angle at follow through, the back and head height at ball release, trunk rotation angle and ball velocity at release. Ball release velocities ranged from 21.0 to 29.8 m/s (average value 25.3±1.4 m/s), for field players. Goal keepers show the lowest team values (average 21.7±0.3 m/s). Similar to previous study results, ball release was typically reached just prior to the elbow approaching full extension (151.6±3.6°), and the follow through shoulder angle was 143±5.9°. No significant statistical difference was recorded between injured and non-injured athletes. No positive association was demonstrated between physical characteristics (body mass and height) and ball velocity.

  14. Cervical cancer incidence after normal cytological sample in routine screening using SurePath, ThinPrep, and conventional cytology

    DEFF Research Database (Denmark)

    Rozemeijer, Kirsten; Naber, Steffie K; Penning, Corine

    2017-01-01

    of histo- and cytopathology in the Netherlands (PALGA), January 2000 to March 2013.Population Women with 5 924 474 normal screening samples (23 833 123 person years).Exposure Use of SurePath or ThinPrep versus conventional cytology as screening test.Main outcome measure 72 month cumulative incidence...

  15. Training Physical Education Students to Self-Regulate during Basketball Free Throw Practice

    Science.gov (United States)

    Cleary, Timothy J.; Zimmerman, Barry J.; Keating, Tedd

    2006-01-01

    The additive effects of self-regulation training in forethought, performance, and self-reflection phase processes on acquiring a novel motoric skill (i.e., basketball free throws) and self-reflective beliefs were studied with 50 college students. The results showed a positive linear trend between the number of self-regulatory phases, in which the…

  16. Meningkatkan Prestasi Belajar Siswa Kelas VIII.F SMP Negeri 33 Surabaya Pada Mata Pelajaran IPS Materi Pranata Sosial Dengan Model Pembelajaran Snowball Throwing

    Directory of Open Access Journals (Sweden)

    Mudjianingsih Mudjianingsih

    2017-01-01

                          Asks activities in social studies is an important part in carrying out the study, which asks activities serve to gather information from students, to confirm what was already known, and to bring attention to the aspect of the unknown. Based on observations in the classroom conditions VIII F SMP Negeri 33 Surabaya Surabaya are less enthusiastic in asking questions the need for action using the appropriate learning models, one model of learning that can improve student learning outcomes is learning models Snowball Throwing. In this research there are four research purposes, the fourth such purposes include: 1 To determine the application of learning models Snowball Throwing, 2 To determine activity students 3 To determine student learning outcomes, and 3 To know the constraints and solutions in applying learning models Snowball Throwing.                     This study was a classroom action research (PTK with a qualitative approach in the classroom VIII F SMP Negeri 33 Surabaya Surabaya, which amounted to 32 students. In the application of Snowball Throwing consisting of two cycles, each cycle consisting of the planning stage, the stage of action, observation and reflection stages. Data collection techniques interest asked in this study using observation sheet interest to ask, and for student learning outcomes using the test cycle I and II. Data analysis using data reduction, observation data, and drawing conclusions. The results of this study show that: 1 Application of Learning Model Throwing Snowball carried out with 2 cycles, with each cycle consisting of the planning phase, the implementation phase, observation and reflection phase, 2 Complete test results of students in the first cycle was 68.42% , to test cycle II completeness increased to 100%, completeness criteria in this second cycle in the category Very Good, 3 constraints experienced researchers, among others: the seriousness of the students

  17. Path integral methods for primordial density perturbations - sampling of constrained Gaussian random fields

    International Nuclear Information System (INIS)

    Bertschinger, E.

    1987-01-01

    Path integrals may be used to describe the statistical properties of a random field such as the primordial density perturbation field. In this framework the probability distribution is given for a Gaussian random field subjected to constraints such as the presence of a protovoid or supercluster at a specific location in the initial conditions. An algorithm has been constructed for generating samples of a constrained Gaussian random field on a lattice using Monte Carlo techniques. The method makes possible a systematic study of the density field around peaks or other constrained regions in the biased galaxy formation scenario, and it is effective for generating initial conditions for N-body simulations with rare objects in the computational volume. 21 references

  18. Learning Method and Its Influence on Nutrition Study Results Throwing the Ball

    Science.gov (United States)

    Samsudin; Nugraha, Bayu

    2015-01-01

    This study aimed to know the difference between playing and learning methods of exploratory learning methods to learning outcomes throwing the ball. In addition, this study also aimed to determine the effect of nutritional status of these two learning methods mentioned above. This research was conducted at SDN Cipinang Besar Selatan 16 Pagi East…

  19. High explosive characterization for the dice throw event

    Energy Technology Data Exchange (ETDEWEB)

    Helm, F.; Finger, M.; Hayes, B.; Lee, E.; Cheung, H.; Walton, J.

    1976-06-16

    An equation of state for detonation products was developed to describe the detonation of large charges of ammonium nitrate/fuel oil (ANFO). The equation of state will be used to predict air-blast and ground-motion effects in the Dice Throw Event. The explosive performance of ANFO is highly dependent on charge size. The equation developed from this work is applicable to heavily confined detonations 101.6 mm in diameter or larger. The equation of state is based on results from experiments in cylinders and hemispheres, and a large field test. The report contains a detailed discussion of the diagnostic and initiation techniques used in these experiments.

  20. Impulsive force on the head during performance of typical ukemi techniques following different judo throws.

    Science.gov (United States)

    Hashimoto, Toshihiko; Ishii, Takanori; Okada, Naoyuki; Itoh, Masahiro

    2015-01-01

    In this study, eight judo athletes who are major candidates for the Japan national team were recruited as participants. Kinematic analysis of exemplary ukemi techniques was carried out using two throws, o-soto-gari, a throw linked to frequent injury, and o-uchi-gari. The aim of this study was to kinematically quantify the timing patterns of exemplary ukemi techniques and to obtain kinematic information of the head, in a sequence of ukemi from the onset of the throw to the completion of ukemi. The results indicated that the vertical velocity with which the uke's head decelerated was reduced by increasing the body surface exposed to the collision with the tatami and by increasing the elapsed time. In particular, overall upper limb contact with the tatami is greatly associated with deceleration. In o-soto-gari, the impulsive force on the faller's head as the head reached the lowest point was 204.82 ± 19.95 kg m · s(-2) while in o-uchi-gari it was 118.46 ± 63.62 kg m · s(-2), z = -1.75, P = 0.08, and it did present a large-sized effect with r = 0.78. These findings indicate that the exemplary o-soto-gari as compared to o-uchi-gari is the technique that causes more significant damage to the uke's head.

  1. MinePath: Mining for Phenotype Differential Sub-paths in Molecular Pathways

    Science.gov (United States)

    Koumakis, Lefteris; Kartsaki, Evgenia; Chatzimina, Maria; Zervakis, Michalis; Vassou, Despoina; Marias, Kostas; Moustakis, Vassilis; Potamias, George

    2016-01-01

    Pathway analysis methodologies couple traditional gene expression analysis with knowledge encoded in established molecular pathway networks, offering a promising approach towards the biological interpretation of phenotype differentiating genes. Early pathway analysis methodologies, named as gene set analysis (GSA), view pathways just as plain lists of genes without taking into account either the underlying pathway network topology or the involved gene regulatory relations. These approaches, even if they achieve computational efficiency and simplicity, consider pathways that involve the same genes as equivalent in terms of their gene enrichment characteristics. Most recent pathway analysis approaches take into account the underlying gene regulatory relations by examining their consistency with gene expression profiles and computing a score for each profile. Even with this approach, assessing and scoring single-relations limits the ability to reveal key gene regulation mechanisms hidden in longer pathway sub-paths. We introduce MinePath, a pathway analysis methodology that addresses and overcomes the aforementioned problems. MinePath facilitates the decomposition of pathways into their constituent sub-paths. Decomposition leads to the transformation of single-relations to complex regulation sub-paths. Regulation sub-paths are then matched with gene expression sample profiles in order to evaluate their functional status and to assess phenotype differential power. Assessment of differential power supports the identification of the most discriminant profiles. In addition, MinePath assess the significance of the pathways as a whole, ranking them by their p-values. Comparison results with state-of-the-art pathway analysis systems are indicative for the soundness and reliability of the MinePath approach. In contrast with many pathway analysis tools, MinePath is a web-based system (www.minepath.org) offering dynamic and rich pathway visualization functionality, with the

  2. Path Planning with a Lazy Significant Edge Algorithm (LSEA

    Directory of Open Access Journals (Sweden)

    Joseph Polden

    2013-04-01

    Full Text Available Probabilistic methods have been proven to be effective for robotic path planning in a geometrically complex environment. In this paper, we propose a novel approach, which utilizes a specialized roadmap expansion phase, to improve lazy probabilistic path planning. This expansion phase analyses roadmap connectivity information to bias sampling towards objects in the workspace that have not yet been navigated by the robot. A new method to reduce the number of samples required to navigate narrow passages is also proposed and tested. Experimental results show that the new algorithm is more efficient than the traditional path planning methodologies. It was able to generate solutions for a variety of path planning problems faster, using fewer samples to arrive at a valid solution.

  3. Acute influence of the application of strength treatment based on the combinated contrast training method on precision and velocity in overarm handball throwing

    Directory of Open Access Journals (Sweden)

    Juan S. Gómez Navarrete

    2011-01-01

    Full Text Available Abstract Combination of strengh training methods has been shown as an effective way for strengh development. This is specially indicated for improving explosive strengh and power. Our study shows the influence of combined contrast improvement method on overarm throwing in handball. Treatment consisted on one session of combined contras method. 10 handball palyers and 13 non-players participated in this estudy. The instrumental was a gun radar to know velocity throws, a camera to digitalize the accuracy, and an isometric dynamometer for strenght data collection. Results show a significant decrease in peak of force values in players group. Another significant decrease was obsesrved on integral to peak force for both groups. There are significant positive relations between throwing velocity parameters related to weight and size with isometric peak of force. We concluded that isometric time/strengh curve is an usefull instrument to observe changes produced in the subjet's capacity of producing strengh during training. Keywords: Precision, velocity, overarm handball throwing, isometric test, combined contrast method

  4. Robust Adaptive Photon Tracing using Photon Path Visibility

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Jensen, Henrik Wann

    2011-01-01

    We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our...... algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling...... and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility...

  5. Rest Interval Required for Power Training With Power Load in the Bench Press Throw Exercise.

    Science.gov (United States)

    Hernández Davó, Jose L; Solana, Rafael Sabido; Sarabia Marín, Jose M; Fernández Fernández, Jaime; Moya Ramón, Manuel

    2016-05-01

    This study aimed to test the influence of various rest interval (RI) durations used between sets on power output performance and physiological and perceptual variables during a strength training session using 40% of the 1 repetition maximum (1RM) in the bench press throw exercise. Thirty-one college students (18 males and 13 females) took part in the study. The experimental protocol consists of 5 sets of 8 repetitions of the bench press throw exercise with a load representing 40% of 1RM. Subjects performed the experimental protocol on 3 different occasions, differing by the RI between sets (1, 2, or 3 minutes). During the sessions, power data (mean power and peak power), physiological (lactate concentration [La]) and perceptual (rating of perceived exertion) variables were measured. In addition, delayed onset muscular soreness was reported 24 and 48 hours after the training session. One-way repeated-measures analysis of variance showed that 1-minute RI entailed higher power decreases and greater increases in values of physiological and perceptual variables compared with both 2- and 3-minute RIs. Nevertheless, no differences were found between 2- and 3-minute RIs. Therefore, this study showed that, when training with 40% of 1RM in the bench press throw exercise, a 2-minute RI between sets can be enough to avoid significant decreases in power output. Consequently, training sessions' duration could be reduced without causing excessive fatigue, allowing additional time to focus on other conditioning priorities.

  6. Proceedings of the DICE THROW Symposium 21-23 June 1977. Volume 1

    Science.gov (United States)

    1977-07-01

    Engineering Research Facility. 27. BLAST TESTS OF EXPEDIENT SHELTERS IN THE DICE THROW EVENT- C.H. Kearny, Oak Ridge National Laboratory. 28...Agency, 1977. 10. Gaffney , E., Close-in Measurements of Airblast and Ground Shock, POR 6909, Defense Nuclear Aqency, 1977. 11. Meyer, J., Crater and...EXPEDIENT SHELTERS FIELDED BY THE OAK RIDGE NATIONAL LABORATORY; COMMAND CONTROL COMMUNICATIONS SYSTEMS FIELDED BY THE BALLISTIC RESEARCH LABORATORY AND

  7. Timing and Activation Intensity of Shoulder Muscles during Handball Penalty Throwing in Subjects with and without Shoulder Impingement

    Directory of Open Access Journals (Sweden)

    Zahra Zonnor

    2017-08-01

    Full Text Available Introduction: Shoulder injuries are common among athletes in sports that involve overhead throwing of the ball such as handball. The objectives of this study were to evaluate the timing and activation intensity of shoulder muscles during handball penalty throwing in individuals with shoulder pain and in control subjects. Materials and Methods: Using BTS FREE EMG 300 system with bipolar surface electrodes, the timing (onset and intensity of the activation of the shoulder muscles were measured including upper trapezius, anterior, middle and posterior deltoid, latissimus dorsi, pectoralis major, supraspinatus and triceps during penalty throwing. Multivariate analysis of variance (ANOVA was used for between group comparisons with the significance level P< 0.05. Results: The activation intensity of upper trapezius and latissimus dorsi muscles in the healthy individuals were about 50.74% and 43.42% higher than in patients. Middle deltoid in healthy individuals was about 38.05% smaller than that in patients. In control group, supraspinatus muscle started earlier (23.5 ms than the shoulder motion initiation. Triceps muscle was activated about 18.5 ms later than shoulder motion initiation. In patients, supraspinatus muscle started sooner (11 ms and triceps brachialis muscle started later than the other muscles (22.16 ms. Conclusion: The coordination of shoulder muscles i.e. the onset and intensity of muscle activity is disturbed in the patient group during throwing. Hence, strength and stretching programs are recommended for athletes to reduce the risk of shoulder pain syndrome. The rehabilitation program can be focused on modifying the pattern of activity in upper trapezius, supraspinatus, latissimus dorsi and deltoid muscles in addition to pain control in the rehabilitation centers.

  8. Relationships Between Parents' Child-Rearing Attitudes and the Jumping and Throwing Performance of Their Preschool Children

    Science.gov (United States)

    Schnabl-Dickey, Elizabeth A.

    1977-01-01

    Permissive, indulgent home environments (characterized by low disciplinarian, high indulgent, and high protective child-rearing attitudes) were positively associated with superior throwing skill, while increased jumping skill was associated with higher maternal discipline. (MB)

  9. Rotational Acceleration during Head Impact Resulting from Different Judo Throwing Techniques

    OpenAIRE

    MURAYAMA, Haruo; HITOSUGI, Masahito; MOTOZAWA, Yasuki; OGINO, Masahiro; KOYAMA, Katsuhiro

    2014-01-01

    Most severe head injuries in judo are reported as acute subdural hematoma. It is thus necessary to examine the rotational acceleration of the head to clarify the mechanism of head injuries. We determined the rotational acceleration of the head when the subject is thrown by judo techniques. One Japanese male judo expert threw an anthropomorphic test device using two throwing techniques, Osoto-gari and Ouchigari. Rotational and translational head accelerations were measured with and without an ...

  10. Multiscale simulations of patchy particle systems combining Molecular Dynamics, Path Sampling and Green's Function Reaction Dynamics

    Science.gov (United States)

    Bolhuis, Peter

    Important reaction-diffusion processes, such as biochemical networks in living cells, or self-assembling soft matter, span many orders in length and time scales. In these systems, the reactants' spatial dynamics at mesoscopic length and time scales of microns and seconds is coupled to the reactions between the molecules at microscopic length and time scales of nanometers and milliseconds. This wide range of length and time scales makes these systems notoriously difficult to simulate. While mean-field rate equations cannot describe such processes, the mesoscopic Green's Function Reaction Dynamics (GFRD) method enables efficient simulation at the particle level provided the microscopic dynamics can be integrated out. Yet, many processes exhibit non-trivial microscopic dynamics that can qualitatively change the macroscopic behavior, calling for an atomistic, microscopic description. The recently developed multiscale Molecular Dynamics Green's Function Reaction Dynamics (MD-GFRD) approach combines GFRD for simulating the system at the mesocopic scale where particles are far apart, with microscopic Molecular (or Brownian) Dynamics, for simulating the system at the microscopic scale where reactants are in close proximity. The association and dissociation of particles are treated with rare event path sampling techniques. I will illustrate the efficiency of this method for patchy particle systems. Replacing the microscopic regime with a Markov State Model avoids the microscopic regime completely. The MSM is then pre-computed using advanced path-sampling techniques such as multistate transition interface sampling. I illustrate this approach on patchy particle systems that show multiple modes of binding. MD-GFRD is generic, and can be used to efficiently simulate reaction-diffusion systems at the particle level, including the orientational dynamics, opening up the possibility for large-scale simulations of e.g. protein signaling networks.

  11. Interplay between field observations and numerical modeling to understand temporal pulsing of tree root throw processes, Canadian Rockies, Canada

    Science.gov (United States)

    Martin, Y. E.; Johnson, E. A.; Chaikina, O.

    2013-10-01

    During the cycle of forest disturbance, regeneration, and maturity, tree mortality leading to topple is a regular occurrence. When tree topple occurs relatively soon after mortality and if the tree has attained some threshold diameter at breast height (dbh) at the time of death, then notable amounts of soil may be upheaved along with the root wad. This upheaval may result in sediment transfers and soil production. A combination of field evidence and numerical modeling is used herein to gain insights regarding the temporal dynamics of tree topple, associated root throw processes, and pit-mound microtopography. Results from our model of tree population dynamics demonstrate temporal patterns in root throw processes in subalpine forests of the Canadian Rockies, a region in which forests are affected largely by wildfire disturbance. As the forest regenerates after disturbance, the new cohort of trees has to reach a critical dbh before significant root plate upheaval can occur; in the subalpine forests of the Canadian Rockies, this may take up to ~ 102 years. Once trees begin to reach this critical dbh for root plate upheaval, a period of sporadic root throw arises that is caused by mortality of trees during competition. In due course, another wildfire will occur on the landscape and a period of much increased root throw activity then takes place for the next several decades; tree sizes and, therefore, the amount of sediment disturbance will be greater the longer the time period since the previous fire. Results of previous root throw studies covering a number of regional settings are used to guide an exercise in diffusion modeling with the aim of defining a range of reasonable diffusion coefficients for pit-mound degradation; the most appropriate values to fit the field data ranged from 0.01 m2 y- 1 to 0.1 m2 y- 1. A similar exercise is then undertaken that is guided by our field observations in subalpine forests of the Canadian Rockies. For these forests, the most

  12. Prediction of shot success for basketball free throws: visual search strategy.

    Science.gov (United States)

    Uchida, Yusuke; Mizuguchi, Nobuaki; Honda, Masaaki; Kanosue, Kazuyuki

    2014-01-01

    In ball games, players have to pay close attention to visual information in order to predict the movements of both the opponents and the ball. Previous studies have indicated that players primarily utilise cues concerning the ball and opponents' body motion. The information acquired must be effective for observing players to select the subsequent action. The present study evaluated the effects of changes in the video replay speed on the spatial visual search strategy and ability to predict free throw success. We compared eye movements made while observing a basketball free throw by novices and experienced basketball players. Correct response rates were close to chance (50%) at all video speeds for the novices. The correct response rate of experienced players was significantly above chance (and significantly above that of the novices) at the normal speed, but was not different from chance at both slow and fast speeds. Experienced players gazed more on the lower part of the player's body when viewing a normal speed video than the novices. The players likely detected critical visual information to predict shot success by properly moving their gaze according to the shooter's movements. This pattern did not change when the video speed was decreased, but changed when it was increased. These findings suggest that temporal information is important for predicting action outcomes and that such outcomes are sensitive to video speed.

  13. Strength, Endurance, Throwing Velocity and in-Water Jump Performance of Elite German Water Polo Players

    Directory of Open Access Journals (Sweden)

    Zinner Christoph

    2015-03-01

    Full Text Available The purpose of this study was threefold: 1 to assess the eggbeater kick and throwing performance using a number of water polo specific tests, 2 to explore the relation between the eggbeater kick and throwing performance, and 3 to investigate the relation between the eggbeater kick in the water and strength tests performed in a controlled laboratory setting in elite water polo players. Fifteen male water polo players of the German National Team completed dynamic and isometric strength tests for muscle groups (adductor, abductor, abdominal, pectoralis frequently used during water polo. After these laboratory strength tests, six water polo specific in-water tests were conducted. The eggbeater kick assessed leg endurance and agility, maximal throwing velocity and jump height. A 400 m test and a sprint test examined aerobic and anaerobic performance. The strongest correlation was found between jump height and arm length (p < 0.001, r = 0.89. The laboratory diagnostics of important muscles showed positive correlations with the results of the in-water tests (p < 0.05, r = 0.52-0.70. Muscular strength of the adductor, abdominal and pectoralis muscles was positively related to in-water endurance agility as assessed by the eggbeater kick (p < 0.05; r = 0.53-0.66. Findings from the current study emphasize the need to assess indices of water polo performance both in and out of the water as well as the relation among these parameters to best assess the complex profile of water polo players.

  14. Paths correlation matrix.

    Science.gov (United States)

    Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang

    2015-09-15

    Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.

  15. Spreading paths in partially observed social networks

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A.

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  16. Spreading paths in partially observed social networks.

    Science.gov (United States)

    Onnela, Jukka-Pekka; Christakis, Nicholas A

    2012-03-01

    Understanding how and how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading paths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using static, structurally realistic social networks as platforms for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Although partial observation inflates the length of the shortest path, the stochastic nature of the spreading process also frequently derails the dynamic path from the shortest path. We find that the partially observed shortest path does not necessarily give an inflated estimate of the length of the process path; in fact, partial observation may, counterintuitively, make the path seem shorter than it actually is.

  17. A Path Space Extension for Robust Light Transport Simulation

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Pantaleoni, Jacopo; Jensen, Henrik Wann

    2012-01-01

    We present a new sampling space for light transport paths that makes it possible to describe Monte Carlo path integration and photon density estimation in the same framework. A key contribution of our paper is the introduction of vertex perturbations, which extends the space of paths with loosely...

  18. Strength Training Using Elastic Bands: Improvement of Muscle Power and Throwing Performance in Young Female Handball Players.

    Science.gov (United States)

    Mascarin, Naryana Cristina; de Lira, Claudio Andre Barbosa; Vancini, Rodrigo Luiz; de Castro Pochini, Alberto; da Silva, Antonio Carlos; Dos Santos Andrade, Marilia

    2017-05-01

    Imbalance in shoulder-rotator muscles has been considered a risk factor for injuries in handball. Strength training programs (STPs) may play an important preventive role. To verify the effects of an STP using elastic bands on shoulder muscles and ball-throwing speed. Randomized and prospective controlled trial. Exercise physiology laboratory. Thirty-nine female handball players were randomly assigned to an experimental (EG, n = 21, 15.3 ± 1.1 y) or a control (CG, n = 18, 15.0 ± 0.8 y) group. The EG performed the STP with elastic-band progressive exercises for 6 wk before regular handball training, and the CG underwent only their regular training. Before and after the STP, both groups underwent a ball-throwing-speed test and isokinetic test to assess shoulder internal- (IR) and external-rotator muscle performance. Average power values for IR muscles presented a significant group-vs-time interaction effect (F = 3.9, P = .05); EG presented significantly higher values after the STP (P = .03). Ball speed presented higher values in EG after the STP in standing (P = .04) and jumping (P = .03) throws. IR peak-torque values and balance in shoulder-rotator muscles presented no group-vs-time interaction effect. STP using elastic bands performed for 6 wk was effective to improve muscle power and ball speed for young female handball players.

  19. Biomecánica de la técnica de lanzamiento de disco. Influencia de la trayectoria del disco en la velocidad de liberación. Biomechanics of discus throw technique. The influence of the discus path on the velocity of release.

    Directory of Open Access Journals (Sweden)

    Floría Martín, Pablo

    2006-10-01

    Full Text Available ResumenEl objetivo del estudio fue analizar la influencia de la trayectoria del disco, durante las dos últimas fases del lanzamiento, en su velocidad de liberación. Se analizaron 25 lanzamientos pertenecientes a 8 hombres y 5 mujeres, seleccionados por la Real Federación Española de Atletismo, que participaron en 5 competiciones. Se realizó un análisis cinemático tridimensional utilizando cámaras de cine de alta velocidad (100Hz. Las imágenes y los datos se trataron utilizando Fotogram-IBV y las variables biomecánicas de eficacia de latécnica se obtuvieron mediante la rutina de cálculo Biodisc.Para estudiar las asociaciones entre variables se aplicó el coeficiente de correlación de Pearson. Las variables altura máxima del disco (DISCOmax e incremento de la alturaentre la mínima y la de liberación (∆h_DISCOmin-DISCOlib guardan correlación significativa con la velocidad vertical del disco en el momento de la liberación (VvDISCOlib mientras que la altura mínima del disco (hDISCOmin fue significativa para mujeres y la altura en el instante de liberación(hDISCOlib lo fue para hombres, sugiriendo diferente estrategia para la consecución de la altura del disco necesaria para el vuelo. El ángulo del hombro derecho (Θ_HOMBd se halló relacionado con hDISCO max, hDISCO min y hDISCO lib mientras que el ángulo de la rodilla derecha(Θ_RODd se relacionó con un descenso del disco, necesario en mujeres, para aumentar el recorrido de aceleración. Por otro lado, ciertos aspectos técnicos utilizados por los entrenadores para la enseñanza y corrección de la técnica de sus atletas tienen una evidencia científica, por lo que se aconseja sean observados sistemáticamente.AbstractThe objective of this study was to analyze the influence of discus path on its release velocity during the last two phases of throwing event. It were analyzed 25 throwing belong to 8 men and 5 women selected for Royal Spanish Athletics Federation, in 5

  20. Don't throw the bathwater in with the baby.

    Science.gov (United States)

    Lichtenstein, Paul

    2012-01-01

    The Presidential Address of the European Association of Developmental Psychology this year concerned how genes and environments interplay to shape loneliness and other developmental psychological relevant outcomes. This is a very welcome. However, when developmental psychology now is ready to integrate recent genetic and neuroscience knowledge and methods, I think it would be very wise to not uncritical go through the mistakes that have be done in other disciplines and instead learn from their hard lessons. I discuss some problems (genes versus environments, identifying gene for a phenotype, environments cause of developmental outcomes, and gene X environment interaction and epigenetics) and some suggestions for solutions which can be used to avoid throwing in the bathwater with the baby.

  1. Rotational acceleration during head impact resulting from different judo throwing techniques.

    Science.gov (United States)

    Murayama, Haruo; Hitosugi, Masahito; Motozawa, Yasuki; Ogino, Masahiro; Koyama, Katsuhiro

    2014-01-01

    Most severe head injuries in judo are reported as acute subdural hematoma. It is thus necessary to examine the rotational acceleration of the head to clarify the mechanism of head injuries. We determined the rotational acceleration of the head when the subject is thrown by judo techniques. One Japanese male judo expert threw an anthropomorphic test device using two throwing techniques, Osoto-gari and Ouchi-gari. Rotational and translational head accelerations were measured with and without an under-mat. For Osoto-gari, peak resultant rotational acceleration ranged from 4,284.2 rad/s(2) to 5,525.9 rad/s(2) and peak resultant translational acceleration ranged from 64.3 g to 87.2 g; for Ouchi-gari, the accelerations respectively ranged from 1,708.0 rad/s(2) to 2,104.1 rad/s(2) and from 120.2 g to 149.4 g. The resultant rotational acceleration did not decrease with installation of an under-mat for both Ouchi-gari and Osoto-gari. We found that head contact with the tatami could result in the peak values of translational and rotational accelerations, respectively. In general, because kinematics of the body strongly affects translational and rotational accelerations of the head, both accelerations should be measured to analyze the underlying mechanism of head injury. As a primary preventative measure, throwing techniques should be restricted to participants demonstrating ability in ukemi techniques to avoid head contact with the tatami.

  2. The BD Onclarity HPV assay on SurePath collected samples meets the International Guidelines for Human Papillomavirus Test Requirements for Cervical Screening

    DEFF Research Database (Denmark)

    Ejegod, Ditte; Bottari, Fabio; Pedersen, Helle

    2016-01-01

    This study describes a validation of the BD Onclarity HPV (Onclarity) assay using the international guidelines for HPV test requirements for cervical cancer screening of women 30 years and above using Danish SurePath screening samples. The clinical specificity (0.90, 95% CI: 0.88-0.91) and sensit......This study describes a validation of the BD Onclarity HPV (Onclarity) assay using the international guidelines for HPV test requirements for cervical cancer screening of women 30 years and above using Danish SurePath screening samples. The clinical specificity (0.90, 95% CI: 0.......88-0.91) and sensitivity (0.97, 95% CI: 0.87-1.0) of the Onclarity assay were shown to be non-inferior to the reference assay (specificity 0.90, 95% CI: 0.88-0.92, sensitivity 0.98, 95% CI: 0.91-1.0). The intra-laboratory reproducibility of Onclarity was 97% with a lower confidence bound of 96% (kappa value: 0...

  3. Treatment of stress fracture of the olecranon in throwing athletes with internal fixation through a small incision

    Directory of Open Access Journals (Sweden)

    Fujioka Hiroyuki

    2012-12-01

    Full Text Available Abstract The present study is a report of retrospective case series of stress fracture of the olecranon. Six patients presented posterior elbow pain in throwing in baseball and softball, but fracture was not diagnosed in radiographs. We detected stress fracture of the olecranon using computed tomographic (CT scan and treated the patient with internal fixation with a headless cannulated double threaded screw through a small skin incision. All patients returned to competitive level without elbow complaints after the operation. When throwing athletes present with unusual posterior elbow pain and no significant findings on radiographs, a CT scan examination should be performed. We recommend surgical treatment of internal fixation with a screw through a small skin incision, as a good option for stress fracture of the olecranon in order to allow early return to sports activity in competitive athletes.

  4. Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

    Science.gov (United States)

    Wutich, A.; White, A. C.; White, D. D.; Larson, K. L.; Brewis, A.; Roberts, C.

    2014-01-01

    In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

  5. Path coupling and aggregate path coupling

    CERN Document Server

    Kovchegov, Yevgeniy

    2018-01-01

    This book describes and characterizes an extension to the classical path coupling method applied to statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, the aggregate path coupling method is used to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The book shows how the parameter regions for rapid mixing for several classes of statistical mechanical models are derived using the aggregate path coupling method.

  6. UPAYA MENINGKATKAN MINAT BELAJAR SISWA MELALUI MODEL PEMBELAJARAN KOOPERATIF TIPE SNOWBALL THROWING PADA MATA DIKLAT KOMUNIKASI SISWA SMK

    Directory of Open Access Journals (Sweden)

    Dian Pratiwi

    2016-02-01

    Full Text Available Tujuan penelitian untuk meningkatkan minat belajar siswa melalui model pembelajaran kooperatif tipe Snowball Throwing pada mata diklat komunikasi siswa kelas X AP SMK Gatra Praja Pekalongan. Subjek penelitian ini adalah siswa kelas X AP yang berjumlah 37 siswa. jenis penelitian adalah penelitian tindakan kelas, dilakukan dalam dua siklus. Teknik pengumpulan data menggunakan observasi, kuesioner,dan dokumentasi. Hasil penelitian menunjukkan minat belajar hasil dari lembar pengamatan siklus I sebesar 60,33% dengan kategori kurang berminat dan pada siklus II menjadi 75,27% dengan kategori berminat. Sedangkan hasil minat belajar dari angket/kuesioner pada siklus I 68,90% dengan kategori berminat dan pada siklus II menjadi 76,71% dengan kategori berminat. Kesimpulanya Penerapan pembelajaran menggunakan model Snowball Throwing dapat meningkatkan minat belajar siswa kelas X AP pada mata diklat komunikasi SMK Gatra Praja Pekalongan, terbukti setiap siklusnya mengalami peningkatan. This study is aimed at improving students’ interest through cooperative learning model Snowball Throwing at Communication Training Subject in Class X Office Administration of Gatra Praja Vocational High School Pekalongan. Subject of this research was the 37 students of XI AP. This type of research is classroom action research and conducted in two cycles. Data collecting technique used is observation, questionnaires, and documentation. The result of the research shows that the learning interest form of the observation sheet on the first cycle is 60.33% with less interest category and the second cycle, it turns into 75.27% to the category of interest. While the results of the learning interest from the questionnaire in the first cycle is 68.90% of the maximum percentage of the interest category and the second cycle it turns into 76.71% to the category of interest. The conclusion is the application of learning using models Snowball Throwing can increase students’ interest in

  7. Don’t throw the bathwater in with the baby

    Science.gov (United States)

    Lichtenstein, Paul

    2013-01-01

    The Presidential Address of the European Association of Developmental Psychology this year concerned how genes and environments interplay to shape loneliness and other developmental psychological relevant outcomes. This is a very welcome. However, when developmental psychology now is ready to integrate recent genetic and neuroscience knowledge and methods, I think it would be very wise to not uncritical go through the mistakes that have be done in other disciplines and instead learn from their hard lessons. I discuss some problems (genes versus environments, identifying gene for a phenotype, environments cause of developmental outcomes, and gene X environment interaction and epigenetics) and some suggestions for solutions which can be used to avoid throwing in the bathwater with the baby. PMID:23745130

  8. Path Creation, Path Dependence and Breaking Away from the Path

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  9. Optimal Paths in Gliding Flight

    Science.gov (United States)

    Wolek, Artur

    Underwater gliders are robust and long endurance ocean sampling platforms that are increasingly being deployed in coastal regions. This new environment is characterized by shallow waters and significant currents that can challenge the mobility of these efficient (but traditionally slow moving) vehicles. This dissertation aims to improve the performance of shallow water underwater gliders through path planning. The path planning problem is formulated for a dynamic particle (or "kinematic car") model. The objective is to identify the path which satisfies specified boundary conditions and minimizes a particular cost. Several cost functions are considered. The problem is addressed using optimal control theory. The length scales of interest for path planning are within a few turn radii. First, an approach is developed for planning minimum-time paths, for a fixed speed glider, that are sub-optimal but are guaranteed to be feasible in the presence of unknown time-varying currents. Next the minimum-time problem for a glider with speed controls, that may vary between the stall speed and the maximum speed, is solved. Last, optimal paths that minimize change in depth (equivalently, maximize range) are investigated. Recognizing that path planning alone cannot overcome all of the challenges associated with significant currents and shallow waters, the design of a novel underwater glider with improved capabilities is explored. A glider with a pneumatic buoyancy engine (allowing large, rapid buoyancy changes) and a cylindrical moving mass mechanism (generating large pitch and roll moments) is designed, manufactured, and tested to demonstrate potential improvements in speed and maneuverability.

  10. Modelling the Small Throw Fault Effect on the Stability of a Mining Roadway and Its Verification by In Situ Investigation

    Directory of Open Access Journals (Sweden)

    Małkowski Piotr

    2017-12-01

    Full Text Available The small throw fault zones cause serious problems for mining engineers. The knowledge about the range of fractured zone around the roadway and about roadway’s contour deformations helps a lot with the right support design or its reinforcement. The paper presents the results of numerical analysis of the effect of a small throw fault zone on the convergence of the mining roadway and the extent of the fracturing induced around the roadway. The computations were performed on a dozen physical models featuring various parameters of rock mass and support for the purpose to select the settings that reflects most suitably the behavior of tectonically disturbed and undisturbed rocks around the roadway. Finally, the results of the calculations were verified by comparing them with in situ convergence measurements carried out in the maingate D-2 in the “Borynia-Zofiówka-Jastrzębie” coal mine. Based on the results of measurements it may be concluded that the rock mass displacements around a roadway section within a fault zone during a year were four times in average greater than in the section tectonically unaffected. The results of numerical calculations show that extent of the yielding zone in the roof reaches two times the throw of the fault, in the floor 3 times the throw, and horizontally approx. 1.5 to 1.8 times the width of modelled fault zone. Only a few elasto-plastic models or models with joints between the rock beds can be recommended for predicting the performance of a roadway which is within a fault zone. It is possible, using these models, to design the roadway support of sufficient load bearing capacity at the tectonically disturbed section.

  11. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-01-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pvolleyball players. Future studies should evaluate differential program effects in less experienced and younger players. Key points Plyometric- and skill-based-conditioning resulted in improvements in jumping and throwing capacities, but plyometric training additionally induced positive changes in anthropometrics and sprint-capacity The changes induced by plyometric training were larger in magnitude than those achieved by skill-based conditioning. The higher intensity together with possibility of more accurate adjustment of training load in plyometric training are probably the most important determinant of such differential influence. It is likely that the skill-based conditioning program did not result in changes of higher magnitude because of the players’ familiarity with volleyball-related skills. PMID:29238253

  12. Path-integral computation of superfluid densities

    International Nuclear Information System (INIS)

    Pollock, E.L.; Ceperley, D.M.

    1987-01-01

    The normal and superfluid densities are defined by the response of a liquid to sample boundary motion. The free-energy change due to uniform boundary motion can be calculated by path-integral methods from the distribution of the winding number of the paths around a periodic cell. This provides a conceptually and computationally simple way of calculating the superfluid density for any Bose system. The linear-response formulation relates the superfluid density to the momentum-density correlation function, which has a short-ranged part related to the normal density and, in the case of a superfluid, a long-ranged part whose strength is proportional to the superfluid density. These facts are discussed in the context of path-integral computations and demonstrated for liquid 4 He along the saturated vapor-pressure curve. Below the experimental superfluid transition temperature the computed superfluid fractions agree with the experimental values to within the statistical uncertainties of a few percent in the computations. The computed transition is broadened by finite-sample-size effects

  13. Understanding and acknowledging the ice throw hazard - consequences for regulatory frameworks, risk perception and risk communication

    Science.gov (United States)

    Bredesen, R. E.; Drapalik, M.; Butt, B.

    2017-11-01

    This study attempts to provide the necessary framework required to make sufficiently informed decisions regarding the safety implications of ice throw. The framework elaborates on how to cope with uncertainties, and how to describe results in a meaningful and useful manner to decision makers. Moreover, it points out the moral, judicial and economical obligations of wind turbine owners such that they are able to minimize risk of ice throws as much as possible. Building on the strength of knowledge as well as accounting for uncertainty are also essential in enabling clear communication with stakeholders on the most important/critical/vital issues. With increasing empirical evidence, one can assign a higher confidence level on the expert opinions on safety. Findings regarding key uncertainties of ice risk assessments are presented here to support the ongoing IEA Wind Task 19's work on creating the international guidelines on ice risk assessment due in 2018 (Krenn et al. 2017)[1-6]. In addition the study also incorporates the findings of a Norwegian information project, which focuses on the ice throw hazard for the public (Bredesen, Flage, Butt, Winterwind 2018)[7-9]. This includes measures to reduce damage and hazard from wind turbines for the general public. Recent theory of risk assessment questions the use of risk criteria for achieving optimum risk reduction and favours the use of the ALARA (as low as reasonably achievable) principle. Given the several practical problems associated with the ALARA approach (e.g. judicial realization), a joint approach, which uses a minimum set of criteria as well as the obligation to meet ALARA is suggested (associated with acceptable cost). The actual decision about acceptance criteria or obligations is a societal one, thus suggestions can be made at best. Risk acceptance, risk perception and risk communication are inextricably linked and should thus never be considered separately. Risk communication can shape risk perception

  14. The overarm-throwing pattern among U-14 ASA female softball players: a comparative study of gender, culture, and experience.

    Science.gov (United States)

    Petranek, Laura Jones; Barton, Gina V

    2011-06-01

    A developmental description of overarm-throwing characteristics of U-14female ASA softballplayers is presented here. Comparisons were made between these athletes and teens of similar age in the United States (Runion, Roberton, & Langendorfe 2003) and in Germany (Ehl, Roberton, & Langendorfer, 2005). A majority of the softball players demonstrated the most advanced developmental levels for the backswing foot, humerus, and forearm components. Seventy percent (n = 26) demonstrated a Level 2 trunk, while 30% (n = 11) demonstrated a differentiated trunk, Level 3. The average throwing velocity was 62.58 ft/s (19.07 m/s). Comparisons were made to girls with less throwing experience in the United States (Runion et al.) and Germany (Ehl et al.); the softball players threw with greater velocity (9.12ft/s [2.77 m/s]and 15.89 ft/s [4.84 m/s], respectively) and demonstrated superior trunk, humerus, and forearm actions. The boys from both countries threw the ball faster than the softball players. Significant chi-square analyses found the softball players had superior humeral actions (Level 3) compared to the German boys and superior forearm actions (Level 3) compared to both groups of bays. Experience seems to have an impact when comparisons among girls are made; yet, explanations for differences seen between boys and girls still remain unclear and warrant further research.

  15. Ability Beliefs, Task Value, and Performance as a Function of Race in a Dart-Throwing Task

    Science.gov (United States)

    Gao, Zan; Kosma, Maria; Harrison, Louis, Jr.

    2009-01-01

    This study examines differences in self-efficacy, expectancy-related beliefs, task value, and performance in a dart-throwing task as a function of race among diverse college students using the expectancy-value model and self-efficacy theory. It also examines the predictive contributions of these beliefs on task performance within each racial…

  16. Energy consumption of ProTaper Next X1 after glide path with PathFiles and ProGlider.

    Science.gov (United States)

    Berutti, Elio; Alovisi, Mario; Pastorelli, Michele Angelo; Chiandussi, Giorgio; Scotti, Nicola; Pasqualini, Damiano

    2014-12-01

    Instrument failure caused by excessive torsional stress can be controlled by creating a manual or mechanical glide path. The ProGlider single-file system (Dentsply Maillefer, Ballaigues, Switzerland) was recently introduced to perform a mechanical glide path. This study was designed to compare the effect of a glide path performed with PathFiles (Dentsply Maillefer) and ProGlider on torque, time, and pecking motion required for ProTaper Next X1 (Dentsply Maillefer) to reach the full working length in simulated root canals. Forty Endo Training Blocks (Dentsply Maillefer) were used. Twenty were prepared with a mechanical glide path using PathFiles 1 and 2 (the PathFile group), and 20 were prepared with a mechanical glide path using a ProGlider single file (the ProGlider group). All samples were shaped with ProTaper Next X1 driven by an endodontic motor connected to a digital wattmeter. The required torque for root canal instrumentation was analyzed by evaluating the electrical power consumption of the endodontic engine. Electric power consumption (mW/h), elapsed time (seconds), and number of pecking motions required to reach the full working length with ProTaper Next X1 were calculated. Differences among groups were analyzed with the parametric Student t test for independent data (P < .05). Elapsed time and electric power consumption were significantly different between groups (P = .0001 for both). ProGlider appears to perform more efficiently than PathFiles in decreasing electric power consumption of ProTaper Next X1 to reach the full working length. This study confirmed the ability of ProGlider to reduce stress in ProTaper Next X1 during shaping through a glide path and preliminary middle and coronal preflaring. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Deliberate utilization of interaction torques brakes elbow extension in a fast throwing motion.

    Science.gov (United States)

    Hore, Jon; Debicki, Derek B; Gribble, Paul L; Watts, Sherry

    2011-05-01

    We tested the hypothesis that in fast arm movements the CNS deliberately utilizes interaction torques to decelerate (brake) joint rotations. Twelve subjects performed fast 2-D overarm throws in which large elbow extension velocities occurred. Joint motions were computed from recordings made with search coils; joint torques were calculated using inverse dynamics. After ball release, a large follow-through shoulder extension acceleration occurred that was initiated by shoulder extensor muscle torque. This shoulder acceleration produced a flexor interaction torque at the elbow that initiated elbow deceleration (braking). An instantaneous mechanical interaction of passive torques then occurred between elbow and shoulder, i.e., elbow extension deceleration produced a large shoulder extensor interaction torque that contributed to the shoulder extension acceleration which, simultaneously, produced a large elbow flexor interaction torque that contributed to elbow extension deceleration, and so on. Late elbow flexor muscle torque also contributed to elbow deceleration. The interaction of passive torques between shoulder and elbow was braked by shoulder flexor muscle torque. In this mechanism, shoulder musculature contributed to braking elbow extension in two ways: shoulder extensors initiated the mechanical interaction of passive torques between shoulder and elbow and shoulder flexors dissipated kinetic energy from elbow braking. It is concluded that, in fast 2-D throws, the CNS deliberately utilizes powerful interaction torques between shoulder and elbow to brake motion at the elbow.

  18. Core self-evaluations and work engagement: Testing a perception, action, and development path.

    Directory of Open Access Journals (Sweden)

    Maria Tims

    Full Text Available Core self-evaluations (CSE have predictive value for important work outcomes such as job satisfaction and job performance. However, little is known about the mechanisms that may explain these relationships. The purpose of the present study is to contribute to CSE theory by proposing and subsequently providing a first test of theoretically relevant mediating paths through which CSE may be related to work engagement. Based on approach/avoidance motivation and Job Demands-Resources theory, we examined a perception (via job characteristics, action (via job crafting, and development path (via career competencies. Two independent samples were obtained from employees working in Germany and The Netherlands (N = 303 and N = 404, respectively. When taking all mediators into account, results showed that the perception path represented by autonomy and social support played a minor role in the relationship between CSE and work engagement. Specifically, autonomy did not function as a mediator in both samples while social support played a marginally significant role in the CSE-work engagement relationship in sample 1 and received full support in sample 2. The action path exemplified by job crafting mediated the relationship between CSE and work engagement in both samples. Finally, the development path operationalized with career competencies mediated the relationship between CSE and work engagement in sample 1. The study presents evidence for an action and development path over and above the often tested perception path to explain how CSE is related to work engagement. This is one of the first studies to propose and show that CSE not only influences perceptions but also triggers employee actions and developmental strategies that relate to work engagement.

  19. Core self-evaluations and work engagement: Testing a perception, action, and development path

    Science.gov (United States)

    Akkermans, Jos

    2017-01-01

    Core self-evaluations (CSE) have predictive value for important work outcomes such as job satisfaction and job performance. However, little is known about the mechanisms that may explain these relationships. The purpose of the present study is to contribute to CSE theory by proposing and subsequently providing a first test of theoretically relevant mediating paths through which CSE may be related to work engagement. Based on approach/avoidance motivation and Job Demands-Resources theory, we examined a perception (via job characteristics), action (via job crafting), and development path (via career competencies). Two independent samples were obtained from employees working in Germany and The Netherlands (N = 303 and N = 404, respectively). When taking all mediators into account, results showed that the perception path represented by autonomy and social support played a minor role in the relationship between CSE and work engagement. Specifically, autonomy did not function as a mediator in both samples while social support played a marginally significant role in the CSE–work engagement relationship in sample 1 and received full support in sample 2. The action path exemplified by job crafting mediated the relationship between CSE and work engagement in both samples. Finally, the development path operationalized with career competencies mediated the relationship between CSE and work engagement in sample 1. The study presents evidence for an action and development path over and above the often tested perception path to explain how CSE is related to work engagement. This is one of the first studies to propose and show that CSE not only influences perceptions but also triggers employee actions and developmental strategies that relate to work engagement. PMID:28787464

  20. Core self-evaluations and work engagement: Testing a perception, action, and development path.

    Science.gov (United States)

    Tims, Maria; Akkermans, Jos

    2017-01-01

    Core self-evaluations (CSE) have predictive value for important work outcomes such as job satisfaction and job performance. However, little is known about the mechanisms that may explain these relationships. The purpose of the present study is to contribute to CSE theory by proposing and subsequently providing a first test of theoretically relevant mediating paths through which CSE may be related to work engagement. Based on approach/avoidance motivation and Job Demands-Resources theory, we examined a perception (via job characteristics), action (via job crafting), and development path (via career competencies). Two independent samples were obtained from employees working in Germany and The Netherlands (N = 303 and N = 404, respectively). When taking all mediators into account, results showed that the perception path represented by autonomy and social support played a minor role in the relationship between CSE and work engagement. Specifically, autonomy did not function as a mediator in both samples while social support played a marginally significant role in the CSE-work engagement relationship in sample 1 and received full support in sample 2. The action path exemplified by job crafting mediated the relationship between CSE and work engagement in both samples. Finally, the development path operationalized with career competencies mediated the relationship between CSE and work engagement in sample 1. The study presents evidence for an action and development path over and above the often tested perception path to explain how CSE is related to work engagement. This is one of the first studies to propose and show that CSE not only influences perceptions but also triggers employee actions and developmental strategies that relate to work engagement.

  1. Effects of Fatigue on Throwing Performance in Experienced Team Handball Players

    Science.gov (United States)

    Nuño, Alberto; van den Tillaar, Roland; Guisado, Rafael; Martín, Ignacio; Martinez, Isidoro; Chirosa, Luis J.

    2016-01-01

    Abstract The purpose of this study was to investigate the effect of central and peripheral physiological fatigue on throwing accuracy and ball release velocity in team handball. Twenty male subjects (age 24.7 ± 3.9 yrs, body mass 88.5 ± 5.0 kg, body height 1.86 ± 0.05 m, training experience 12.7 ± 3.8 yrs) from one handball team participated in this study. The participants completed four sets of eight laps of a circuit that consisted of specific team handball drills/exercises, with decreasing recovery times between the laps in each set in order to induce physiological fatigue. Duration of the recovery intervals determined the description of the effort made in each set: “light" (80 s recovery between laps), “moderate" (40 s), “hard" (20 s) and “very hard" (10 s). A heart rate, concentration of lactate in blood and the rate of perceived exertion (RPE) were recorded. Ball velocity and accuracy were measured after each set and they both decreased during a fatigue protocol. However, accuracy only decreased significantly in the end of the protocol, while ball release was already affected after the first round of the protocol. The results substantiate the initial hypothesis and confirm that both throwing accuracy and ball release velocity decrease significantly as physiological fatigue increases. These variables began to decrease when the fatigue quantification values were high or very high. The findings can be used by coaches to develop training programs to teach players how to identify fatigue thresholds and combat the effects of fatigue through decision-making skills at critical game moments. PMID:28031762

  2. NiThrowTM a dedicated tool to D and D applications

    International Nuclear Information System (INIS)

    Objois, Laurent; Moggia, Fabrice; Damerval, Frederique; Varet, Thierry; Toulemonde, Valerie; Richard, Frederic

    2012-09-01

    D and D operations of nuclear site facilities, is a long, complicated and important stage. Usually, such operations involve the implementation of a large number of different technologies (mechanicals and/or chemicals) dedicated to cutting and decontamination operations. Such processes proved to work since facilities are being decommissioned. However as larger projects are foreseen, the capability of such applications to fulfil the requirement in term of economics, techniques and environment/social remains uncertain. Indeed, several aspects such as the efficiency, the speed but also the number of operators required to operate and for sure the quantity of generated wastes remain an important key point. In that context, it appears important to develop a new technology capable to be quicker, safer, and friendlier for operators and the environment. In this context, the Clean-Up Business Unit of AREVA group (BE/CL) with its partner Air Liquide worked on the development of a new cryogenic process. Started in 2008, this work was based on the use of highly pressurized liquid nitrogen in order to achieve the three mains D and D operations which are: - Cutting. - Surface decontamination. - Concrete scabbling. In this paper, three parts will be presented. The first one will give a brief overview of this new technology so called NiThrow TM . The second one will exhibit the results obtained during our different tests. And finally, the third part will be focused on the R and D developments we realized in order to fully nuclearized this NiThrow TM technology but also on its tuning in order to qualify it for nuclear environments. (authors)

  3. Designing Pay-As-You-Throw schemes in municipal waste management services: A holistic approach

    International Nuclear Information System (INIS)

    Elia, Valerio; Gnoni, Maria Grazia; Tornese, Fabiana

    2015-01-01

    Highlights: • Pay-As-You-Throw (PAYT) schemes are becoming widespread in several countries. • Economic, organizational and technological issues have to be integrated in an efficient PAYT model design. • Efficiency refers to a PAYT system which support high citizen participation rates as well as economic sustainability. • Different steps and constraints have to be evaluated from collection services to type technologies. • An holistic approach is discussed to support PAYT systems diffusion. - Abstract: Pay-As-You-Throw (PAYT) strategies are becoming widely applied in solid waste management systems; the main purpose is to support a more sustainable – from economic, environmental and social points of view – management of waste flows. Adopting PAYT charging models increases the complexity level of the waste management service as new organizational issues have to be evaluated compared to flat charging models. In addition, innovative technological solutions could also be adopted to increase the overall efficiency of the service. Unit pricing, user identification and waste measurement represent the three most important processes to be defined in a PAYT system. The paper proposes a holistic framework to support an effective design and management process. The framework defines most critical processes and effective organizational and technological solutions for supporting waste managers as well as researchers

  4. Designing Pay-As-You-Throw schemes in municipal waste management services: A holistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Elia, Valerio; Gnoni, Maria Grazia, E-mail: mariagrazia.gnoni@unisalento.it; Tornese, Fabiana

    2015-10-15

    Highlights: • Pay-As-You-Throw (PAYT) schemes are becoming widespread in several countries. • Economic, organizational and technological issues have to be integrated in an efficient PAYT model design. • Efficiency refers to a PAYT system which support high citizen participation rates as well as economic sustainability. • Different steps and constraints have to be evaluated from collection services to type technologies. • An holistic approach is discussed to support PAYT systems diffusion. - Abstract: Pay-As-You-Throw (PAYT) strategies are becoming widely applied in solid waste management systems; the main purpose is to support a more sustainable – from economic, environmental and social points of view – management of waste flows. Adopting PAYT charging models increases the complexity level of the waste management service as new organizational issues have to be evaluated compared to flat charging models. In addition, innovative technological solutions could also be adopted to increase the overall efficiency of the service. Unit pricing, user identification and waste measurement represent the three most important processes to be defined in a PAYT system. The paper proposes a holistic framework to support an effective design and management process. The framework defines most critical processes and effective organizational and technological solutions for supporting waste managers as well as researchers.

  5. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  6. APTIMA assay on SurePath liquid-based cervical samples compared to endocervical swab samples facilitated by a real time database

    Directory of Open Access Journals (Sweden)

    Khader Samer

    2010-01-01

    Full Text Available Background: Liquid-based cytology (LBC cervical samples are increasingly being used to test for pathogens, including: HPV, Chlamydia trachomatis (CT and Neisseria gonorrhoeae (GC using nucleic acid amplification tests. Several reports have shown the accuracy of such testing on ThinPrep (TP LBC samples. Fewer studies have evaluated SurePath (SP LBC samples, which utilize a different specimen preservative. This study was undertaken to assess the performance of the Aptima Combo 2 Assay (AC2 for CT and GC on SP versus endocervical swab samples in our laboratory. Materials and Methods: The live pathology database of Montefiore Medical Center was searched for patients with AC2 endocervical swab specimens and SP Paps taken the same day. SP samples from CT- and/or GC-positive endocervical swab patients and randomly selected negative patients were studied. In each case, 1.5 ml of the residual SP vial sample, which was in SP preservative and stored at room temperature, was transferred within seven days of collection to APTIMA specimen transfer tubes without any sample or patient identifiers. Blind testing with the AC2 assay was performed on the Tigris DTS System (Gen-probe, San Diego, CA. Finalized SP results were compared with the previously reported endocervical swab results for the entire group and separately for patients 25 years and younger and patients over 25 years. Results: SP specimens from 300 patients were tested. This included 181 swab CT-positive, 12 swab GC-positive, 7 CT and GC positive and 100 randomly selected swab CT and GC negative patients. Using the endocervical swab results as the patient′s infection status, AC2 assay of the SP samples showed: CT sensitivity 89.3%, CT specificity 100.0%; GC sensitivity and specificity 100.0%. CT sensitivity for patients 25 years or younger was 93.1%, versus 80.7% for patients over 25 years, a statistically significant difference (P = 0.02. Conclusions: Our results show that AC2 assay of 1.5 ml SP

  7. The Relationships between Ball Throwing Velocity and Physical-Psychomotor Features for Talent Identification in Physical Education

    Science.gov (United States)

    Karadenizli, Zeynep Inci

    2016-01-01

    The aim of this study is to investigate the relationships between ball throwing velocity (BTV), and physical features and anaerobic power (AP) for talent identification in team handball players. Players (n: 54) at 21,91 ± 4,94 age, training experience 11,19 ± 4,46 years participated voluntarily to study. These players consist of 54 Turkish…

  8. Hybrid Capture 2 and cobas human papillomavirus assays perform similarly on SurePath samples from women with abnormalities

    DEFF Research Database (Denmark)

    Fornari, D; Rebolj, M; Bjerregaard, B

    2016-01-01

    OBJECTIVE: In two laboratories (Departments of Pathology, Copenhagen University Hospitals of Herlev and Hvidovre), we compared cobas and Hybrid Capture 2 (HC2) human papillomavirus (HPV) assays using SurePath® samples from women with atypical squamous cells of undetermined significance (ASCUS......) at ≥30 years and women after treatment of cervical intraepithelial neoplasia (CIN). METHODS: Samples from 566 women with ASCUS and 411 women after treatment were routinely tested with HC2 and, thereafter, with cobas. Histological outcomes were retrieved from the Danish Pathology Data Base. We calculated...... the overall agreement between the assays, and compared their sensitivity and specificity for ≥CIN2. RESULTS: In women with ASCUS, HC2 and cobas testing results were similar in the two laboratories. The overall agreement was 91% (95% CI, 88-93). After CIN treatment, the overall agreement was 87% (95% CI, 82...

  9. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning.

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-12-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pPlyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes), and improved their performance in S20M (moderate ES; 8%), MBT (very large ES; 25%), CMJ (large ES; 27%), and SBJ (moderate ES; 8%). Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%), SBJ (small ES; 3%), and MBT (large ES; 9%). The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  10. Can we throw information out of visual working memory and does this leave informational residue in long-term memory?

    Directory of Open Access Journals (Sweden)

    Ashleigh Monette Maxcey

    2014-04-01

    Full Text Available Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this proposal. However, given the infinite capacity of long-term memory, it is unclear whether throwing a representation out of visual working memory really removes its effects on memory entirely. In this paper we advocate for an approach that examines our ability to erase memory representations from working memory, as well as possible traces that those erased representations leave in long-term memory.

  11. Efficient stochastic thermostatting of path integral molecular dynamics.

    Science.gov (United States)

    Ceriotti, Michele; Parrinello, Michele; Markland, Thomas E; Manolopoulos, David E

    2010-09-28

    The path integral molecular dynamics (PIMD) method provides a convenient way to compute the quantum mechanical structural and thermodynamic properties of condensed phase systems at the expense of introducing an additional set of high frequency normal modes on top of the physical vibrations of the system. Efficiently sampling such a wide range of frequencies provides a considerable thermostatting challenge. Here we introduce a simple stochastic path integral Langevin equation (PILE) thermostat which exploits an analytic knowledge of the free path integral normal mode frequencies. We also apply a recently developed colored noise thermostat based on a generalized Langevin equation (GLE), which automatically achieves a similar, frequency-optimized sampling. The sampling efficiencies of these thermostats are compared with that of the more conventional Nosé-Hoover chain (NHC) thermostat for a number of physically relevant properties of the liquid water and hydrogen-in-palladium systems. In nearly every case, the new PILE thermostat is found to perform just as well as the NHC thermostat while allowing for a computationally more efficient implementation. The GLE thermostat also proves to be very robust delivering a near-optimum sampling efficiency in all of the cases considered. We suspect that these simple stochastic thermostats will therefore find useful application in many future PIMD simulations.

  12. Quivers of Bound Path Algebras and Bound Path Coalgebras

    Directory of Open Access Journals (Sweden)

    Dr. Intan Muchtadi

    2010-09-01

    Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

  13. STUDI KOMPARATIF MODEL PEMBELAJARAN TALKING STICK DAN SNOWBALL THROWING TERHADAP HASIL BELAJAR TEKNOLOGI INFORMASI DAN KOMUNIKASI (TIK SISWA KELAS XI SMA NEGERI 1 SERIRIT TAHUN AJARAN 2015/2016

    Directory of Open Access Journals (Sweden)

    Ni Made Dwi Antari

    2016-10-01

    Abstract TIK learning must have to prepared student’s activities and creativities to obtained the own knowledge by means of learning process. An appropriate learning model election agree with students characteristics would help an success learning. The comparative study research would have to compared both of learning model, to know which model was better. This research aimed to know (1 The influenced about the result of students’ TIK study used Talking stick and Snowball Throwing learning model (2 the highest result of study between Talking stick and Snowball Throwing learning model (3 the students’ response toward Talking stick and Snowball Throwing learning model application. Kind of this research was quasi experiment by Post Test Only with Non Equivalent Control Group Design. The data accumulation done by multiple choice tests to measured cognitive domain and skill test to psychomotor domain. The students’ result study analyzed by prerequisite test was normality test and homogeneity by the result of the three group which normal distribution and homogeneous, continued by hypothesis test used a strip Anova then continued by t-Sheffe The result of one way onova exist a significance influenced on the used of Talking Stick leaarning model, Snowball Throwing and conventional. Because of thee was a significance difereences between each partner. Afterwards, seen from the result average of study  can be concluded the Talking Stick learning model better than the higest result average of study. Meanwhile, the respond of used questionnaire method, the result of Talking stick model questionnaire known 36% very positive responses, 61% positive responses and 3% positive sufficient responses. Then, Snowball Throwing model known 25% very positive responses, 67% positive responses, and 8% positive sufficient responses.   Keywords : The Comparrative Study, TIK, Talking stick, Snowball Throwing, the                    study result,  students’ respond

  14. Fractional path planning and path tracking

    International Nuclear Information System (INIS)

    Melchior, P.; Jallouli-Khlif, R.; Metoui, B.

    2011-01-01

    This paper presents the main results of the application of fractional approach in path planning and path tracking. A new robust path planning design for mobile robot was studied in dynamic environment. The normalized attractive force applied to the robot is based on a fictitious fractional attractive potential. This method allows to obtain robust path planning despite robot mass variation. The danger level of each obstacles is characterized by the fractional order of the repulsive potential of the obstacles. Under these conditions, the robot dynamic behavior was studied by analyzing its X - Y path planning with dynamic target or dynamic obstacles. The case of simultaneously mobile obstacles and target is also considered. The influence of the robot mass variation is studied and the robustness analysis of the obtained path shows the robustness improvement due to the non integer order properties. Pre shaping approach is used to reduce system vibration in motion control. Desired systems inputs are altered so that the system finishes the requested move without residual vibration. This technique, developed by N.C. Singer and W.P.Seering, is used for flexible structure control, particularly in the aerospace field. In a previous work, this method was extended for explicit fractional derivative systems and applied to second generation CRONE control, the robustness was also studied. CRONE (the French acronym of C ommande Robuste d'Ordre Non Entier ) control system design is a frequency-domain based methodology using complex fractional integration.

  15. Degree distribution of shortest path trees and bias of network sampling algorithms

    NARCIS (Netherlands)

    Bhamidi, S.; Goodman, J.A.; Hofstad, van der R.W.; Komjáthy, J.

    2013-01-01

    In this article, we explicitly derive the limiting distribution of the degree distribution of the shortest path tree from a single source on various random network models with edge weights. We determine the power-law exponent of the degree distribution of this tree and compare it to the degree

  16. Degree distribution of shortest path trees and bias of network sampling algorithms

    NARCIS (Netherlands)

    Bhamidi, S.; Goodman, J.A.; Hofstad, van der R.W.; Komjáthy, J.

    2015-01-01

    In this article, we explicitly derive the limiting degree distribution of the shortest path tree from a single source on various random network models with edge weights. We determine the asymptotics of the degree distribution for large degrees of this tree and compare it to the degree distribution

  17. Cis-to- Trans Isomerization of Azobenzene Derivatives Studied with Transition Path Sampling and Quantum Mechanical/Molecular Mechanical Molecular Dynamics.

    Science.gov (United States)

    Muždalo, Anja; Saalfrank, Peter; Vreede, Jocelyne; Santer, Mark

    2018-04-10

    Azobenzene-based molecular photoswitches are becoming increasingly important for the development of photoresponsive, functional soft-matter material systems. Upon illumination with light, fast interconversion between a more stable trans and a metastable cis configuration can be established resulting in pronounced changes in conformation, dipole moment or hydrophobicity. A rational design of functional photosensitive molecules with embedded azo moieties requires a thorough understanding of isomerization mechanisms and rates, especially the thermally activated relaxation. For small azo derivatives considered in the gas phase or simple solvents, Eyring's classical transition state theory (TST) approach yields useful predictions for trends in activation energies or corresponding half-life times of the cis isomer. However, TST or improved theories cannot easily be applied when the azo moiety is part of a larger molecular complex or embedded into a heterogeneous environment, where a multitude of possible reaction pathways may exist. In these cases, only the sampling of an ensemble of dynamic reactive trajectories (transition path sampling, TPS) with explicit models of the environment may reveal the nature of the processes involved. In the present work we show how a TPS approach can conveniently be implemented for the phenomenon of relaxation-isomerization of azobenzenes starting with the simple examples of pure azobenzene and a push-pull derivative immersed in a polar (DMSO) and apolar (toluene) solvent. The latter are represented explicitly at a molecular mechanical (MM) and the azo moiety at a quantum mechanical (QM) level. We demonstrate for the push-pull azobenzene that path sampling in combination with the chosen QM/MM scheme produces the expected change in isomerization pathway from inversion to rotation in going from a low to a high permittivity (explicit) solvent model. We discuss the potential of the simulation procedure presented for comparative calculation of

  18. The effect of low extremity plyometric training on back muscle power of high school throwing event athletes.

    Science.gov (United States)

    Park, Gi Duck; Lee, Joong Chul; Lee, Juri

    2014-01-01

    [Purpose] The physical strength elements required for athletic throwing events include muscle strength, swiftness, agility, speed, flexibility, and physical balance. Although plyometric training and weight training are implemented as representative training methods for improving swiftness and agility, most studies of it have been conducted with players of other sports. [Subjects] The study subjects were 10 throwing event athletes attending K physical education high school. The subjects were randomly assigned to a control group of five subjects and an experimental group of five subjects. To analyze the body composition, an Inbody 3.0 instrument (Biospace, Korea) was used as experimental equipment to measure heights, weight, body fat percentages, and muscle masses and a Biodex system 4.0 (BIODEX, USA) was used to measure isokinetic muscle-joint and lumbar muscle strengths. The plyometric training consisted of 15 techniques out of the training methods introduced in the 'Power up plyometric training'. The plyometric program was implemented without any training load three times per week during daybreak exercises for the experimental group. The number of times and the number of sets were changed over time as follows: three sets of 10 times in the 1st -4th weeks, three sets of 15 times in the 5th-8th weeks, and five sets of 15 times in the 9th-12th weeks. [Results] According to the ANCOVA results of lumbar extensor muscle strength at 60°/sec, the overall reliability of the model was significant. According to the ANCOVA results of lumbar flexor muscle strength at 60°/sec, the overall reliability of the model was significant. [Conclusion] Plyometric training positively affected high school throwing event athletes. To summarize the study findings, the application of plyometric training with high intensity and loads improved the results of athletes who perform highly intensive exercises at normal times.

  19. DIFERENCIAS EN LA CAPACIDAD DE LANZAMIENTO EN FUNCIÓN DE LA ETAPA DEPORTIVA EN JUGADORES DE BALONMANO [Differences in the throwing capacity according to the phases of sporting life in handball players

    Directory of Open Access Journals (Sweden)

    Jesús Rivilla-Garcia

    2010-09-01

    Full Text Available ResumenEl presente estudio pretendió analizar la capacidad de lanzamiento general y específica en función de las etapas de vida deportiva. Con dicho objetivo, ciento seis jugadores de balonmano de diferentes edades y niveles competitivos fueron evaluados en cuatro pruebas de lanzamiento de progresiva especificidad: 1 lanzamiento de balón medicinal pesado (LBMP, 2 lanzamiento de balón medicinal ligero (LBML, 3 velocidad de lanzamiento sin oposición (VSO y 4 velocidad de lanzamiento con oposición (VCO.Los jugadores fueron divididos según su edad (Seiru-lo, 1998: 1ª etapa (16-19 años, 2ª etapa (20-23 años, 3ª etapa (24-28 años y 4ª etapa (más de 29 años. El análisis de diferencias de medias de lanzamiento determinó diferencias significativas entre las cuatro etapas de vida deportiva en los cuatro test de lanzamiento, LBMP (F 3, 102 =34,15; p3, 102=34,76; p 3, 102=55,89; p 3, 102=29,89; pPara todos los grupos la velocidad de lanzamiento fue menor con oposición que sin ella, pero solo se observaron diferencias significativas en la 1ª etapa (20,15±2,34 m·s-1 y 21,41 ±1,70 m·s-1, VCO y VSO, respectivamente; p-1 y 25,92 ±1,67 m·s-1, VCO y VSO, respectivamente; p=0,033; t=2,293; gl=18.En conclusión, la etapa de vida deportiva parece determinante en la evolución de la capacidad de lanzamiento, sobre todo en los test específicos. Igualmente, la oposición del portero parece influir negativamente en la velocidad de lanzamiento, fundamentalmente entre las edades de 16-19 años y 24-28 años.Palabras clave: lanzamiento con balón medicinal, velocidad de lanzamiento, edad, oposición.AbstractThis study aimed to test the general and specific throwing capacity based on the sporting life stages. For that purpose, one hundred and six players of handball of different age and competitive levels were evaluated in four throwing test of progressive specificity: 1 throw with heavy medicine ball (LBMP, 2 throw with light medicine ball (LBML

  20. Feynman's path integrals and Bohm's particle paths

    International Nuclear Information System (INIS)

    Tumulka, Roderich

    2005-01-01

    Both Bohmian mechanics, a version of quantum mechanics with trajectories, and Feynman's path integral formalism have something to do with particle paths in space and time. The question thus arises how the two ideas relate to each other. In short, the answer is, path integrals provide a re-formulation of Schroedinger's equation, which is half of the defining equations of Bohmian mechanics. I try to give a clear and concise description of the various aspects of the situation. (letters and comments)

  1. Re-evaluation of P-T paths across the Himalayan Main Central Thrust

    Science.gov (United States)

    Catlos, E. J.; Harrison, M.; Kelly, E. D.; Ashley, K.; Lovera, O. M.; Etzel, T.; Lizzadro-McPherson, D. J.

    2016-12-01

    The Main Central Thrust (MCT) is the dominant crustal thickening structure in the Himalayas, juxtaposing high-grade Greater Himalayan Crystalline rocks over the lower-grade Lesser Himalaya Formations. The fault is underlain by a 2 to 12-km-thick sequence of deformed rocks characterized by an apparent inverted metamorphic gradient, termed the MCT shear zone. Garnet-bearing rocks sampled from across the MCT along the Marysandi River in central Nepal contain monazite that decrease in age from Early Miocene (ca. 20 Ma) in the hanging wall to Late Miocene-Pliocene (ca. 7 Ma and 3 Ma) towards structurally lower levels in the shear zone. We obtained high-resolution garnet-zoning pressure-temperature (P-T) paths from 11 of the same rocks used for monazite geochronology using a recently-developed semi-automated Gibbs-free-energy-minimization technique. Quartz-in-garnet Raman barometry refined the locations of the paths. Diffusional re-equilibration of garnet zoning in hanging wall samples prevented accurate path determinations from most Greater Himalayan Crystalline samples, but one that shows a bell-shaped Mn zoning profile shows a slight decrease in P (from 8.2 to 7.6kbar) with increase in T (from 590 to 640ºC). Three MCT shear zone samples were modeled: one yields a simple path increasing in both P and T (6 to 7kbar, 540 to 580ºC); the others yield N-shaped paths that occupy similar P-T space (4 to 5.5 kbar, 500 to 560ºC). Five lower lesser Himalaya garnet-bearing rocks were modeled. One yields a path increasing in both P-T (6 to 7 kbar, 525 to 550ºC) but others show either sharp compression/decompression or N-shape paths (within 4.5-6 kbar and 530-580ºC). The lowermost sample decreases in P (5.5 to 5 kbar) over increasing T (540 to 580°C). No progressive change is seen from one type of path to another within the Lesser Himalayan Formations to the MCT zone. The results using the modeling approach yield lower P-T conditions compared to the Gibbs method and lower

  2. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments......We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...

  3. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Directory of Open Access Journals (Sweden)

    Bahri Gjinovci, Kemal Idrizovic, Ognjen Uljevic, Damir Sekulic

    2017-12-01

    Full Text Available There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg, who participated in plyometric- (n = 21, or skill-based-conditioning-program (n = 20. Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM, countermovement jump (CMJ, standing broad jump (SBJ, medicine ball throw, (MBT and 20-m sprint (S20M. All tests were assessed at the study baseline (pre- and at the end of the 12-week programs (post-testing. Two-way ANOVA for repeated measurements showed significant (p<0.05 “Group x Time” effects for all variables but body-height. Plyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes, and improved their performance in S20M (moderate ES; 8%, MBT (very large ES; 25%, CMJ (large ES; 27%, and SBJ (moderate ES; 8%. Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%, SBJ (small ES; 3%, and MBT (large ES; 9%. The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  4. Polygonal-path approximations on the path spaces of quantum-mechanical systems: properties of the polygonal paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1981-01-01

    Properties of the subset of polygonal paths in the Hilbert space H of paths referring to a d-dimensional quantum-mechanical system are examined. Using the reproduction kernel technique we prove that each element of H is approximated by polygonal paths uniformly with respect to the ''norm'' of time-interval partitions. This result will be applied in the second part of the present paper to prove consistency of the uniform polygonal-path extension of the Feynman maps [ru

  5. Joint importance sampling of low-order volumetric scattering

    DEFF Research Database (Denmark)

    Georgiev, Iliyan; Křivánek, Jaroslav; Hachisuka, Toshiya

    2013-01-01

    Central to all Monte Carlo-based rendering algorithms is the construction of light transport paths from the light sources to the eye. Existing rendering approaches sample path vertices incrementally when constructing these light transport paths. The resulting probability density is thus a product...... of the conditional densities of each local sampling step, constructed without explicit control over the form of the final joint distribution of the complete path. We analyze why current incremental construction schemes often lead to high variance in the presence of participating media, and reveal...... that such approaches are an unnecessary legacy inherited from traditional surface-based rendering algorithms. We devise joint importance sampling of path vertices in participating media to construct paths that explicitly account for the product of all scattering and geometry terms along a sequence of vertices instead...

  6. Full cost accounting as a tool for the financial assessment of Pay-As-You-Throw schemes: a case study for the Panorama municipality, Greece.

    Science.gov (United States)

    Karagiannidis, Avraam; Xirogiannopoulou, Anna; Tchobanoglous, George

    2008-12-01

    In the present paper, implementation scenarios of a Pay-As-You-Throw program were developed and analyzed for the first time in Greece. Firstly, the necessary steps for implementing a Pay-As-You-Throw program were determined. A database was developed for the needs of the full cost accounting method, where all financial and waste-production data were inserted, in order to calculate the unit price of charging for four different implementation scenarios of the "polluter-pays" principle. For each scenario, the input in waste management cost was estimated, as well as the total waste charges for households. Finally, a comparative analysis of the results was performed.

  7. BASIC BIOMECHANICAL CHARACTERISTICS OF THE SECOND PHASE (TSUKURI OF JUDO THROWING TECHNIQUE OSOTO GARI

    Directory of Open Access Journals (Sweden)

    Fadil Rexhepi

    2011-09-01

    Full Text Available In a sample of a total of 11 judoists - one was the Tori (thrower, and the other ten were uke (those who were thrown during the performance of throwing technique, was analyzed the second phase of throwing (tsukuri judo technique osoto gari. Tori is an active athlete superior quality (master, body mass = 72 kg, and all the other, who were thrown (uke differ from each other as the weight and height of the body concerned. The average of their body weight was 73.8 kg, which means that it is almost even with body mass of tori. For data collection was used a three-dimensional motion analysis system APAS (Ariel Performance Analysis System. Tsukuri is the phase where occur most actions of reaping leg. The second phase (tsukuri begins when tori detach his right foot and lasts until the beginning of reaping opponent's leg, on which was concentrated its weight (uke's weight. The parameters that describe the effect of the reaping leg in the second phase of technique osoto gari are crucial for the successful execution of this leg technique. For the analysis of the second phase of the throw were selected 14 variables that describe the position of the body and certain body parts of both athletes, velocity parameters of tori's reaping leg and the duration of this phase (time. The role of the tori's standing leg is to maintain a stable position during this phase, while the other leg quickly and in full force acts reaping. The smallest angle of the knee joint of standing leg during the second phase was 130.84 °. Before the moment of reaping, or detachment of uke`s feet from the mat, standing leg has a tendency to extension in the knee joint, which impacts positively on raising the tori's body center of mass. Height tori's body center of mass at the beginning phase was 87.79 cm. As a result of tori's action by pulling onto uke, but little to his left side, the uke`s center of mass at the end of this phase is moved laterally to 6.10 cm. The results show quite

  8. Corrigendum to “Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines” [Agric. Forest Meteorol. 165 (2012) 53–63

    DEFF Research Database (Denmark)

    Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

    2012-01-01

    It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

  9. The Influence of Task Constraints on the Glenohumeral Horizontal Abduction Angle of the Overarm Throw of Novice Throwers

    Science.gov (United States)

    Breslin, Casey M.; Garner, John C.; Rudisill, Mary E.; Parish, Loraine E.; St. Onge, Paul M.; Campbell, Brian J.; Weimar, Wendi H.

    2009-01-01

    This study determines the effects of three baseballs and softballs of different masses (0.113 kg, 0.198 kg, 0.340 kg) and regulation diameters (22.86 and 30.48 cm, respectively) on the glenohumeral horizontal abduction angle of an overarm throw performed by young children who were novice throwers. Glenohumeral horizontal abduction angle was…

  10. Food Ration and Mental Training for the Improvement of the Free Throw Performance in Congolese Beginners Basketball Players

    Science.gov (United States)

    Bouhika, Eddie Janvier; Moussouami, Simplice Innocent; Tsiama Portejoie, Jean Aimé; Bazaba Kayilou, Jean Michel; Moyen, Rachel; Mizere Moungondo, Martin; Maouene, Michel; Mbemba, François

    2016-01-01

    Objective: Through an experimental study, the present work aims at testing the effectiveness of diet and mental imagery on the success of free throw in Congolese beginners Basketball Players. Method: 45 players participated in this experimental study in Brazzaville (Congo). These subjects were divided into 3 groups. Group I (n = 15), made up of…

  11. The Overarm-Throwing Pattern among U-14 ASA Female Softball Players: A Comparative Study of Gender, Culture, and Experience

    Science.gov (United States)

    Petranek, Laura Jones; Barton, Gina V.

    2011-01-01

    A developmental description of overarm-throwing characteristics of U-14 female ASA softball players is presented here. Comparisons were made between these athletes and teens of similar age in the United States (Runion, Roberton, & Langendorfer, 2003) and in Germany (Ehl, Roberton, & Langendorfer, 2005). A majority of the softball players…

  12. Path optimization method for the sign problem

    Directory of Open Access Journals (Sweden)

    Ohnishi Akira

    2018-01-01

    Full Text Available We propose a path optimization method (POM to evade the sign problem in the Monte-Carlo calculations for complex actions. Among many approaches to the sign problem, the Lefschetz-thimble path-integral method and the complex Langevin method are promising and extensively discussed. In these methods, real field variables are complexified and the integration manifold is determined by the flow equations or stochastically sampled. When we have singular points of the action or multiple critical points near the original integral surface, however, we have a risk to encounter the residual and global sign problems or the singular drift term problem. One of the ways to avoid the singular points is to optimize the integration path which is designed not to hit the singular points of the Boltzmann weight. By specifying the one-dimensional integration-path as z = t +if(t(f ϵ R and by optimizing f(t to enhance the average phase factor, we demonstrate that we can avoid the sign problem in a one-variable toy model for which the complex Langevin method is found to fail. In this proceedings, we propose POM and discuss how we can avoid the sign problem in a toy model. We also discuss the possibility to utilize the neural network to optimize the path.

  13. Pulled Motzkin paths

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2010-01-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  14. Pulled Motzkin paths

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J, E-mail: rensburg@yorku.c [Department of Mathematics and Statistics, York University, Toronto, ON, M3J 1P3 (Canada)

    2010-08-20

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) {yields} f as f {yields} {infinity}, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) {yields} 2f as f {yields} {infinity}, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  15. Pulled Motzkin paths

    Science.gov (United States)

    Janse van Rensburg, E. J.

    2010-08-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  16. Computing Diffeomorphic Paths for Large Motion Interpolation.

    Science.gov (United States)

    Seo, Dohyung; Jeffrey, Ho; Vemuri, Baba C

    2013-06-01

    In this paper, we introduce a novel framework for computing a path of diffeomorphisms between a pair of input diffeomorphisms. Direct computation of a geodesic path on the space of diffeomorphisms Diff (Ω) is difficult, and it can be attributed mainly to the infinite dimensionality of Diff (Ω). Our proposed framework, to some degree, bypasses this difficulty using the quotient map of Diff (Ω) to the quotient space Diff ( M )/ Diff ( M ) μ obtained by quotienting out the subgroup of volume-preserving diffeomorphisms Diff ( M ) μ . This quotient space was recently identified as the unit sphere in a Hilbert space in mathematics literature, a space with well-known geometric properties. Our framework leverages this recent result by computing the diffeomorphic path in two stages. First, we project the given diffeomorphism pair onto this sphere and then compute the geodesic path between these projected points. Second, we lift the geodesic on the sphere back to the space of diffeomerphisms, by solving a quadratic programming problem with bilinear constraints using the augmented Lagrangian technique with penalty terms. In this way, we can estimate the path of diffeomorphisms, first, staying in the space of diffeomorphisms, and second, preserving shapes/volumes in the deformed images along the path as much as possible. We have applied our framework to interpolate intermediate frames of frame-sub-sampled video sequences. In the reported experiments, our approach compares favorably with the popular Large Deformation Diffeomorphic Metric Mapping framework (LDDMM).

  17. Path Expressions

    Science.gov (United States)

    1975-06-01

    Traditionally, synchronization of concurrent processes is coded in line by operations on semaphores or similar objects. Path expressions move the...discussion about a variety of synchronization primitives . An analysis of their relative power is found in [3]. Path expressions do not introduce yet...another synchronization primitive . A path expression relates to such primitives as a for- or while-statement of an ALGOL-like language relates to a JUMP

  18. Neutron capture studies with a short flight path

    Science.gov (United States)

    Walter, Stephan; Heil, Michael; Käppeler, Franz; Plag, Ralf; Reifarth, René

    The time of flight (TOF) method is an important tool for the experimental determination of neu- tron capture cross sections which are needed for s-process nucleosynthesis in general, and for analyses of branchings in the s-process reaction path in particular. So far, sample masses of at least several milligrams are required to compensate limitations in the currently available neutron fluxes. This constraint leads to unacceptable backgrounds for most of the relevant unstable branch point nuclei, due to the decay activity of the sample. A possible solution has been proposed by the NCAP project at the University of Frankfurt. A first step in this direction is reported here, which aims at enhancing the sensitivity of the Karlsruhe TOF array by reducing the neutron flight path to only a few centimeters. Though sample masses in the microgram regime can be used by this approach, the increase in neutron flux has to be paid by a higher background from the prompt flash related to neutron production. Test measurements with Au samples are reported.

  19. Statistical Symbolic Execution with Informed Sampling

    Science.gov (United States)

    Filieri, Antonio; Pasareanu, Corina S.; Visser, Willem; Geldenhuys, Jaco

    2014-01-01

    Symbolic execution techniques have been proposed recently for the probabilistic analysis of programs. These techniques seek to quantify the likelihood of reaching program events of interest, e.g., assert violations. They have many promising applications but have scalability issues due to high computational demand. To address this challenge, we propose a statistical symbolic execution technique that performs Monte Carlo sampling of the symbolic program paths and uses the obtained information for Bayesian estimation and hypothesis testing with respect to the probability of reaching the target events. To speed up the convergence of the statistical analysis, we propose Informed Sampling, an iterative symbolic execution that first explores the paths that have high statistical significance, prunes them from the state space and guides the execution towards less likely paths. The technique combines Bayesian estimation with a partial exact analysis for the pruned paths leading to provably improved convergence of the statistical analysis. We have implemented statistical symbolic execution with in- formed sampling in the Symbolic PathFinder tool. We show experimentally that the informed sampling obtains more precise results and converges faster than a purely statistical analysis and may also be more efficient than an exact symbolic analysis. When the latter does not terminate symbolic execution with informed sampling can give meaningful results under the same time and memory limits.

  20. Zero-Slack, Noncritical Paths

    Science.gov (United States)

    Simons, Jacob V., Jr.

    2017-01-01

    The critical path method/program evaluation and review technique method of project scheduling is based on the importance of managing a project's critical path(s). Although a critical path is the longest path through a network, its location in large projects is facilitated by the computation of activity slack. However, logical fallacies in…

  1. The Throw-and-Catch Model of Human Gait: Evidence from Coupling of Pre-Step Postural Activity and Step Location

    Science.gov (United States)

    Bancroft, Matthew J.; Day, Brian L.

    2016-01-01

    Postural activity normally precedes the lift of a foot from the ground when taking a step, but its function is unclear. The throw-and-catch hypothesis of human gait proposes that the pre-step activity is organized to generate momentum for the body to fall ballistically along a specific trajectory during the step. The trajectory is appropriate for the stepping foot to land at its intended location while at the same time being optimally placed to catch the body and regain balance. The hypothesis therefore predicts a strong coupling between the pre-step activity and step location. Here we examine this coupling when stepping to visually-presented targets at different locations. Ten healthy, young subjects were instructed to step as accurately as possible onto targets placed in five locations that required either different step directions or different step lengths. In 75% of trials, the target location remained constant throughout the step. In the remaining 25% of trials, the intended step location was changed by making the target jump to a new location 96 ms ± 43 ms after initiation of the pre-step activity, long before foot lift. As predicted by the throw-and-catch hypothesis, when the target location remained constant, the pre-step activity led to body momentum at foot lift that was coupled to the intended step location. When the target location jumped, the pre-step activity was adjusted (median latency 223 ms) and prolonged (on average by 69 ms), which altered the body’s momentum at foot lift according to where the target had moved. We conclude that whenever possible the coupling between the pre-step activity and the step location is maintained. This provides further support for the throw-and-catch hypothesis of human gait. PMID:28066208

  2. The Throw-and-Catch Model of Human Gait: Evidence from Coupling of Pre-Step Postural Activity and Step Location.

    Science.gov (United States)

    Bancroft, Matthew J; Day, Brian L

    2016-01-01

    Postural activity normally precedes the lift of a foot from the ground when taking a step, but its function is unclear. The throw-and-catch hypothesis of human gait proposes that the pre-step activity is organized to generate momentum for the body to fall ballistically along a specific trajectory during the step. The trajectory is appropriate for the stepping foot to land at its intended location while at the same time being optimally placed to catch the body and regain balance. The hypothesis therefore predicts a strong coupling between the pre-step activity and step location. Here we examine this coupling when stepping to visually-presented targets at different locations. Ten healthy, young subjects were instructed to step as accurately as possible onto targets placed in five locations that required either different step directions or different step lengths. In 75% of trials, the target location remained constant throughout the step. In the remaining 25% of trials, the intended step location was changed by making the target jump to a new location 96 ms ± 43 ms after initiation of the pre-step activity, long before foot lift. As predicted by the throw-and-catch hypothesis, when the target location remained constant, the pre-step activity led to body momentum at foot lift that was coupled to the intended step location. When the target location jumped, the pre-step activity was adjusted (median latency 223 ms) and prolonged (on average by 69 ms), which altered the body's momentum at foot lift according to where the target had moved. We conclude that whenever possible the coupling between the pre-step activity and the step location is maintained. This provides further support for the throw-and-catch hypothesis of human gait.

  3. Another Look at the Mechanisms of Hydride Transfer Enzymes with Quantum and Classical Transition Path Sampling.

    Science.gov (United States)

    Dzierlenga, Michael W; Antoniou, Dimitri; Schwartz, Steven D

    2015-04-02

    The mechanisms involved in enzymatic hydride transfer have been studied for years, but questions remain due, in part, to the difficulty of probing the effects of protein motion and hydrogen tunneling. In this study, we use transition path sampling (TPS) with normal mode centroid molecular dynamics (CMD) to calculate the barrier to hydride transfer in yeast alcohol dehydrogenase (YADH) and human heart lactate dehydrogenase (LDH). Calculation of the work applied to the hydride allowed for observation of the change in barrier height upon inclusion of quantum dynamics. Similar calculations were performed using deuterium as the transferring particle in order to approximate kinetic isotope effects (KIEs). The change in barrier height in YADH is indicative of a zero-point energy (ZPE) contribution and is evidence that catalysis occurs via a protein compression that mediates a near-barrierless hydride transfer. Calculation of the KIE using the difference in barrier height between the hydride and deuteride agreed well with experimental results.

  4. Peningkatan Hasil Belajar Siswa Materi Usaha Mempertahankan Republik Indonesia Melalui Model Pembelajaran Snowball Throwing Pada Kelas IX.2 SMP Negeri Muara Beliti

    Directory of Open Access Journals (Sweden)

    Holili Holili

    2017-10-01

    Full Text Available This study aims to improve student learning outcomes of class IX.2 State Junior High School Muara Beliti on the material business to defend the Republic of Indonesia by using the Snowball throwing learning. The research method used is Classroom Action Research. The study was conducted in two cycles with each model cycle following the procedure: planning, action, observation, and reflection. The action of two cycles resulted in improving the quality of learning and improving the learning outcomes, the average completeness of students' learning cycle one 68.55% completeness 61.29%. Cycle two averages 80.1% completeness 90%. The end result of the two cycle action succeeded in improving the IPS learning outcomes. Keywords: Learning Outcome, Snowball throwing   http://dx.doi.org/10.17977/um022v2i12017p025

  5. Tornado intensity estimated from damage path dimensions.

    Science.gov (United States)

    Elsner, James B; Jagger, Thomas H; Elsner, Ian J

    2014-01-01

    The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1) for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  6. Tornado intensity estimated from damage path dimensions.

    Directory of Open Access Journals (Sweden)

    James B Elsner

    Full Text Available The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1 for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93 [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  7. Path Creation, Path Dependence and Breaking Away from the Path: Re-Examining the Case of Nokia

    OpenAIRE

    Wang, Jens; Hedman, Jonas; Tuunainen, Virpi Kristiina

    2016-01-01

    The explanation of how and why firms succeed or fail is a recurrent research challenge. This is particularly important in the context of technological innovations. We focus on the role of historical events and decisions in explaining such success and failure. Using a case study of Nokia, we develop and extend a multi-layer path dependence framework. We identify four layers of path dependence: technical, strategic and leadership, organizational, and external collaboration. We show how path dep...

  8. Path-dependent functions

    International Nuclear Information System (INIS)

    Khrapko, R.I.

    1985-01-01

    A uniform description of various path-dependent functions is presented with the help of expansion of the type of the Taylor series. So called ''path-integrals'' and ''path-tensor'' are introduced which are systems of many-component quantities whose values are defined for arbitrary paths in coordinated region of space in such a way that they contain a complete information on the path. These constructions are considered as elementary path-dependent functions and are used instead of power monomials in the usual Taylor series. Coefficients of such an expansion are interpreted as partial derivatives dependent on the order of the differentiations or else as nonstandard cavariant derivatives called two-point derivatives. Some examples of pathdependent functions are presented.Space curvature tensor is considered whose geometrica properties are determined by the (non-transitive) translator of parallel transport of a general type. Covariant operation leading to the ''extension'' of tensor fiels is pointed out

  9. Diferencias en la distancia de lanzamiento y velocidad de balón según el puesto específico en jugadores de balonmano sub-18. (Differences in the throwing distance and ball velocity by playing position in under-18 handball players.

    Directory of Open Access Journals (Sweden)

    Javier Sampedro Molinuelo

    2011-01-01

    Full Text Available ResumenEl presente estudio ha analizado las diferencias entre puestos específicos ofensivos en la distancia delanzamiento con balón medicinal pesado y liviano y en la velocidad de lanzamiento con y sin oposición en jugadores en formación. Para ello, cincuenta y ocho jugadores realizaron pruebas de progresiva especificidad: lanzamiento con balón medicinal pesado (LBMP y ligero (LBML, velocidad de lanzamiento sin (VL y con oposición (VLO.VLO fue menor a VL en todos los puestos específicos, con diferencias significativas en los jugadores laterales (p AbstractThis study aims to analyze the differences in throwing distance with overweight ball and throwing velocity without and with opposition according to the playing positions in trainees handball players. For this purpose, fifty-eight players were assessed in four specific progress throwing situations: throwing with heavy medicinal ball (THMB and light medicinal ball (TLMB, throwing velocity without (TV and with opposition (TVO.TVO was less than TV in all playing positions, with significant differences in back (p doi:10.5232/ricyde2011.02202

  10. Dynamic Path Analysis in Life-Course Epidemiology

    DEFF Research Database (Denmark)

    Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.

    2011-01-01

    it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... by other variables) and indirect effects (mediated through other variables). This is illustrated by examining the associations between repeated measurements of body mass index (BMI) and systolic blood pressure (SBP) and the risk of CHD in a sample of Danish men between 1976 and 2006. The effect of baseline...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie...

  11. Numerical simulation of the throwing power of cathodic prevention applied to marine reinforced concrete piles by means of sacrificial anodes

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Luca; Redaelli, Elena [Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica ' G. Natta' , Via Mancinelli, 7, 20131 Milan (Italy)

    2004-07-01

    The paper deals with the determination of current and potential distribution in reinforced concrete elements partially submerged in seawater aimed at predicting the throwing power of cathodic prevention applied by means of sacrificial anodes. Previous laboratory studies carried out on reinforced concrete columns 15 cm x 15 cm x 120 cm showed that the use of sacrificial anodes placed in the solution at the bottom of the column could provide protection of corroding steel bars in the emerged part of the pile up to about 60 cm from the water level. However, if sacrificial anodes were applied when the concrete was chloride free and steel bars were still passive, even the highest bar, placed at 1 m from the level of water, was protected. This is due to the higher polarizability of passive steel, that makes the throwing power of cathodic prevention higher compared to that of cathodic protection. In order to extend the results obtained on small-scale specimens to elements of higher dimensions, numerical simulations of current and potential distribution were carried out. Two-dimensional models were set up of reinforced concrete piles containing steel bars at different heights protected with sacrificial anodes placed in the water in which they were partially submerged. Boundary conditions describing the electrochemical behaviour of bars were obtained from polarisation curves measured on the previously mentioned columns. Values of concrete conductivity at different heights from the water level were also obtained from those tests. Several cases were considered, representative of conditions differing in electrochemical behaviour of steel bars, dimensions of element, position of sacrificial anodes. The paper discusses the results obtained from the models and compares them in terms of the throwing power that can be reached by using sacrificial anodes immersed in the seawater to protect reinforcing steel bars in the emerged part of a pile. (authors)

  12. Assist-as-needed robotic trainer based on reinforcement learning and its application to dart-throwing.

    Science.gov (United States)

    Obayashi, Chihiro; Tamei, Tomoya; Shibata, Tomohiro

    2014-05-01

    This paper proposes a novel robotic trainer for motor skill learning. It is user-adaptive inspired by the assist-as-needed principle well known in the field of physical therapy. Most previous studies in the field of the robotic assistance of motor skill learning have used predetermined desired trajectories, and it has not been examined intensively whether these trajectories were optimal for each user. Furthermore, the guidance hypothesis states that humans tend to rely too much on external assistive feedback, resulting in interference with the internal feedback necessary for motor skill learning. A few studies have proposed a system that adjusts its assistive strength according to the user's performance in order to prevent the user from relying too much on the robotic assistance. There are, however, problems in these studies, in that a physical model of the user's motor system is required, which is inherently difficult to construct. In this paper, we propose a framework for a robotic trainer that is user-adaptive and that neither requires a specific desired trajectory nor a physical model of the user's motor system, and we achieve this using model-free reinforcement learning. We chose dart-throwing as an example motor-learning task as it is one of the simplest throwing tasks, and its performance can easily be and quantitatively measured. Training experiments with novices, aiming at maximizing the score with the darts and minimizing the physical robotic assistance, demonstrate the feasibility and plausibility of the proposed framework. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Multi-AGV path planning with double-path constraints by using an improved genetic algorithm.

    Directory of Open Access Journals (Sweden)

    Zengliang Han

    Full Text Available This paper investigates an improved genetic algorithm on multiple automated guided vehicle (multi-AGV path planning. The innovations embody in two aspects. First, three-exchange crossover heuristic operators are used to produce more optimal offsprings for getting more information than with the traditional two-exchange crossover heuristic operators in the improved genetic algorithm. Second, double-path constraints of both minimizing the total path distance of all AGVs and minimizing single path distances of each AGV are exerted, gaining the optimal shortest total path distance. The simulation results show that the total path distance of all AGVs and the longest single AGV path distance are shortened by using the improved genetic algorithm.

  14. Conceptual Soundness, Metric Development, Benchmarking, and Targeting for PATH Subprogram Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Mosey. G.; Doris, E.; Coggeshall, C.; Antes, M.; Ruch, J.; Mortensen, J.

    2009-01-01

    The objective of this study is to evaluate the conceptual soundness of the U.S. Department of Housing and Urban Development (HUD) Partnership for Advancing Technology in Housing (PATH) program's revised goals and establish and apply a framework to identify and recommend metrics that are the most useful for measuring PATH's progress. This report provides an evaluative review of PATH's revised goals, outlines a structured method for identifying and selecting metrics, proposes metrics and benchmarks for a sampling of individual PATH programs, and discusses other metrics that potentially could be developed that may add value to the evaluation process. The framework and individual program metrics can be used for ongoing management improvement efforts and to inform broader program-level metrics for government reporting requirements.

  15. Arremessar por cima do ombro e a distância percorrida pelo implemento Overarm throw and the distance traveled by the implement

    Directory of Open Access Journals (Sweden)

    Samuel Bento da Silva

    2009-12-01

    Full Text Available A habilidade de arremessar por cima do ombro tem sido bastante estudada, observando-se a velocidade do implemento, porém enquanto muitas tarefas têm como objetivo arremessar o mais longe possível, a distância percorrida pelo objeto ainda não tem sido investigada. O objetivo deste estudo foi verificar se existe relação entre o estágio de desenvolvimento motor nesta habilidade e a distância percorrida pelo implemento e observar diferenças entre os gêneros masculino e feminino; 50 crianças, com idade entre 7-8 anos, de ambos os gêneros, procedentes de Piracicaba - SP foram analisadas enquanto arremessavam uma bola de tênis de campo, o mais longe possível. Cada criança realizou três arremessos intercalados e foi filmada com duas câmeras mini DV, tanto em vista lateral quanto posterior, enquanto arremessava. O nível de desenvolvimento das crianças foi classificado, utilizando-se uma sequência de desenvolvimento e a distância percorrida pela bola foi registrada. Foi encontrada correlação significativa entre o nível do desenvolvimento e a distância atingida. Diferenças entre os gêneros foram observadas: os meninos encontravam-se em níveis desenvolvimentais mais avançados em todas as ações e alcançaram maiores distâncias. Assim, o nível de desenvolvimento desta habilidade mostrou-se importante para o alcance de seu objetivo (arremessar mais longe. Sugere-se que o nível de habilidade é influenciado pelo meio ambiente e que oportunidades de movimento devem ser providenciadas para auxiliar o desenvolvimento integral da criança.Overarm throwing skill has been widely studied regarding the farthest throwing distance analysing the velocity of the implement; however the object's distance has not been investigated. The aim of this study was to verify if there is a relationship between the skill development and the distance reached by the object and to observe differences between genders. Fifty children, ages 7-8 years, both

  16. Integral transforms of the quantum mechanical path integral: Hit function and path-averaged potential

    Science.gov (United States)

    Edwards, James P.; Gerber, Urs; Schubert, Christian; Trejo, Maria Anabel; Weber, Axel

    2018-04-01

    We introduce two integral transforms of the quantum mechanical transition kernel that represent physical information about the path integral. These transforms can be interpreted as probability distributions on particle trajectories measuring respectively the relative contribution to the path integral from paths crossing a given spatial point (the hit function) and the likelihood of values of the line integral of the potential along a path in the ensemble (the path-averaged potential).

  17. Blast tests of expedient shelters in the DICE THROW event

    International Nuclear Information System (INIS)

    Kearny, C.H.; Chester, C.V.

    1978-03-01

    To determine the worst blast environments that eight types of expedient shelters can withstand, we subjected a total of 18 shelters to the 1-kiloton blast effects of Defense Nuclear Agency's DICE THROW main event. These expedient shelters included two Russian and two Chinese types. The best shelter tested was a Small-Pole Shelter that had a box-like room of Russian design with ORNL-designed expedient blast entries and blast doors added. It was undamaged at the 53-psi peak overpressure range; the pressure rise inside was only 1.5 psi. An unmodified Russian Pole-Covered Trench Shelter was badly damaged at 6.8 psi. A Chinese ''Man'' Shelter, which skillfully uses very small poles to attain protective earth arching, survived 20 psi, undamaged. Two types of expedient shelters built of materials found in and around most American homes gave good protection at overpressures up to about 6 psi. Rug-Covered Trench Shelters were proved unsatisfactory. Water storage pits lined with ordinary plastic trash bags were proven practical at up to 53 psi, as were triangular expedient blast doors made of poles

  18. Path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-08-20

    An ensemble-based approach is developed to conduct optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where an ensemble of deterministic predictions is used to model and quantify uncertainty. In an operational setting, much about dynamics, topography, and forcing of the ocean environment is uncertain. To address this uncertainty, the flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each of the resulting realizations of the uncertain current field, we predict the path that minimizes the travel time by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of the sampling strategy and to develop insight into extensions dealing with general circulation ocean models. In particular, the ensemble method enables us to perform a statistical analysis of travel times and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  19. Strength Determinants of Jump Height in the Jump Throw Movement in Women Handball Players.

    Science.gov (United States)

    McGhie, David; Østerås, Sindre; Ettema, Gertjan; Paulsen, Gøran; Sandbakk, Øyvind

    2018-06-08

    McGhie, D, Østerås, S, Ettema, G, Paulsen, G, and Sandbakk, Ø. Strength determinants of jump height in the jump throw movement in women handball players. J Strength Cond Res XX(X): 000-000, 2018-The purpose of the study was to improve the understanding of the strength demands of a handball-specific jump through examining the associations between jump height in a jump throw jump (JTJ) and measures of lower-body maximum strength and impulse in handball players. For comparison, whether the associations between jump height and strength differed between the JTJ and the customarily used countermovement jump (CMJ) was also examined. Twenty women handball players from a Norwegian top division club participated in the study. Jump height was measured in the JTJ and in unilateral and bilateral CMJ. Lower-body strength (maximum isometric force, one-repetition maximum [1RM], impulse at ∼60% and ∼35% 1RM) was measured in seated leg press. The associations between jump height and strength were assessed with correlation analyses and t-tests of dependent r's were performed to determine if correlations differed between jump tests. Only impulse at ∼35% 1RM correlated significantly with JTJ height (p jump height and strength were significantly weaker in the JTJ than in both CMJ tests for all strength measures (p = 0.001-0.044) except one. Maximum strength and impulse at ∼60% 1RM did not seem to sufficiently capture the capabilities associated with JTJ height, highlighting the importance of employing tests targeting performance-relevant neuromuscular characteristics when assessing jump-related strength in handball players. Further, CMJ height seemed to represent a wider range of strength capabilities and care should be taken when using it as a proxy for handball-specific movements.

  20. Girsanov reweighting for path ensembles and Markov state models

    Science.gov (United States)

    Donati, L.; Hartmann, C.; Keller, B. G.

    2017-06-01

    The sensitivity of molecular dynamics on changes in the potential energy function plays an important role in understanding the dynamics and function of complex molecules. We present a method to obtain path ensemble averages of a perturbed dynamics from a set of paths generated by a reference dynamics. It is based on the concept of path probability measure and the Girsanov theorem, a result from stochastic analysis to estimate a change of measure of a path ensemble. Since Markov state models (MSMs) of the molecular dynamics can be formulated as a combined phase-space and path ensemble average, the method can be extended to reweight MSMs by combining it with a reweighting of the Boltzmann distribution. We demonstrate how to efficiently implement the Girsanov reweighting in a molecular dynamics simulation program by calculating parts of the reweighting factor "on the fly" during the simulation, and we benchmark the method on test systems ranging from a two-dimensional diffusion process and an artificial many-body system to alanine dipeptide and valine dipeptide in implicit and explicit water. The method can be used to study the sensitivity of molecular dynamics on external perturbations as well as to reweight trajectories generated by enhanced sampling schemes to the original dynamics.

  1. Pricing of path dependent derivatives with discretely monitored underlying assets

    Science.gov (United States)

    Choi, Hyomin

    This dissertation presents two different approaches to path dependent option pricing with discrete sampling. Provided the underlying asset of a path dependent derivative contract follows an affine process, we use the forward characteristic method to evaluate its fair price. Our study shows that the valuation method is numerically accessible as long as the contract payoff is a linear combination of log return of its underlying asset price. We compute various examples of such contracts and give contract-tailored formulas that we use in these examples. In the second part, we consider variance options under stochastic volatility model. We analyze the difference between variance option prices with discrete and continuous sampling as a function of N, the number of observations made in the former. We find the series expansion of the difference with respect to 1/N and find its leading term. By adding this leading term to the value of continuously sampled variance option, we obtain a simple and well-understood approximation of discretely sample variance option price.

  2. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    In traffic research, management, and planning a number of path-based analyses are heavily used, e.g., for computing turn-times, evaluating green waves, or studying traffic flow. These analyses require retrieving the trajectories that follow the full path being analyzed. Existing path queries cannot...... sufficiently support such path-based analyses because they retrieve all trajectories that touch any edge in the path. In this paper, we define and formalize the strict path query. This is a novel query type tailored to support path-based analysis, where trajectories must follow all edges in the path...... a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set...

  3. Cyclic fatigue resistance of R-Pilot, HyFlex EDM and PathFile nickel-titanium glide path files in artificial canals with double (S-shaped) curvature.

    Science.gov (United States)

    Uslu, G; Özyürek, T; Yılmaz, K; Gündoğar, M

    2018-05-01

    To examine the cyclic fatigue resistances of R-Pilot, HyFlex EDM and PathFile NiTi glide path files in S-shaped artificial canals. Twenty R-Pilot (12.5/.04), 20 HyFlex EDM (10/.05) and 20 PathFile (19/.02) single-file glide path files were included. Sixty files (n: 20/each) were subjected to static cyclic fatigue testing using double-curved canals until fracture occurred (TF). The number of cycles to fracture (NCF) was calculated by multiplying the rpm value by the TF. The length of the fractured fragment (FL) was determined by a digital microcaliper. Six samples of fractured files (n: 2/each) were examined by SEM to determine the fracture mode. The NCF and the FL data were analysed using one-way anova, post hoc Tamhane and Kruskal-Wallis tests using SPPS 21 software. The significance level was set at 5%. In the double-curved canal, all the files fractured first in the apical curvature and then in the coronal curvature. The NCF values revealed that the R-Pilot had the greatest cyclic fatigue resistance, followed by the HyFlex EDM and PathFile in both the apical and coronal curvatures (P < 0.05). R-Pilot NiTi glide path files, used in a reciprocating motion, had the greatest cyclic fatigue resistance amongst the tested NiTi glide path files in an artificial S-shaped canal. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  4. Stresses in the plantar region for long- and short-range throws in women basketball players.

    Science.gov (United States)

    Pau, Massimiliano; Ciuti, Carla

    2013-01-01

    This study aimed to assess plantar pressure pattern modifications caused by short- and long-distance shots in women basketball players. To this end, 24 experienced national- and regional-level basketball players performed 3 trials of 4 technical gestures (free throw, jump stop shot, three-point shot and lay-up) barefoot on a pressure platform placed in fixed positions on the court. Raw data were processed to calculate location and magnitude of pressure peaks in three sub-regions (forefoot, midfoot and rearfoot), and the increase ratio was calculated relative to plantar pressure measured during a static bipedal and unipedal upright stance. The results showed significant increases (ptraining and rehabilitation protocols.

  5. Effects of Relaxing and Arousing Music during Imagery Training on Dart-Throwing Performance, Physiological Arousal Indices, and Competitive State Anxiety.

    Science.gov (United States)

    Kuan, Garry; Morris, Tony; Kueh, Yee Cheng; Terry, Peter C

    2018-01-01

    Music that is carefully selected to match the requirements of activities and the characteristics of individuals has been shown to produce significant impacts on performance enhancement (Priest et al., 2004). There is also evidence that music can enhance imagery (Grocke and Wigram, 2007), although few studies have investigated the effects of music on imagery in the context of sport skills. In the present study, the effects of relaxing and arousing music during imagery on dart-throwing performance, physiological arousal indices, and competitive state anxiety, were investigated among 63 novice dart throwers. Participants had moderate-to-high imagery ability and were randomly assigned to unfamiliar relaxing music (URM), unfamiliar arousing music (UAM), or no music (NM) groups. Performance was assessed by 40 dart throws at a concentric circles dartboard before and after 12 imagery sessions over 4 weeks. Measures of galvanic skin response (GSR), peripheral temperature (PT), and heart rate (HR) were taken during imagery sessions 1 and 12, and the Competitive State Anxiety Inventory-2 Revised (CSAI-2R) was administered prior to the pre- and post-intervention performance task. Dart-throwing gain scores were significantly higher for URM than for UAM and NM, with no significant difference between UAM and NM (URM = 37.24 ± 5.66, UAM = 17.57 ± 5.30, and NM = 13.19 ± 6.14, F 2,62 = 5.03, p = 0.01, η 2 = 0.14). GSR, PT, and HR reflected lower arousal for URM than for UAM or NM. Significant decreases in somatic anxiety were evident for URM and UAM but not NM. Significant decreases in cognitive anxiety were evident for URM and NM but not UAM. Significant increases in self-confidence were evident for URM but not UAM or NM. Performance improved in all three conditions but URM was associated with the largest performance gain, the lowest physiological indices of arousal, and the most positive CSAI-2R profiles. Listening to relaxing music during imagery may have benefits for

  6. Effects of Relaxing and Arousing Music during Imagery Training on Dart-Throwing Performance, Physiological Arousal Indices, and Competitive State Anxiety

    Directory of Open Access Journals (Sweden)

    Garry Kuan

    2018-02-01

    Full Text Available Music that is carefully selected to match the requirements of activities and the characteristics of individuals has been shown to produce significant impacts on performance enhancement (Priest et al., 2004. There is also evidence that music can enhance imagery (Grocke and Wigram, 2007, although few studies have investigated the effects of music on imagery in the context of sport skills. In the present study, the effects of relaxing and arousing music during imagery on dart-throwing performance, physiological arousal indices, and competitive state anxiety, were investigated among 63 novice dart throwers. Participants had moderate-to-high imagery ability and were randomly assigned to unfamiliar relaxing music (URM, unfamiliar arousing music (UAM, or no music (NM groups. Performance was assessed by 40 dart throws at a concentric circles dartboard before and after 12 imagery sessions over 4 weeks. Measures of galvanic skin response (GSR, peripheral temperature (PT, and heart rate (HR were taken during imagery sessions 1 and 12, and the Competitive State Anxiety Inventory-2 Revised (CSAI-2R was administered prior to the pre- and post-intervention performance task. Dart-throwing gain scores were significantly higher for URM than for UAM and NM, with no significant difference between UAM and NM (URM = 37.24 ± 5.66, UAM = 17.57 ± 5.30, and NM = 13.19 ± 6.14, F2,62 = 5.03, p = 0.01, η2 = 0.14. GSR, PT, and HR reflected lower arousal for URM than for UAM or NM. Significant decreases in somatic anxiety were evident for URM and UAM but not NM. Significant decreases in cognitive anxiety were evident for URM and NM but not UAM. Significant increases in self-confidence were evident for URM but not UAM or NM. Performance improved in all three conditions but URM was associated with the largest performance gain, the lowest physiological indices of arousal, and the most positive CSAI-2R profiles. Listening to relaxing music during imagery may have benefits for

  7. Path integration quantization

    International Nuclear Information System (INIS)

    DeWitt-Morette, C.

    1983-01-01

    Much is expected of path integration as a quantization procedure. Much more is possible if one recognizes that path integration is at the crossroad of stochastic and differential calculus and uses the full power of both stochastic and differential calculus in setting up and computing path integrals. In contrast to differential calculus, stochastic calculus has only comparatively recently become an instrument of thought. It has nevertheless already been used in a variety of challenging problems, for instance in the quantization problem. The author presents some applications of the stochastic scheme. (Auth.)

  8. Injuries to the shoulder in the throwing athlete. Part two: evaluation/treatment.

    Science.gov (United States)

    Meister, K

    2000-01-01

    In part one of this three-part series (March/April 2000), I concentrated on summarizing the biomechanics of the normal throwing shoulder and the pathophysiology of injury. A classification of injury was presented that was based on the principles contained in that article. Part two of this series will focus on the evaluation and treatment of injuries, expanded from an understanding of the principles learned in part one. The ability to perform a skillful examination, and thus develop an accurate diagnosis, is the foundation for treatment. Fortunately, many difficulties encountered in a thrower's shoulder can be treated with a nonoperative approach. However, in instances where conservative measures fail, an improved understanding of the pathophysiology of injury and the development of improved surgical techniques are leading to more accurate diagnoses and more successful rates of return of the athlete to a premorbid level of activity.

  9. UMAPRM: Uniformly sampling the medial axis

    KAUST Repository

    Yeh, Hsin-Yi Cindy

    2014-05-01

    © 2014 IEEE. Maintaining clearance, or distance from obstacles, is a vital component of successful motion planning algorithms. Maintaining high clearance often creates safer paths for robots. Contemporary sampling-based planning algorithms That utilize The medial axis, or The set of all points equidistant To Two or more obstacles, produce higher clearance paths. However, They are biased heavily Toward certain portions of The medial axis, sometimes ignoring parts critical To planning, e.g., specific Types of narrow passages. We introduce Uniform Medial Axis Probabilistic RoadMap (UMAPRM), a novel planning variant That generates samples uniformly on The medial axis of The free portion of Cspace. We Theoretically analyze The distribution generated by UMAPRM and show its uniformity. Our results show That UMAPRM\\'s distribution of samples along The medial axis is not only uniform but also preferable To other medial axis samplers in certain planning problems. We demonstrate That UMAPRM has negligible computational overhead over other sampling Techniques and can solve problems The others could not, e.g., a bug Trap. Finally, we demonstrate UMAPRM successfully generates higher clearance paths in The examples.

  10. Sampling of ore

    International Nuclear Information System (INIS)

    Boehme, R.C.; Nicholas, B.L.

    1987-01-01

    This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

  11. Reparametrization in the path integral

    International Nuclear Information System (INIS)

    Storchak, S.N.

    1983-01-01

    The question of the invariance of a measure in the n-dimensional path integral under the path reparametrization is considered. The non-invariance of the measure through the jacobian is suggeste. After the path integral reparametrization the representatioq for the Green's function of the Hamilton operator in terms of the path integral with the classical Hamiltonian has been obtained

  12. Unique Path Partitions

    DEFF Research Database (Denmark)

    Bessenrodt, Christine; Olsson, Jørn Børling; Sellers, James A.

    2013-01-01

    We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions.......We give a complete classification of the unique path partitions and study congruence properties of the function which enumerates such partitions....

  13. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-01-06

    An ensemble-based approach is developed to conduct time-optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where a set deterministic predictions is used to model and quantify uncertainty in the predictions. In the operational setting, much about dynamics, topography and forcing of the ocean environment is uncertain, and as a result a single path produced by a model simulation has limited utility. To overcome this limitation, we rely on a finitesize ensemble of deterministic forecasts to quantify the impact of variability in the dynamics. The uncertainty of flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each the resulting realizations of the uncertain current field, we predict the optimal path by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  14. Improved electromagnetic tracking for catheter path reconstruction with application in high-dose-rate brachytherapy.

    Science.gov (United States)

    Lugez, Elodie; Sadjadi, Hossein; Joshi, Chandra P; Akl, Selim G; Fichtinger, Gabor

    2017-04-01

    Electromagnetic (EM) catheter tracking has recently been introduced in order to enable prompt and uncomplicated reconstruction of catheter paths in various clinical interventions. However, EM tracking is prone to measurement errors which can compromise the outcome of the procedure. Minimizing catheter tracking errors is therefore paramount to improve the path reconstruction accuracy. An extended Kalman filter (EKF) was employed to combine the nonlinear kinematic model of an EM sensor inside the catheter, with both its position and orientation measurements. The formulation of the kinematic model was based on the nonholonomic motion constraints of the EM sensor inside the catheter. Experimental verification was carried out in a clinical HDR suite. Ten catheters were inserted with mean curvatures varying from 0 to [Formula: see text] in a phantom. A miniaturized Ascension (Burlington, Vermont, USA) trakSTAR EM sensor (model 55) was threaded within each catheter at various speeds ranging from 7.4 to [Formula: see text]. The nonholonomic EKF was applied on the tracking data in order to statistically improve the EM tracking accuracy. A sample reconstruction error was defined at each point as the Euclidean distance between the estimated EM measurement and its corresponding ground truth. A path reconstruction accuracy was defined as the root mean square of the sample reconstruction errors, while the path reconstruction precision was defined as the standard deviation of these sample reconstruction errors. The impacts of sensor velocity and path curvature on the nonholonomic EKF method were determined. Finally, the nonholonomic EKF catheter path reconstructions were compared with the reconstructions provided by the manufacturer's filters under default settings, namely the AC wide notch and the DC adaptive filter. With a path reconstruction accuracy of 1.9 mm, the nonholonomic EKF surpassed the performance of the manufacturer's filters (2.4 mm) by 21% and the raw EM

  15. Paths from socioemotional behavior in middle childhood to personality in middle adulthood.

    Science.gov (United States)

    Pulkkinen, Lea; Kokko, Katja; Rantanen, Johanna

    2012-09-01

    Continuity in individual differences from socioemotional behavior in middle childhood to personality characteristics in middle adulthood was examined on the assumption that they share certain temperament-related elements. Socioemotional characteristics were measured using teacher ratings at ages 8 (N = 369; 53% males) and 14 (95% of the initial sample). Personality was assessed at age 42 (63% of the initial sample; 50% males) using a shortened version of the NEO Personality Inventory (NEO-PI); the Karolinska Scales of Personality (KSP); and the Adult Temperament Questionnaire (ATQ). Three models were tested using structural equation modeling. The results confirmed paths (a) from behavioral activity to adult Extraversion and Openness (NEO-PI), sociability (KSP), and surgency (ATQ); (b) from well-controlled behavior to adult conformity (KSP) and Conscientiousness (NEO-PI); and (c) from negative emotionality to adult aggression (KSP). The paths were significant only for one gender, and more frequently for males than for females. The significant male paths from behavioral activity to all indicators of adult activity and from well-controlled behavior to adult conformity started at age 8, whereas significant female paths from behavioral activity to adult sociability and from well-controlled behavior to adult Conscientiousness started at age 14. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  16. Gesture Recognition and Sensorimotor Learning-by-Doing of Motor Skills in Manual Professions: A Case Study in the Wheel-Throwing Art of Pottery

    Science.gov (United States)

    Glushkova, Alina; Manitsaris, Sotiris

    2018-01-01

    This paper presents a methodological framework for the use of gesture recognition technologies in the learning/mastery of the gestural skills required in wheel-throwing pottery. In the case of self-instruction or training, learners face difficulties due to the absence of the teacher/expert and the consequent lack of guidance. Motion capture…

  17. Specifically Prescribed Dynamic Thermodynamic Paths and Resolidification Experiments

    International Nuclear Information System (INIS)

    Nguyen, J; Orlikowski, D; Streitz, F; Holmes, N; Moriarty, J

    2003-11-01

    We describe here a series of dynamic compression experiments using impactors with specifically prescribed density profiles. Building upon previous impactor designs, we compose our functionally graded density impactors of materials whose densities vary from about 0.1 g/cc to more than 15 g/cc. These impactors, whose density profiles are not restricted to be monotonic, can be used to generate prescribed thermodynamic paths in the targets. These paths include quasi-isentropes as well as combinations of shock, rarefraction, and quasi-isentropic compression waves. The time-scale of these experiments ranges from nanoseconds to several microseconds. Strain-rates in the quasi-isentropic compression experiments vary from approximately 10 4 s -1 to 10 6 s -1 . We applied this quasi-isentropic compression technique to resolidify water where ice is at a higher temperature than the initial water sample. The particle velocity of quasi-isentropically compressed water exhibits a two-wave structure and sample thickness scales consistently with water-ice phase transition time. Experiments on resolidification of molten bismuth are also promising

  18. Can we throw information out of visual working memory and does this leave informational residue in long-term memory?

    OpenAIRE

    Ashleigh Monette Maxcey; Geoffrey F. Woodman

    2014-01-01

    Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this pr...

  19. Iterated Leavitt Path Algebras

    International Nuclear Information System (INIS)

    Hazrat, R.

    2009-11-01

    Leavitt path algebras associate to directed graphs a Z-graded algebra and in their simplest form recover the Leavitt algebras L(1,k). In this note, we introduce iterated Leavitt path algebras associated to directed weighted graphs which have natural ± Z grading and in their simplest form recover the Leavitt algebras L(n,k). We also characterize Leavitt path algebras which are strongly graded. (author)

  20. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  1. Using 10Be erosion rates and fluvial channel morphology to constrain fault throw rates in the southwestern Sacramento River Valley, California, USA

    Science.gov (United States)

    Cyr, A. J.

    2013-12-01

    activity on the west-vergent Sweitzer fault and the east-vergent blind reverse fault. All of the sampled catchments are underlain exclusively by Tehama Sandstone. Moreover, there are no mapped surface traces of faults in the sampled catchments. This minimizes the possibility of changes in lithogic resistance to impact the erosion rates and channel analyses. These analyses, combined with fault geometries derived from published seismic reflection data and structural cross sections, allows us to constrain the throw rates on these faults and thus better evaluate the associated seismic hazard.

  2. Aircraft path planning for optimal imaging using dynamic cost functions

    Science.gov (United States)

    Christie, Gordon; Chaudhry, Haseeb; Kochersberger, Kevin

    2015-05-01

    Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an "applications lag" for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggressively to exploit these capabilities has not been a primary focus in unmanned systems development. This paper addresses a means of aerial vehicle path planning to provide a realistic optimal path in acquiring imagery for structure from motion (SfM) reconstructions and performing radiation surveys. This method will allow SfM reconstructions to occur accurately and with minimal flight time so that the reconstructions can be executed efficiently. An assumption is made that we have 3D point cloud data available prior to the flight. A discrete set of scan lines are proposed for the given area that are scored based on visibility of the scene. Our approach finds a time-efficient path and calculates trajectories between scan lines and over obstacles encountered along those scan lines. Aircraft dynamics are incorporated into the path planning algorithm as dynamic cost functions to create optimal imaging paths in minimum time. Simulations of the path planning algorithm are shown for an urban environment. We also present our approach for image-based terrain mapping, which is able to efficiently perform a 3D reconstruction of a large area without the use of GPS data.

  3. Sensitivity of peak positions to flight-path parameters in a deep-inelastic scattering neutron TOF spectrometer

    International Nuclear Information System (INIS)

    Gray, E.MacA.; Chatzidimitriou-Dreismann, C.A.; Blach, T.P.

    2012-01-01

    The effects of small changes in flight-path parameters (primary and secondary flight paths, detector angles), and of displacement of the sample along the beam axis away from its ideal position, are examined for an inelastic time-of-flight (TOF) neutron spectrometer, emphasising the deep-inelastic regime. The aim was to develop a rational basis for deciding what measured shifts in the positions of spectral peaks could be regarded as reliable in the light of the uncertainties in the calibrated flight-path parameters. Uncertainty in the length of the primary or secondary flight path has the least effect on the positions of the peaks of H, D and He, which are dominated by the accuracy of the calibration of the detector angles. This aspect of the calibration of a TOF spectrometer therefore demands close attention to achieve reliable outcomes where the position of the peaks is of significant scientific interest and is discussed in detail. The corresponding sensitivities of the position of peak of the Compton profile, J(y), to flight-path parameters and sample position are also examined, focusing on the comparability across experiments of results for H, D and He. We show that positioning the sample to within a few mm of the ideal position is required to ensure good comparability between experiments if data from detectors at high forward angles are to be reliably interpreted.

  4. Note: A pure-sampling quantum Monte Carlo algorithm with independent Metropolis

    Energy Technology Data Exchange (ETDEWEB)

    Vrbik, Jan [Department of Mathematics, Brock University, St. Catharines, Ontario L2S 3A1 (Canada); Ospadov, Egor; Rothstein, Stuart M., E-mail: srothstein@brocku.ca [Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1 (Canada)

    2016-07-14

    Recently, Ospadov and Rothstein published a pure-sampling quantum Monte Carlo algorithm (PSQMC) that features an auxiliary Path Z that connects the midpoints of the current and proposed Paths X and Y, respectively. When sufficiently long, Path Z provides statistical independence of Paths X and Y. Under those conditions, the Metropolis decision used in PSQMC is done without any approximation, i.e., not requiring microscopic reversibility and without having to introduce any G(x → x′; τ) factors into its decision function. This is a unique feature that contrasts with all competing reptation algorithms in the literature. An example illustrates that dependence of Paths X and Y has adverse consequences for pure sampling.

  5. Note: A pure-sampling quantum Monte Carlo algorithm with independent Metropolis

    International Nuclear Information System (INIS)

    Vrbik, Jan; Ospadov, Egor; Rothstein, Stuart M.

    2016-01-01

    Recently, Ospadov and Rothstein published a pure-sampling quantum Monte Carlo algorithm (PSQMC) that features an auxiliary Path Z that connects the midpoints of the current and proposed Paths X and Y, respectively. When sufficiently long, Path Z provides statistical independence of Paths X and Y. Under those conditions, the Metropolis decision used in PSQMC is done without any approximation, i.e., not requiring microscopic reversibility and without having to introduce any G(x → x′; τ) factors into its decision function. This is a unique feature that contrasts with all competing reptation algorithms in the literature. An example illustrates that dependence of Paths X and Y has adverse consequences for pure sampling.

  6. Intercomparison of open-path trace gas measurements with two dual-frequency-comb spectrometers

    Directory of Open Access Journals (Sweden)

    E. M. Waxman

    2017-09-01

    Full Text Available We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm−1 (1568 to 1660 nm, corresponding to a 355 cm−1 bandwidth, at 0.0067 cm−1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10−4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO2, methane (CH4, water (H2O, and deuterated water (HDO. The retrieved dry mole fractions agree to 0.14 % (0.57 ppm for CO2, 0.35 % (7 ppb for CH4, and 0.40 % (36 ppm for H2O at  ∼  30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO2 and CH4 that are consistent with the presence of local sources of CO2 and absence of local sources of CH4.

  7. Mechanistic Insights on Human Phosphoglucomutase Revealed by Transition Path Sampling and Molecular Dynamics Calculations.

    Science.gov (United States)

    Brás, Natércia F; Fernandes, Pedro A; Ramos, Maria J; Schwartz, Steven D

    2018-02-06

    Human α-phosphoglucomutase 1 (α-PGM) catalyzes the isomerization of glucose-1-phosphate into glucose-6-phosphate (G6P) through two sequential phosphoryl transfer steps with a glucose-1,6-bisphosphate (G16P) intermediate. Given that the release of G6P in the gluconeogenesis raises the glucose output levels, α-PGM represents a tempting pharmacological target for type 2 diabetes. Here, we provide the first theoretical study of the catalytic mechanism of human α-PGM. We performed transition-path sampling simulations to unveil the atomic details of the two catalytic chemical steps, which could be key for developing transition state (TS) analogue molecules with inhibitory properties. Our calculations revealed that both steps proceed through a concerted S N 2-like mechanism, with a loose metaphosphate-like TS. Even though experimental data suggests that the two steps are identical, we observed noticeable differences: 1) the transition state ensemble has a well-defined TS region and a late TS for the second step, and 2) larger coordinated protein motions are required to reach the TS of the second step. We have identified key residues (Arg23, Ser117, His118, Lys389), and the Mg 2+ ion that contribute in different ways to the reaction coordinate. Accelerated molecular dynamics simulations suggest that the G16P intermediate may reorient without leaving the enzymatic binding pocket, through significant conformational rearrangements of the G16P and of specific loop regions of the human α-PGM. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

    Science.gov (United States)

    Pontaga, Inese; Zidens, Janis

    2014-01-01

    The aim of the investigation was to: 1) compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external– concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles. PMID:25414738

  9. Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

    Directory of Open Access Journals (Sweden)

    Pontaga Inese

    2014-10-01

    Full Text Available The aim of the investigation was to: 1 compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2 determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15- year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg. The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external- concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles

  10. The experimental electron mean-free-path in Si under typical (S)TEM conditions

    International Nuclear Information System (INIS)

    Potapov, P.L.

    2014-01-01

    The electron mean-free-path in Si was measured by EELS using the test structure with the certified dimensions as a calibration standard. In a good agreement with the previous CBED measurements, the mean-free-path is 150 nm for 200 keV and 179 nm for 300 keV energy of primary electrons at large collection angles. These values are accurately predicted by the model of Iakoubovskii et al. while the model of Malis et al. incorporated in common microscopy software underestimates the mean-free-path by 15% at least. Correspondingly, the thickness of TEM samples reported in many studies of the Si-based materials last decades might be noticeably underestimated. - Highlights: • The electron inelastic mean-free-path in Si is measured for the typical (S)TEM conditions. • These reference values allow for accurate determination of the lamella thickness by EELS. • The theoretical model by Malis et al. underestimates the mean-free-path values

  11. Shortest Paths and Vehicle Routing

    DEFF Research Database (Denmark)

    Petersen, Bjørn

    This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...... Routing Problem based on partial paths is presented. Finally, a practical application of finding shortest paths in the telecommunication industry is shown....

  12. [Dual insertion paths design characteristics and short-term clinical observation of rotational path removable partial dentures].

    Science.gov (United States)

    Li, Jian; Jiang, Ting; Li, Sai; Chen, Wei

    2013-02-18

    To investigate design methods of dual insertion paths and observe a short-term clinic overview of rotational path removable partial dentures (RPDs). In the study, 40 patients with partial edentulous arches were included and divided into two groups. The patients in group one were restored with rotational path RPDs (10 Kennedy class III and 10 Kennedy class IV respectively). The patients in group two (20 patients), whose edentulous area was matched with the patients' in group one, were restored with the linear path RPDs. After surveying and simulative preparation on diagnostic casts, the basic laws of designing rotational path RPDs were summarized. The oral preparation was accurately performed under the guidance of indices made on diagnostic casts after simulative preparation. The 40 dentures were recalled two weeks and one year after the insertion. The evaluations of the clinic outcome, including retention, stability, mastication function, esthetics and wearing convenience, were marked out as good, acceptable, and poor. The comparison of the evaluation results was performed between the two groups. In the rotational path design for Kennedy class III or IV RPDs, the angles (α) of dual insertion paths should be designed within a scope, approximate 10°-15°.When the angle (α) became larger, the denture retention turned to be better, but accordingly the posterior abutments needed more preparation. In the clinical application, the first insertions of the 40 dentures were all favorably accomplished. When the rotational path RPDs were compared to linear path RPDs, the time consuming on first insertion had no statistical difference[(32±8) min and (33±8) min respectively, P>0.05]. Recalled two weeks and one year after the insertion, in the esthetics evaluation, 20 rotational path RPDs were all evaluated as "A", but only 7(two weeks after) and 6 (one year after) linear path RPDs were evaluated as "A"(P<0.05). There was no significant difference in other evaluation results

  13. Path planning in changeable environments

    NARCIS (Netherlands)

    Nieuwenhuisen, D.

    2007-01-01

    This thesis addresses path planning in changeable environments. In contrast to traditional path planning that deals with static environments, in changeable environments objects are allowed to change their configurations over time. In many cases, path planning algorithms must facilitate quick

  14. Comparison of classical reaction paths and tunneling paths studied with the semiclassical instanton theory.

    Science.gov (United States)

    Meisner, Jan; Markmeyer, Max N; Bohner, Matthias U; Kästner, Johannes

    2017-08-30

    Atom tunneling in the hydrogen atom transfer reaction of the 2,4,6-tri-tert-butylphenyl radical to 3,5-di-tert-butylneophyl, which has a short but strongly curved reaction path, was investigated using instanton theory. We found the tunneling path to deviate qualitatively from the classical intrinsic reaction coordinate, the steepest-descent path in mass-weighted Cartesian coordinates. To perform that comparison, we implemented a new variant of the predictor-corrector algorithm for the calculation of the intrinsic reaction coordinate. We used the reaction force analysis method as a means to decompose the reaction barrier into structural and electronic components. Due to the narrow energy barrier, atom tunneling is important in the abovementioned reaction, even above room temperature. Our calculated rate constants between 350 K and 100 K agree well with experimental values. We found a H/D kinetic isotope effect of almost 10 6 at 100 K. Tunneling dominates the protium transfer below 400 K and the deuterium transfer below 300 K. We compared the lengths of the tunneling path and the classical path for the hydrogen atom transfer in the reaction HCl + Cl and quantified the corner cutting in this reaction. At low temperature, the tunneling path is about 40% shorter than the classical path.

  15. High Isolation Single-Pole Four-Throw RF MEMS Switch Based on Series-Shunt Configuration

    Directory of Open Access Journals (Sweden)

    Tejinder Singh

    2014-01-01

    Full Text Available This paper presents a novel design of single-pole four-throw (SP4T RF-MEMS switch employing both capacitive and ohmic switches. It is designed on high-resistivity silicon substrate and has a compact area of 1.06 mm2. The series or ohmic switches have been designed to provide low insertion loss with good ohmic contact. The pull-in voltage for ohmic switches is calculated to be 7.19 V. Shunt or capacitive switches have been used in each port to improve the isolation for higher frequencies. The proposed SP4T switch provides excellent RF performances with isolation better than 70.64 dB and insertion loss less than 0.72 dB for X-band between the input port and each output port.

  16. DiversePathsJ: diverse shortest paths for bioimage analysis.

    Science.gov (United States)

    Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

    2018-02-01

    We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  17. de Broglie Swapping Metadynamics for Quantum and Classical Sampling.

    Science.gov (United States)

    Nava, Marco; Quhe, Ruge; Palazzesi, Ferruccio; Tiwary, Pratyush; Parrinello, Michele

    2015-11-10

    This paper builds on our previous work on Path Integral Metadynamics [ Ruge et al. J. Chem. Theory Comput. 2015 , 11 , 1383 ] in which we have accelerated sampling in quantum systems described by Feynman's Path Integrals using Metadynamics. We extend the scope of Path Integral Metadynamics by combining it with a replica exchange scheme in which artificially enhanced quantum effects play the same role as temperature does in parallel tempering. Our scheme can be adapted so as to be used in an ancillary way to sample systems described by classical statistical mechanics. Contrary to Metadynamics and many other sampling methods no collective variables need to be defined. The method in its two variants, quantum and classical, is tested in a number of examples.

  18. Path integrals on curved manifolds

    International Nuclear Information System (INIS)

    Grosche, C.; Steiner, F.

    1987-01-01

    A general framework for treating path integrals on curved manifolds is presented. We also show how to perform general coordinate and space-time transformations in path integrals. The main result is that one has to subtract a quantum correction ΔV ∝ ℎ 2 from the classical Lagrangian L, i.e. the correct effective Lagrangian to be used in the path integral is L eff = L-ΔV. A general prescription for calculating the quantum correction ΔV is given. It is based on a canonical approach using Weyl-ordering and the Hamiltonian path integral defined by the midpoint prescription. The general framework is illustrated by several examples: The d-dimensional rotator, i.e. the motion on the sphere S d-1 , the path integral in d-dimensional polar coordinates, the exact treatment of the hydrogen atom in R 2 and R 3 by performing a Kustaanheimo-Stiefel transformation, the Langer transformation and the path integral for the Morse potential. (orig.)

  19. Welding Robot Collision-Free Path Optimization

    Directory of Open Access Journals (Sweden)

    Xuewu Wang

    2017-02-01

    Full Text Available Reasonable welding path has a significant impact on welding efficiency, and a collision-free path should be considered first in the process of welding robot path planning. The shortest path length is considered as an optimization objective, and obstacle avoidance is considered as the constraint condition in this paper. First, a grid method is used as a modeling method after the optimization objective is analyzed. For local collision-free path planning, an ant colony algorithm is selected as the search strategy. Then, to overcome the shortcomings of the ant colony algorithm, a secondary optimization is presented to improve the optimization performance. Finally, the particle swarm optimization algorithm is used to realize global path planning. Simulation results show that the desired welding path can be obtained based on the optimization strategy.

  20. Hamiltonian path integrals

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1982-01-01

    The properties of path integrals associated with the allowance for nonstandard terms reflecting the operator nature of the canonical variables are considered. Rules for treating such terms (''equivalence rules'') are formulated. Problems with a boundary, the behavior of path integrals under canonical transformations, and the problem of quantization of dynamical systems with constraints are considered in the framework of the method

  1. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong; Le Maitre, Olivier; Hoteit, Ibrahim; Knio, Omar

    2016-01-01

    the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning

  2. Symbolic PathFinder v7

    DEFF Research Database (Denmark)

    Luckow, Kasper Søe; Păsăreanu, Corina

    2014-01-01

    We describe Symbolic PathFinder v7 in terms of its updated design addressing the changes of Java PathFinder v7 and of its new optimization when computing path conditions. Furthermore, we describe the Symbolic Execution Tree Extension; a newly added feature that allows for outputting the symbolic...... execution tree that characterizes the execution paths covered during symbolic execution. The new extension can be tailored to the needs of subsequent analyses/processing facilities, and we demonstrate this by presenting SPF-Visualizer, which is a tool for customizable visualization of the symbolic execution...

  3. Evaluating Status Change of Soil Potassium from Path Model

    Science.gov (United States)

    He, Wenming; Chen, Fang

    2013-01-01

    The purpose of this study is to determine critical environmental parameters of soil K availability and to quantify those contributors by using a proposed path model. In this study, plot experiments were designed into different treatments, and soil samples were collected and further analyzed in laboratory to investigate soil properties influence on soil potassium forms (water soluble K, exchangeable K, non-exchangeable K). Furthermore, path analysis based on proposed path model was carried out to evaluate the relationship between potassium forms and soil properties. Research findings were achieved as followings. Firstly, key direct factors were soil S, ratio of sodium-potassium (Na/K), the chemical index of alteration (CIA), Soil Organic Matter in soil solution (SOM), Na and total nitrogen in soil solution (TN), and key indirect factors were Carbonate (CO3), Mg, pH, Na, S, and SOM. Secondly, path model can effectively determine direction and quantities of potassium status changes between Exchangeable potassium (eK), Non-exchangeable potassium (neK) and water-soluble potassium (wsK) under influences of specific environmental parameters. In reversible equilibrium state of , K balance state was inclined to be moved into β and χ directions in treatments of potassium shortage. However in reversible equilibrium of , K balance state was inclined to be moved into θ and λ directions in treatments of water shortage. Results showed that the proposed path model was able to quantitatively disclose moving direction of K status and quantify its equilibrium threshold. It provided a theoretical and practical basis for scientific and effective fertilization in agricultural plants growth. PMID:24204659

  4. MEASURING PATH DEPENDENCY

    Directory of Open Access Journals (Sweden)

    Peter Juhasz

    2017-03-01

    Full Text Available While risk management gained popularity during the last decades even some of the basic risk types are still far out of focus. One of these is path dependency that refers to the uncertainty of how we reach a certain level of total performance over time. While decision makers are careful in accessing how their position will look like the end of certain periods, little attention is given how they will get there through the period. The uncertainty of how a process will develop across a shorter period of time is often “eliminated” by simply choosing a longer planning time interval, what makes path dependency is one of the most often overlooked business risk types. After reviewing the origin of the problem we propose and compare seven risk measures to access path. Traditional risk measures like standard deviation of sub period cash flows fail to capture this risk type. We conclude that in most cases considering the distribution of the expected cash flow effect caused by the path dependency may offer the best method, but we may need to use several measures at the same time to include all the optimisation limits of the given firm

  5. The Effects of Shoulder- Girdle Muscles Fatigue on Ground Reaction Force, Elbow and Shoulder Joint Angle, and Accuracy of the Athletic Performance in Handball Penalty Throws

    Directory of Open Access Journals (Sweden)

    Mona Shiravand

    2017-09-01

    Discussion: As the subjects were professional, muscle fatigue did not have a significant effect on postural control, angles and angular velocity; but did affect the reaction force and accuracy of the throws before and after fatigue, which could ultimately affect the performance of athletes and competition results.

  6. Path integration in conical space

    International Nuclear Information System (INIS)

    Inomata, Akira; Junker, Georg

    2012-01-01

    Quantum mechanics in conical space is studied by the path integral method. It is shown that the curvature effect gives rise to an effective potential in the radial path integral. It is further shown that the radial path integral in conical space can be reduced to a form identical with that in flat space when the discrete angular momentum of each partial wave is replaced by a specific non-integral angular momentum. The effective potential is found proportional to the squared mean curvature of the conical surface embedded in Euclidean space. The path integral calculation is compatible with the Schrödinger equation modified with the Gaussian and the mean curvature. -- Highlights: ► We study quantum mechanics on a cone by the path integral approach. ► The path integral depends only on the metric and the curvature effect is built in. ► The approach is consistent with the Schrödinger equation modified by an effective potential. ► The effective potential is found to be of the “Jensen–Koppe” and “da Costa” type.

  7. Two dimensional simplicial paths

    International Nuclear Information System (INIS)

    Piso, M.I.

    1994-07-01

    Paths on the R 3 real Euclidean manifold are defined as 2-dimensional simplicial strips which are orbits of the action of a discrete one-parameter group. It is proven that there exists at least one embedding of R 3 in the free Z-module generated by S 2 (x 0 ). The speed is defined as the simplicial derivative of the path. If mass is attached to the simplex, the free Lagrangian is proportional to the width of the path. In the continuum limit, the relativistic form of the Lagrangian is recovered. (author). 7 refs

  8. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  9. Cooperative organic mine avoidance path planning

    Science.gov (United States)

    McCubbin, Christopher B.; Piatko, Christine D.; Peterson, Adam V.; Donnald, Creighton R.; Cohen, David

    2005-06-01

    The JHU/APL Path Planning team has developed path planning techniques to look for paths that balance the utility and risk associated with different routes through a minefield. Extending on previous years' efforts, we investigated real-world Naval mine avoidance requirements and developed a tactical decision aid (TDA) that satisfies those requirements. APL has developed new mine path planning techniques using graph based and genetic algorithms which quickly produce near-minimum risk paths for complicated fitness functions incorporating risk, path length, ship kinematics, and naval doctrine. The TDA user interface, a Java Swing application that obtains data via Corba interfaces to path planning databases, allows the operator to explore a fusion of historic and in situ mine field data, control the path planner, and display the planning results. To provide a context for the minefield data, the user interface also renders data from the Digital Nautical Chart database, a database created by the National Geospatial-Intelligence Agency containing charts of the world's ports and coastal regions. This TDA has been developed in conjunction with the COMID (Cooperative Organic Mine Defense) system. This paper presents a description of the algorithms, architecture, and application produced.

  10. The burden of secrecy? No effect on hill slant estimation and beanbag throwing.

    Science.gov (United States)

    Pecher, Diane; van Mierlo, Heleen; Cañal-Bruland, Rouwen; Zeelenberg, René

    2015-08-01

    Slepian, Masicampo, Toosi, and Ambady (2012, Experiment 1) reported that participants who recalled a big secret estimated a hill as steeper than participants who recalled a small secret. This finding was interpreted as evidence that secrets are experienced as physical burdens. In 2 experiments, we tried to replicate this finding, but, despite larger power, did not find a difference in slant estimates between participants who recalled a big secret and those who recalled a small secret. This finding was further corroborated by a meta-analysis that included 8 published data sets of exact replications, which indicates that thinking of a big secret does not affect hill slant estimation. In a third experiment, we also failed to replicate the effect of recalling a secret on throwing a beanbag at a target (Slepian et al., 2012, Experiment 2). Together, our findings question the robustness of the original empirical findings. (c) 2015 APA, all rights reserved).

  11. The effect of solar and lunar currents on simultaneous phase path, group path and amplitude measurements

    International Nuclear Information System (INIS)

    Baulch, R.N.E.; Butcher, E.C.

    1984-01-01

    The solar and lunar variations in the phase path, group path and amplitude of a fixed frequency transmission were obtained at the September equinox over a slightly oblique path. The phase of the lunar semi-diurnal tide in the phase path and amplitude were similar, the maxima occurring near 0200 lunar time, whereas the group path had a maximum near 0800 lunar time. These results were compared with other results obtained near the same location. The results suggest a complex situation in the E-region, where the height of the lunar current depends on season, and also suggest that the location and distribution of the solar and lunar currents may be different. (author)

  12. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  13. NEW UPPER AND LOWER BOUNDS LINE OF SIGHT PATH LOSS MODELS FOR MOBILE PROPAGATION IN BUILDINGS

    Directory of Open Access Journals (Sweden)

    Supachai Phaiboon

    2017-11-01

    Full Text Available This paper proposes a method to predict line-of-sight (LOS path loss in buildings. We performed measurements in two different type of buildings at a frequency of 1.8 GHz and propose new upper and lower bounds path loss models which depend on max and min values of sample path loss data. This makes our models limit path loss within the boundary lines. The models include time-variant effects such as people moving and cars in parking areas with their influence on wave propagation that is very high.  The results have shown that the proposed models will be useful for the system and cell design of indoor wireless communication systems.

  14. On the structure of path-like trees

    OpenAIRE

    Muntaner Batle, Francesc Antoni; Rius Font, Miquel

    2007-01-01

    We study the structure of path-like trees. In order to do this, we introduce a set of trees that we call expandable trees. In this paper we also generalize the concept of path-like trees and we call such generalization generalized path-like trees. As in the case of path-like trees, generalized path-like trees, have very nice labeling properties.

  15. Evaluating status change of soil potassium from path model.

    Directory of Open Access Journals (Sweden)

    Wenming He

    Full Text Available The purpose of this study is to determine critical environmental parameters of soil K availability and to quantify those contributors by using a proposed path model. In this study, plot experiments were designed into different treatments, and soil samples were collected and further analyzed in laboratory to investigate soil properties influence on soil potassium forms (water soluble K, exchangeable K, non-exchangeable K. Furthermore, path analysis based on proposed path model was carried out to evaluate the relationship between potassium forms and soil properties. Research findings were achieved as followings. Firstly, key direct factors were soil S, ratio of sodium-potassium (Na/K, the chemical index of alteration (CIA, Soil Organic Matter in soil solution (SOM, Na and total nitrogen in soil solution (TN, and key indirect factors were Carbonate (CO3, Mg, pH, Na, S, and SOM. Secondly, path model can effectively determine direction and quantities of potassium status changes between Exchangeable potassium (eK, Non-exchangeable potassium (neK and water-soluble potassium (wsK under influences of specific environmental parameters. In reversible equilibrium state of [Formula: see text], K balance state was inclined to be moved into β and χ directions in treatments of potassium shortage. However in reversible equilibrium of [Formula: see text], K balance state was inclined to be moved into θ and λ directions in treatments of water shortage. Results showed that the proposed path model was able to quantitatively disclose moving direction of K status and quantify its equilibrium threshold. It provided a theoretical and practical basis for scientific and effective fertilization in agricultural plants growth.

  16. The influence of parenting style on academic achievement and career path.

    Science.gov (United States)

    Zahed Zahedani, Zahra; Rezaee, Rita; Yazdani, Zahra; Bagheri, Sina; Nabeiei, Parisa

    2016-07-01

    Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences. This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind's Parenting Style and Moqimi's Career Path questionnaires were used and the obtained scores were correlated with the students' transcripts. To study the relation between variables Pearson correlation coefficient was used. There was a significant relationship between authoritarian parenting style and educational success (p=0.03). Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001). Parents have an important role in identifying children's talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes.

  17. Simulation and validation of concentrated subsurface lateral flow paths in an agricultural landscape

    Science.gov (United States)

    Zhu, Q.; Lin, H. S.

    2009-08-01

    and thus is a useful indicator of possible subsurface flow path over a large area; and (3) observable Mn distribution in soil profiles can be used as a simple indicator of water flow paths in soils and over the landscape; however, it does require sufficient soil sampling (by excavation or augering) to possibly infer landscape-scale subsurface flow paths. In areas where subsurface interface topography varies similarly with surface topography, surface DEM can be used to simulate potential subsurface lateral flow path reasonably so the cost associated with obtaining depth to subsurface water-restricting layer can be minimized.

  18. Controlling the optical path length in turbid media using differential path-length spectroscopy: fiber diameter dependence

    NARCIS (Netherlands)

    Kaspers, O. P.; Sterenborg, H. J. C. M.; Amelink, A.

    2008-01-01

    We have characterized the path length for the differential path-length spectroscopy (DPS) fiber optic geometry for a wide range of optical properties and for fiber diameters ranging from 200 mu m to 1000 mu m. Phantom measurements show that the path length is nearly constant for scattering

  19. A Method on Dynamic Path Planning for Robotic Manipulator Autonomous Obstacle Avoidance Based on an Improved RRT Algorithm.

    Science.gov (United States)

    Wei, Kun; Ren, Bingyin

    2018-02-13

    In a future intelligent factory, a robotic manipulator must work efficiently and safely in a Human-Robot collaborative and dynamic unstructured environment. Autonomous path planning is the most important issue which must be resolved first in the process of improving robotic manipulator intelligence. Among the path-planning methods, the Rapidly Exploring Random Tree (RRT) algorithm based on random sampling has been widely applied in dynamic path planning for a high-dimensional robotic manipulator, especially in a complex environment because of its probability completeness, perfect expansion, and fast exploring speed over other planning methods. However, the existing RRT algorithm has a limitation in path planning for a robotic manipulator in a dynamic unstructured environment. Therefore, an autonomous obstacle avoidance dynamic path-planning method for a robotic manipulator based on an improved RRT algorithm, called Smoothly RRT (S-RRT), is proposed. This method that targets a directional node extends and can increase the sampling speed and efficiency of RRT dramatically. A path optimization strategy based on the maximum curvature constraint is presented to generate a smooth and curved continuous executable path for a robotic manipulator. Finally, the correctness, effectiveness, and practicability of the proposed method are demonstrated and validated via a MATLAB static simulation and a Robot Operating System (ROS) dynamic simulation environment as well as a real autonomous obstacle avoidance experiment in a dynamic unstructured environment for a robotic manipulator. The proposed method not only provides great practical engineering significance for a robotic manipulator's obstacle avoidance in an intelligent factory, but also theoretical reference value for other type of robots' path planning.

  20. Two ways related to performance in elite sport: the path of self-confidence and competitive anxiety and the path of group cohesion and group goal-clarity.

    Science.gov (United States)

    Kjørmo, Odd; Halvari, Hallgeir

    2002-06-01

    A model tested among 136 Norwegian Olympic-level athletes yielded two paths related to performance. The first path indicated that self-confidence, modeled as an antecedent of competitive anxiety, is negatively correlated with anxiety. Competitive anxiety in turn is negatively correlated with performance. The second path indicated that group cohesion is positively correlated with group goal-clarity, which in turn is positively correlated with performance. Competitive anxiety mediates the relation between self-confidence and performance, whereas group goal-clarity mediates the relation between group cohesion and performance. Results from multiple regression analyses supported the model in the total sample and among individual sport athletes organized in training groups (n = 100). Among team sport athletes (n = 36), personality and group measures are more strongly intercorrelated than among individual sport athletes, and the relation with performance is more complex for the former group. The interaction of self-confidence and competitive anxiety is related to performance among team sport athletes.

  1. Additional collection devices used in conjunction with the SurePath Liquid-Based Pap Test broom device do not enhance diagnostic utility

    Directory of Open Access Journals (Sweden)

    O'Connor Jason C

    2004-09-01

    Full Text Available Abstract Background We have previously shown that use of an EC brush device in combination with the Rovers Cervex-Brush (SurePath broom offered no significant improvement in EC recovery. Here we determine if use of additional collection devices enhance the diagnostic utility of the SurePath Pap for gynecologic cytology. Methods After informed consent, 37 women ages 18–56 receiving their routine cervical examinations were randomized into four experimental groups. Each group was first sampled with the SurePath broom then immediately re-sampled with an additional collection device or devices. Group 1: Rover endocervix brush (n = 8. Group 2: Medscand CytoBrush Plus GT (n = 7. Group 3: Rover spatula + endocervix brush (n = 11. Group 4: Medscand spatula + CytoBrush Plus GT (n = 11. Results Examination of SurePath broom-collected cytology yielded the following abnormal diagnoses: atypia (n = 2, LSIL (n = 5 and HSIL (n = 3. Comparison of these diagnoses to those obtained from paired samples using the additional collection devices showed that use of a second and or third device yielded no additional abnormal diagnoses. Importantly, use of additional devices did not improve upon the abnormal cell recovery of the SurePath broom and in 4/10 cases under-predicted or did not detect the SurePath broom-collected lesion as confirmed by cervical biopsy. Finally, in 36/37 cases, the SurePath broom successfully recovered ECs. Use of additional devices, in Group 3, augmented EC recovery to 37/37. Conclusions Use of additional collection devices in conjunction with the SurePath broom did not enhance diagnostic utility of the SurePath Pap. A potential but not significant improvement in EC recovery might be seen with the use of three devices.

  2. A path integral methodology for obtaining thermodynamic properties of nonadiabatic systems using Gaussian mixture distributions

    Science.gov (United States)

    Raymond, Neil; Iouchtchenko, Dmitri; Roy, Pierre-Nicholas; Nooijen, Marcel

    2018-05-01

    We introduce a new path integral Monte Carlo method for investigating nonadiabatic systems in thermal equilibrium and demonstrate an approach to reducing stochastic error. We derive a general path integral expression for the partition function in a product basis of continuous nuclear and discrete electronic degrees of freedom without the use of any mapping schemes. We separate our Hamiltonian into a harmonic portion and a coupling portion; the partition function can then be calculated as the product of a Monte Carlo estimator (of the coupling contribution to the partition function) and a normalization factor (that is evaluated analytically). A Gaussian mixture model is used to evaluate the Monte Carlo estimator in a computationally efficient manner. Using two model systems, we demonstrate our approach to reduce the stochastic error associated with the Monte Carlo estimator. We show that the selection of the harmonic oscillators comprising the sampling distribution directly affects the efficiency of the method. Our results demonstrate that our path integral Monte Carlo method's deviation from exact Trotter calculations is dominated by the choice of the sampling distribution. By improving the sampling distribution, we can drastically reduce the stochastic error leading to lower computational cost.

  3. Walking path-planning method for multiple radiation areas

    International Nuclear Information System (INIS)

    Liu, Yong-kuo; Li, Meng-kun; Peng, Min-jun; Xie, Chun-li; Yuan, Cheng-qian; Wang, Shuang-yu; Chao, Nan

    2016-01-01

    Highlights: • Radiation environment modeling method is designed. • Path-evaluating method and segmented path-planning method are proposed. • Path-planning simulation platform for radiation environment is built. • The method avoids to be misled by minimum dose path in single area. - Abstract: Based on minimum dose path-searching method, walking path-planning method for multiple radiation areas was designed to solve minimum dose path problem in single area and find minimum dose path in the whole space in this paper. Path-planning simulation platform was built using C# programming language and DirectX engine. The simulation platform was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method is effective in providing safety for people walking in nuclear facilities.

  4. On the structure and surface chemical composition of indium-tin oxide films prepared by long-throw magnetron sputtering

    International Nuclear Information System (INIS)

    Chuang, M.J.; Huang, H.F.; Wen, C.H.; Chu, A.K.

    2010-01-01

    Structures and surface chemical composition of indium tin oxide (ITO) thin films prepared by long-throw radio-frequency magnetron sputtering technique have been investigated. The ITO films were deposited on glass substrates using a 20 cm target-to-substrate distance in a pure argon sputtering environment. X-ray diffraction results showed that an increase in substrate temperature resulted in ITO structure evolution from amorphous to polycrystalline. Field-emission scanning electron microscopy micrographs suggested that the ITO films were free of bombardment of energetic particles since the microstructures of the films exhibited a smaller grain size and no sub-grain boundary could be observed. The surface composition of the ITO films was characterized by X-ray photoelectron spectroscopy (XPS). Oxygen atoms in both amorphous and crystalline ITO structures were observed from O 1 s XPS spectra. However, the peak of the oxygen atoms in amorphous ITO phase could only be found in samples prepared at low substrate temperatures. Its relative peak area decreased drastically when substrate temperatures were larger than 200 o C. In addition, a composition analysis from the XPS results revealed that the films deposited at low substrate temperatures contained high concentration of oxygen at the film surfaces. The oxygen-rich surfaces can be attributed to hydrolysis reactions of indium oxides, especially when large amount of the amorphous ITO were developed near the film surfaces.

  5. Calculation of force and power during bench throws using a Smith machine: the importance of considering the effect of counterweights.

    Science.gov (United States)

    Kobayashi, Y; Narazaki, K; Akagi, R; Nakagaki, K; Kawamori, N; Ohta, K

    2013-09-01

    For achieving accurate and safe measurements of the force and power exerted on a load during resistance exercise, the Smith machine has been used instead of free weights. However, because some Smith machines possess counterweights, the equation for the calculation of force and power in this system should be different from the one used for free weights. The purpose of this investigation was to calculate force and power using an equation derived from a dynamic equation for a Smith machine with counterweights and to determine the differences in force and power calculated using 2 different equations. One equation was established ignoring the effect of the counterweights (Method 1). The other equation was derived from a dynamic equation for a barbell and counterweight system (Method 2). 9 female collegiate judo athletes performed bench throws using a Smith machine with a counterweight at 6 different loading conditions. Barbell displacement was recorded using a linear position transducer. The force and power were subsequently calculated by Methods 1 and 2. The results showed that the mean and peak power and force in Method 1 were significantly lower relative to those of Method 2 under all loading conditions. These results indicate that the mean and peak power and force during bench throwing using a Smith machine with counterweights would be underestimated when the calculations used to determine these parameters do not account for the effect of counterweights. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Cooperative path planning of unmanned aerial vehicles

    CERN Document Server

    Tsourdos, Antonios; Shanmugavel, Madhavan

    2010-01-01

    An invaluable addition to the literature on UAV guidance and cooperative control, Cooperative Path Planning of Unmanned Aerial Vehicles is a dedicated, practical guide to computational path planning for UAVs. One of the key issues facing future development of UAVs is path planning: it is vital that swarm UAVs/ MAVs can cooperate together in a coordinated manner, obeying a pre-planned course but able to react to their environment by communicating and cooperating. An optimized path is necessary in order to ensure a UAV completes its mission efficiently, safely, and successfully. Focussing on the path planning of multiple UAVs for simultaneous arrival on target, Cooperative Path Planning of Unmanned Aerial Vehicles also offers coverage of path planners that are applicable to land, sea, or space-borne vehicles. Cooperative Path Planning of Unmanned Aerial Vehicles is authored by leading researchers from Cranfield University and provides an authoritative resource for researchers, academics and engineers working in...

  7. An analysis of the relationship between the linear hammer speed and the thrower applied forces during the hammer throw for male and female throwers.

    Science.gov (United States)

    Brice, Sara M; Ness, Kevin F; Rosemond, Doug

    2011-09-01

    The purpose of this study was to investigate the relationship between the cable force and linear hammer speed in the hammer throw and to identify how the magnitude and direction of the cable force affects the fluctuations in linear hammer speed. Five male (height: 1.88 +/- 0.06 m; body mass: 106.23 +/- 4.83 kg) and five female (height: 1.69 +/- 0.05 m; body mass: 101.60 +/- 20.92 kg) throwers participated and were required to perform 10 throws each. The hammer's linear velocity and the cable force and its tangential component were calculated via hammer head positional data. As expected, a strong correlation was observed between decreases in the linear hammer speed and decreases in the cable force (normalised for hammer weight). A strong correlation was also found to exist between the angle by which the cable force lags the radius of rotation at its maximum (when tangential force is at its most negative) and the size of the decreases in hammer speed. These findings indicate that the most effective way to minimise the effect of the negative tangential force is to reduce the size of the lag angle.

  8. Strain path dependency in metal plasticity

    NARCIS (Netherlands)

    Viatkina, E.M.; Brekelmans, W.A.M.; Geers, M.G.D.

    2003-01-01

    A change in strain path has a significant effect on the mechanical response of metals. Strain path change effects physically originate from a complex microstructure evolution. This paper deals with the contribution of cell structure evolution to the strain path change effect. The material with cells

  9. PENGARUH MODEL PEMBELAJARAN KOOPERATIF TIPE SNOWBALL THROWING TERHADAP HASIL BELAJAR SISWA PADA KONSEP SALING KETERGANTUNGAN DALAM EKOSISTEM DI KELAS VII SMP NEGERI 18 PEKANBARU TAHUN AJARAN 2014 / 2015

    Directory of Open Access Journals (Sweden)

    Jumiati Jumiati

    2017-07-01

    Full Text Available The aim of this research was to find out the effect of cooperative learning type snowballthrowing to improve student learning achievement on the reliance mutualin in theecosystem concept. The research was conducted at SMP Negeri 18 Pekanbaru at firstsemester in academic years 2014 / 2015. Design of the research was quasi-experimental,The Matching Only Pretest – Posttest Control Group Design. Sample of the research wastaken two classes with the number of students in each 40 people who were taken by usingsimple random sampling technique. The data were collected by using pretest, posttest andteacher’s and students’ activities observation sheets. The data analysis technique used inthis research was 2 sample independent t test, if the data were normal and homogen. Themean N-gain experimental class was 0.72 high category and the control class was 0.44medium category. Based on the result of statistical test that there were significantdifferences between the mean N-Gain experimental class and control class. Thereby canbe conluded that there were significant application of cooperative learning type snowballthrowing to improve student learning achievement on the reliance mutualin in theecosystem concept class VII SMPN 18 pekanbaru academic year 2014 / 2015.Key words : snowball throwing, learning achievement, ecosystem.

  10. Path-Goal Theory of Leadership

    Science.gov (United States)

    1975-04-01

    Leadership and Turnover Among Managers ," Organization Behavior and Human Performance, 10(1973), pp. 184-200; R. J. House, "A Path-Goal Theory of...of Leadership ." 6R. J. House and G. Dessler, "Path-Goal Theory of Leadership " R. M. Stqg- dill. Managers , Employees, Organization (Ohio State...of Control." 23 R. J. House, "Notes on the Path-Goal Theory of Leadership " (University of Toronto, Faculty of Management Studies, May 1974). 24 R

  11. Path integral in Snyder space

    Energy Technology Data Exchange (ETDEWEB)

    Mignemi, S., E-mail: smignemi@unica.it [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy); Štrajn, R. [Dipartimento di Matematica e Informatica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria, 09042 Monserrato (Italy)

    2016-04-29

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  12. Path integral in Snyder space

    International Nuclear Information System (INIS)

    Mignemi, S.; Štrajn, R.

    2016-01-01

    The definition of path integrals in one- and two-dimensional Snyder space is discussed in detail both in the traditional setting and in the first-order formalism of Faddeev and Jackiw. - Highlights: • The definition of the path integral in Snyder space is discussed using phase space methods. • The same result is obtained in the first-order formalism of Faddeev and Jackiw. • The path integral formulation of the two-dimensional Snyder harmonic oscillator is outlined.

  13. Leavitt path algebras

    CERN Document Server

    Abrams, Gene; Siles Molina, Mercedes

    2017-01-01

    This book offers a comprehensive introduction by three of the leading experts in the field, collecting fundamental results and open problems in a single volume. Since Leavitt path algebras were first defined in 2005, interest in these algebras has grown substantially, with ring theorists as well as researchers working in graph C*-algebras, group theory and symbolic dynamics attracted to the topic. Providing a historical perspective on the subject, the authors review existing arguments, establish new results, and outline the major themes and ring-theoretic concepts, such as the ideal structure, Z-grading and the close link between Leavitt path algebras and graph C*-algebras. The book also presents key lines of current research, including the Algebraic Kirchberg Phillips Question, various additional classification questions, and connections to noncommutative algebraic geometry. Leavitt Path Algebras will appeal to graduate students and researchers working in the field and related areas, such as C*-algebras and...

  14. Techniques and applications of path integration

    CERN Document Server

    Schulman, L S

    2005-01-01

    A book of techniques and applications, this text defines the path integral and illustrates its uses by example. It is suitable for advanced undergraduates and graduate students in physics; its sole prerequisite is a first course in quantum mechanics. For applications requiring specialized knowledge, the author supplies background material.The first part of the book develops the techniques of path integration. Topics include probability amplitudes for paths and the correspondence limit for the path integral; vector potentials; the Ito integral and gauge transformations; free particle and quadra

  15. Joint modeling of constrained path enumeration and path choice behavior: a semi-compensatory approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2010-01-01

    A behavioural and a modelling framework are proposed for representing route choice from a path set that satisfies travellers’ spatiotemporal constraints. Within the proposed framework, travellers’ master sets are constructed by path generation, consideration sets are delimited according to spatio...

  16. Sensor-Oriented Path Planning for Multiregion Surveillance with a Single Lightweight UAV SAR

    Science.gov (United States)

    Li, Jincheng; Chen, Jie; Wang, Pengbo; Li, Chunsheng

    2018-01-01

    In the surveillance of interested regions by unmanned aerial vehicle (UAV), system performance relies greatly on the motion control strategy of the UAV and the operation characteristics of the onboard sensors. This paper investigates the 2D path planning problem for the lightweight UAV synthetic aperture radar (SAR) system in an environment of multiple regions of interest (ROIs), the sizes of which are comparable to the radar swath width. Taking into account the special requirements of the SAR system on the motion of the platform, we model path planning for UAV SAR as a constrained multiobjective optimization problem (MOP). Based on the fact that the UAV route can be designed in the map image, an image-based path planner is proposed in this paper. First, the neighboring ROIs are merged by the morphological operation. Then, the parts of routes for data collection of the ROIs can be located according to the geometric features of the ROIs and the observation geometry of UAV SAR. Lastly, the route segments for ROIs surveillance are connected by a path planning algorithm named the sampling-based sparse A* search (SSAS) algorithm. Simulation experiments in real scenarios demonstrate that the proposed sensor-oriented path planner can improve the reconnaissance performance of lightweight UAV SAR greatly compared with the conventional zigzag path planner. PMID:29439447

  17. Sensor-Oriented Path Planning for Multiregion Surveillance with a Single Lightweight UAV SAR.

    Science.gov (United States)

    Li, Jincheng; Chen, Jie; Wang, Pengbo; Li, Chunsheng

    2018-02-11

    In the surveillance of interested regions by unmanned aerial vehicle (UAV), system performance relies greatly on the motion control strategy of the UAV and the operation characteristics of the onboard sensors. This paper investigates the 2D path planning problem for the lightweight UAV synthetic aperture radar (SAR) system in an environment of multiple regions of interest (ROIs), the sizes of which are comparable to the radar swath width. Taking into account the special requirements of the SAR system on the motion of the platform, we model path planning for UAV SAR as a constrained multiobjective optimization problem (MOP). Based on the fact that the UAV route can be designed in the map image, an image-based path planner is proposed in this paper. First, the neighboring ROIs are merged by the morphological operation. Then, the parts of routes for data collection of the ROIs can be located according to the geometric features of the ROIs and the observation geometry of UAV SAR. Lastly, the route segments for ROIs surveillance are connected by a path planning algorithm named the sampling-based sparse A* search (SSAS) algorithm. Simulation experiments in real scenarios demonstrate that the proposed sensor-oriented path planner can improve the reconnaissance performance of lightweight UAV SAR greatly compared with the conventional zigzag path planner.

  18. Sampling Transition Pathways in Highly Correlated Complex Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David

    2004-10-20

    This research grant supported my group's efforts to apply and extend the method of transition path sampling that we invented during the late 1990s. This methodology is based upon a statistical mechanics of trajectory space. Traditional statistical mechanics focuses on state space, and with it, one can use Monte Carlo methods to facilitate importance sampling of states. With our formulation of a statistical mechanics of trajectory space, we have succeeded at creating algorithms by which importance sampling can be done for dynamical processes. In particular, we are able to study rare but important events without prior knowledge of transition states or mechanisms. In perhaps the most impressive application of transition path sampling, my group combined forces with Michele Parrinello and his coworkers to unravel the dynamics of auto ionization of water [5]. This dynamics is the fundamental kinetic step of pH. Other applications concern nature of dynamics far from equilibrium [1, 7], nucleation processes [2], cluster isomerization, melting and dissociation [3, 6], and molecular motors [10]. Research groups throughout the world are adopting transition path sampling. In part this has been the result of our efforts to provide pedagogical presentations of the technique [4, 8, 9], as well as providing new procedures for interpreting trajectories of complex systems [11].

  19. Isomorphisms and traversability of directed path graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Li, Xueliang; Li, X.

    1998-01-01

    The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\\forw P_k(D)$ of a digraph $D$ is obtained by representing the directed paths on $k$ vertices of $D$ by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in $D$

  20. The influence of parenting style on academic achievement and career path

    Directory of Open Access Journals (Sweden)

    ZAHRA ZAHED ZAHEDANI

    2016-07-01

    Full Text Available Introduction: Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences. Methods: This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind’s Parenting Style and Moqimi’s Career Path questionnaires were used and the obtained scores were correlated with the students’ transcripts. To study the relation between variables Pearson correlation coefficient was used. Results: There was a significant relationship between authoritarian parenting style and educational success (p=0.03. Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001. Conclusion: Parents have an important role in identifying children’s talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes.

  1. The influence of parenting style on academic achievement and career path

    Science.gov (United States)

    ZAHED ZAHEDANI, ZAHRA; REZAEE, RITA; YAZDANI, ZAHRA; BAGHERI, SINA; NABEIEI, PARISA

    2016-01-01

    Introduction Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences.     Methods This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Baumrind’s Parenting Style and Moqimi’s Career Path questionnaires were used and the obtained scores were correlated with the students' transcripts. To study the relation between variables Pearson correlation coefficient was used. Results There was a significant relationship between authoritarian parenting style and educational success (p=0.03). Also findings showed a significant relationship between firm parenting style and Career Path of the students, authoritarian parenting style and Career Path of the students, educational success and Career Path of the students (p=0.001). Conclusion Parents have an important role in identifying children’s talent and guiding them. Mutual understanding and close relationship between parents and children are recommended. Therefore, it is recommended that the methods of correct interaction of parents and children be more valued and parents familiarize their children with roles of businesses in society and the need for employment in legitimate businesses and this important affair should be more emphasized through mass media and family training classes. PMID:27382580

  2. Infrastructure Development

    DEFF Research Database (Denmark)

    Williams, Idongesit

    2012-01-01

    access and service of telecommunications/ICTs have been stalled. This paper throws light on a possible Public Private Partnership framework as a development path that will enable affordable network technologies to be deployed in rural areas at a cost that will translate to what the rural dweller...

  3. Path analysis of risk factors leading to premature birth.

    Science.gov (United States)

    Fields, S J; Livshits, G; Sirotta, L; Merlob, P

    1996-01-01

    The present study tested whether various sociodemographic, anthropometric, behavioral, and medical/physiological factors act in a direct or indirect manner on the risk of prematurity using path analysis on a sample of Israeli births. The path model shows that medical complications, primarily toxemia, chorioammionitis, and a previous low birth weight delivery directly and significantly act on the risk of prematurity as do low maternal pregnancy weight gain and ethnicity. Other medical complications, including chronic hypertension, preclampsia, and placental abruption, although significantly correlated with prematurity, act indirectly on prematurity through toxemia. The model further shows that the commonly accepted sociodemographic, anthropometric, and behavioral risk factors act by modifying the development of medical complications that lead to prematurity as opposed to having a direct effect on premature delivery. © 1996 Wiley-Liss, Inc. Copyright © 1996 Wiley-Liss, Inc.

  4. Graphs with not all possible path-kernels

    DEFF Research Database (Denmark)

    Aldred, Robert; Thomassen, Carsten

    2004-01-01

    The Path Partition Conjecture states that the vertices of a graph G with longest path of length c may be partitioned into two parts X and Y such that the longest path in the subgraph of G induced by X has length at most a and the longest path in the subgraph of G induced by Y has length at most b...

  5. Design of Active N-path Filters

    NARCIS (Netherlands)

    Darvishi, M.; van der Zee, Ronan A.R.; Nauta, Bram

    2013-01-01

    A design methodology for synthesis of active N-path bandpass filters is introduced. Based on this methodology, a 0.1-to-1.2 GHz tunable 6th-order N-path channel-select filter in 65 nm LP CMOS is introduced. It is based on coupling N-path filters with gyrators, achieving a “flat‿ passband shape and

  6. Impulsive noise suppression in color images based on the geodesic digital paths

    Science.gov (United States)

    Smolka, Bogdan; Cyganek, Boguslaw

    2015-02-01

    In the paper a novel filtering design based on the concept of exploration of the pixel neighborhood by digital paths is presented. The paths start from the boundary of a filtering window and reach its center. The cost of transitions between adjacent pixels is defined in the hybrid spatial-color space. Then, an optimal path of minimum total cost, leading from pixels of the window's boundary to its center is determined. The cost of an optimal path serves as a degree of similarity of the central pixel to the samples from the local processing window. If a pixel is an outlier, then all the paths starting from the window's boundary will have high costs and the minimum one will also be high. The filter output is calculated as a weighted mean of the central pixel and an estimate constructed using the information on the minimum cost assigned to each image pixel. So, first the costs of optimal paths are used to build a smoothed image and in the second step the minimum cost of the central pixel is utilized for construction of the weights of a soft-switching scheme. The experiments performed on a set of standard color images, revealed that the efficiency of the proposed algorithm is superior to the state-of-the-art filtering techniques in terms of the objective restoration quality measures, especially for high noise contamination ratios. The proposed filter, due to its low computational complexity, can be applied for real time image denoising and also for the enhancement of video streams.

  7. PATH ANALYSIS OF RECORDING SYSTEM INNOVATION FACTORS AFFECTING ADOPTION OF GOAT FARMERS

    Directory of Open Access Journals (Sweden)

    S. Okkyla

    2014-09-01

    Full Text Available The objective of this study was to evaluate the path analysis of recording system innovation factorsaffecting adoption of goat farmers. This study was conducted from January to February 2014 inPringapus District, Semarang Regency by using survey method. For determining the location, this studyused purposive sampling method. The amount of respondents were determined by quota samplingmethod. Total respondents randomly chosed were 146 farmers. The data were descriptively andquantitatively analyzed by using path analysis of statistical package for the social science (SPSS 16.Independent variables in this study were internal factor, motivation, innovation characteristics,information source, and dependent variable was adoption. Analysis of linear regression showed thatthere was no significant effect of internal factor on adoption, so that it was important to use the trimmingmethod in path analysis. The result of path analysis showed that the influence of motivation, innovationcharacteristics and information source on adoption were 0.168; 0.720 and 0.09, respectively. Innovationcharacteristics were the greatest effect on adoption. In conclusion, by improving innovationcharacteristics of respondent through motivation and information source may significantly increase theadoption of recording system in goat farmers.

  8. Path integrals and geometry of trajectories

    International Nuclear Information System (INIS)

    Blau, M.; Keski-Vakkuri, E.; Niemi, A.J.

    1990-01-01

    A geometrical interpretation of path integrals is developed in the space of trajectories. This yields a supersymmetric formulation of a generic path integral, with the supersymmetry resembling the BRST supersymmetry of a first class constrained system. If the classical equation of motion is a Killing vector field in the space of trajectories, the supersymmetry localizes the path integral to classical trajectories and the WKB approximation becomes exact. This can be viewed as a path integral generalization of the Duistermaat-Heckman theorem, which states the conditions for the exactness of the WKB approximation for integrals in a compact phase space. (orig.)

  9. Perfect discretization of path integrals

    International Nuclear Information System (INIS)

    Steinhaus, Sebastian

    2012-01-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  10. Perfect discretization of path integrals

    Science.gov (United States)

    Steinhaus, Sebastian

    2012-05-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discussed. Furthermore we show that a reparametrization invariant path integral implies discretization independence and acts as a projector onto physical states.

  11. Efficacy of using multiple open-path Fourier transform infrared (OP-FTIR) spectrometers in an odor emission episode investigation at a semiconductor manufacturing plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, Yung-Chieh; Wu, Chang-Fu [Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei City 100, Taiwan (China); Chang, Pao-Erh; Chen, Shin-Yu [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu City 310, Taiwan 310 (China); Hwang, Yaw-Huei, E-mail: yhhwang@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei City 100, Taiwan (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei City 100, Taiwan (China)

    2011-08-01

    This study evaluated the efficacy of simultaneously employing three open-path Fourier transform infrared (OP-FTIR) spectrometers with 3-day consecutive monitoring, using an odor episode as an example. The corresponding monitoring paths were allocated among the possible emission sources of a semiconductor manufacturing plant and the surrounding optoelectronic and electronic-related factories, which were located in a high-tech industrial park. There was a combined total odor rate of 43.9% for the three monitoring paths, each comprised of 736 continuous 5-minute monitoring records and containing detectable odor compounds, such as ammonia, ozone, butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA). The results of the logistic regression model indicated that the prevailing south wind and the OP-FTIR monitoring path closest to the emission source in down-wind direction resulted in a high efficacy for detecting odorous samples with odds ratios (OR) of 3.8 (95% confidence interval (CI): 2.9-5.0) and 5.1 (95% CI: 3.6-7.2), respectively. Meanwhile, the odds ratio for detecting ammonia odorous samples was 7.5 for Path II, which was downwind closer to the possible source, as compared to Path III, downwind far away from the possible source. PGMEA could not be monitored at Path II but could be at Path III, indicating the importance of the monitoring path and flow ejection velocities inside the stacks on the monitoring performance of OP-FTIR. Besides, an odds ratio of 5.1 for odorous sample detection was obtained with south prevailing wind comprising 65.0% of the monitoring time period. In general, it is concluded that OP-FTIR operated with multiple paths simultaneously shall be considered for investigation on relatively complicated episodes such as emergency of chemical release, multiple-source emission and chemical monitoring for odor in a densely populated plant area to enhance the efficacy of OP-FTIR monitoring. - Research highlights: {yields} To conduct

  12. Efficacy of using multiple open-path Fourier transform infrared (OP-FTIR) spectrometers in an odor emission episode investigation at a semiconductor manufacturing plant

    International Nuclear Information System (INIS)

    Tsao, Yung-Chieh; Wu, Chang-Fu; Chang, Pao-Erh; Chen, Shin-Yu; Hwang, Yaw-Huei

    2011-01-01

    This study evaluated the efficacy of simultaneously employing three open-path Fourier transform infrared (OP-FTIR) spectrometers with 3-day consecutive monitoring, using an odor episode as an example. The corresponding monitoring paths were allocated among the possible emission sources of a semiconductor manufacturing plant and the surrounding optoelectronic and electronic-related factories, which were located in a high-tech industrial park. There was a combined total odor rate of 43.9% for the three monitoring paths, each comprised of 736 continuous 5-minute monitoring records and containing detectable odor compounds, such as ammonia, ozone, butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA). The results of the logistic regression model indicated that the prevailing south wind and the OP-FTIR monitoring path closest to the emission source in down-wind direction resulted in a high efficacy for detecting odorous samples with odds ratios (OR) of 3.8 (95% confidence interval (CI): 2.9-5.0) and 5.1 (95% CI: 3.6-7.2), respectively. Meanwhile, the odds ratio for detecting ammonia odorous samples was 7.5 for Path II, which was downwind closer to the possible source, as compared to Path III, downwind far away from the possible source. PGMEA could not be monitored at Path II but could be at Path III, indicating the importance of the monitoring path and flow ejection velocities inside the stacks on the monitoring performance of OP-FTIR. Besides, an odds ratio of 5.1 for odorous sample detection was obtained with south prevailing wind comprising 65.0% of the monitoring time period. In general, it is concluded that OP-FTIR operated with multiple paths simultaneously shall be considered for investigation on relatively complicated episodes such as emergency of chemical release, multiple-source emission and chemical monitoring for odor in a densely populated plant area to enhance the efficacy of OP-FTIR monitoring. - Research highlights: → To conduct multi-path

  13. On Hilbert space of paths

    International Nuclear Information System (INIS)

    Exner, P.; Kolerov, G.I.

    1980-01-01

    A Hilbert space of paths, the elements of which are determined by trigonometric series, was proposed and used recently by Truman. This space is shown to consist precisely of all absolutely continuous paths ending in the origin with square-integrable derivatives

  14. Tool path in torus tool CNC machining

    Directory of Open Access Journals (Sweden)

    XU Ying

    2016-10-01

    Full Text Available This paper is about tool path in torus tool CNC machining.The mathematical model of torus tool is established.The tool path planning algorithm is determined through calculation of the cutter location,boundary discretization,calculation of adjacent tool path and so on,according to the conversion formula,the cutter contact point will be converted to the cutter location point and then these points fit a toolpath.Lastly,the path planning algorithm is implemented by using Matlab programming.The cutter location points for torus tool are calculated by Matlab,and then fit these points to a toolpath.While using UG software,another tool path of free surface is simulated of the same data.It is drew compared the two tool paths that using torus tool is more efficient.

  15. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

  16. Foundations and latest advances in replica exchange transition interface sampling

    Science.gov (United States)

    Cabriolu, Raffaela; Skjelbred Refsnes, Kristin M.; Bolhuis, Peter G.; van Erp, Titus S.

    2017-10-01

    Nearly 20 years ago, transition path sampling (TPS) emerged as an alternative method to free energy based approaches for the study of rare events such as nucleation, protein folding, chemical reactions, and phase transitions. TPS effectively performs Monte Carlo simulations with relatively short molecular dynamics trajectories, with the advantage of not having to alter the actual potential energy surface nor the underlying physical dynamics. Although the TPS approach also introduced a methodology to compute reaction rates, this approach was for a long time considered theoretically attractive, providing the exact same results as extensively long molecular dynamics simulations, but still expensive for most relevant applications. With the increase of computer power and improvements in the algorithmic methodology, quantitative path sampling is finding applications in more and more areas of research. In particular, the transition interface sampling (TIS) and the replica exchange TIS (RETIS) algorithms have, in turn, improved the efficiency of quantitative path sampling significantly, while maintaining the exact nature of the approach. Also, open-source software packages are making these methods, for which implementation is not straightforward, now available for a wider group of users. In addition, a blooming development takes place regarding both applications and algorithmic refinements. Therefore, it is timely to explore the wide panorama of the new developments in this field. This is the aim of this article, which focuses on the most efficient exact path sampling approach, RETIS, as well as its recent applications, extensions, and variations.

  17. [Experimental studies on the wounding capacity of recently developed shuriken/throwing stars and their legal categorization--an interdisciplinary view].

    Science.gov (United States)

    Kettner, Mattias; Gade, Gunther; Ramsthaler, Frank; Shah, Sanjai; Pape, Andreas; Theisen, Alf; Schmidt, Peter

    2010-01-01

    Shuriken/throwing stars are traditional Japanese weapons for close combat situations. They vary greatly in shape and mode of action. Due to their wounding capacity traditional shuriken made of steel were prohibited in Germany in the 1980's. In the present study three recently developed types of shuriken were examined to determine their wounding capacity. Type 1 was made of plastic, whereas type 2 was a so-called cyclone shuriken equipped with three knives protruding from a discoidal center due to centrifugal force during the flight. Type 3 consisted of three traditional metal shuriken with blunt edges and peaks produced for decorative purposes. Experiments using pig carcasses were carried out for types 1 and 2. An experiment using human skin was performed with type 3 shuriken. An experienced thrower performed throws from a distance of 1, 2, 3, and 4 m with the shuriken made of plastic. For the cyclone shuriken a distance of 4 m was chosen to ensure the unfolding of the shuriken during flight. Type 3 shuriken were tested using a distance of 2 m. Penetration depths of the shuriken made of plastic reached up to 8 mm in pig skin. The experiment with the cyclone shuriken revealed a penetration depth of up to 2.5 cm cutting through the entire abdominal tissue and opening up an intestinal loop whereas type 3 shuriken yielded maximal penetration depths between 0.9 and 2.3 cm. This study indicates that all three types of shuriken may inflict lethal wounds upon opponents in close combat. The findings of this study should promote a public discussion whether the ban on traditional shuriken should be extended to the recently developed types.

  18. Medical Ethics in Qiṣāṣ (Eye-for-an-Eye) Punishment: An Islamic View; an Examination of Acid Throwing.

    Science.gov (United States)

    Alishahi Tabriz, Amir; Dabbagh, Hossein; Koenig, Harold G

    2016-08-01

    Physicians in Islamic countries might be requested to participate in the Islamic legal code of qiṣāṣ, in which the victim or family has the right to an eye-for-an-eye retaliation. Qiṣāṣ is only used as a punishment in the case of murder or intentional physical injury. In situations such as throwing acid, the national legal system of some Islamic countries asks for assistance from physicians, because the punishment should be identical to the crime. The perpetrator could not be punished without a physician's participation, because there is no way to guarantee that the sentence would be carried out without inflicting more injury than the initial victim had suffered. By examining two cases of acid throwing, this paper discusses issues related to physicians' participation in qiṣāṣ from the perspective of medical ethics and Islamic Shari'a law. From the standpoint of medical ethics, physicians' participation in qiṣāṣ is not appropriate. First, qiṣāṣ is in sharp contrast to the Hippocratic Oath and other codes of medical ethics. Second, by physicians' participation in qiṣāṣ, medical practices are being used improperly to carry out government mandates. Third, physician participation in activities that cause intentional harm to people destroys the trust between patients and physicians and may adversely affect the patient-physician relationship more generally. From the standpoint of Shari'a, there is no consensus among Muslim scholars whether qiṣāṣ should be performed on every occasion. We argue that disallowing physician involvement in qiṣāṣ is necessary from the perspectives of both medical ethics and Shari'a law.

  19. Constrained approximation of effective generators for multiscale stochastic reaction networks and application to conditioned path sampling

    Energy Technology Data Exchange (ETDEWEB)

    Cotter, Simon L., E-mail: simon.cotter@manchester.ac.uk

    2016-10-15

    Efficient analysis and simulation of multiscale stochastic systems of chemical kinetics is an ongoing area for research, and is the source of many theoretical and computational challenges. In this paper, we present a significant improvement to the constrained approach, which is a method for computing effective dynamics of slowly changing quantities in these systems, but which does not rely on the quasi-steady-state assumption (QSSA). The QSSA can cause errors in the estimation of effective dynamics for systems where the difference in timescales between the “fast” and “slow” variables is not so pronounced. This new application of the constrained approach allows us to compute the effective generator of the slow variables, without the need for expensive stochastic simulations. This is achieved by finding the null space of the generator of the constrained system. For complex systems where this is not possible, or where the constrained subsystem is itself multiscale, the constrained approach can then be applied iteratively. This results in breaking the problem down into finding the solutions to many small eigenvalue problems, which can be efficiently solved using standard methods. Since this methodology does not rely on the quasi steady-state assumption, the effective dynamics that are approximated are highly accurate, and in the case of systems with only monomolecular reactions, are exact. We will demonstrate this with some numerics, and also use the effective generators to sample paths of the slow variables which are conditioned on their endpoints, a task which would be computationally intractable for the generator of the full system.

  20. How to solve path integrals in quantum mechanics

    International Nuclear Information System (INIS)

    Grosche, C.

    1994-10-01

    A systematic classification of Feynman path integrals in quantum mechanics is presented and a table of solvable path integrals is given which reflects the progress made during the last 15 years, including, of course, the main contributions since the invention of the path integral by Feynman in 1942. An outline of the general theory is given which will serve as a quick reference for solving path integrals. Explicit formulae for the so-called basic path integrals are presented on which our general scheme to classify and calculate path integrals in quantum mechanics is based. (orig.)

  1. Path integrals for arbitrary canonical transformations

    International Nuclear Information System (INIS)

    Oliveira, L.A.R. de.

    1980-01-01

    Some aspects of the path integral formulation of quantum mechanics are studied. This formalism is generalized to arbitrary canonical transformations, by means of an association between path integral probalility amplitudes and classical generators of transformations, analogous to the usual Hamiltonian time development phase space expression. Such association turns out to be equivalent to the Weyl quantization rule, and it is also shown that this formalism furnishes a path integral representation for a Lie algebra of a given set of classical generators. Some physical considerations about the path integral quantization procedure and about the relationship between classical and quantum dynamical structures are also discussed. (Author) [pt

  2. Path Planning Algorithms for the Adaptive Sensor Fleet

    Science.gov (United States)

    Stoneking, Eric; Hosler, Jeff

    2005-01-01

    The Adaptive Sensor Fleet (ASF) is a general purpose fleet management and planning system being developed by NASA in coordination with NOAA. The current mission of ASF is to provide the capability for autonomous cooperative survey and sampling of dynamic oceanographic phenomena such as current systems and algae blooms. Each ASF vessel is a software model that represents a real world platform that carries a variety of sensors. The OASIS platform will provide the first physical vessel, outfitted with the systems and payloads necessary to execute the oceanographic observations described in this paper. The ASF architecture is being designed for extensibility to accommodate heterogenous fleet elements, and is not limited to using the OASIS platform to acquire data. This paper describes the path planning algorithms developed for the acquisition phase of a typical ASF task. Given a polygonal target region to be surveyed, the region is subdivided according to the number of vessels in the fleet. The subdivision algorithm seeks a solution in which all subregions have equal area and minimum mean radius. Once the subregions are defined, a dynamic programming method is used to find a minimum-time path for each vessel from its initial position to its assigned region. This path plan includes the effects of water currents as well as avoidance of known obstacles. A fleet-level planning algorithm then shuffles the individual vessel assignments to find the overall solution which puts all vessels in their assigned regions in the minimum time. This shuffle algorithm may be described as a process of elimination on the sorted list of permutations of a cost matrix. All these path planning algorithms are facilitated by discretizing the region of interest onto a hexagonal tiling.

  3. An initial examination of tungsten geochemistry along groundwater flow paths

    Science.gov (United States)

    Dave, H. B.; Johannesson, K. H.

    2008-12-01

    Groundwater samples were collected along groundwater flow paths from the Upper Floridan (Florida), Carrizo Sand (Texas), and the Aquia (Maryland) aquifers and analyzed for tungsten (W) concentrations by high- resolution inductively couple plasma mass spectrometry. At each well head, groundwater samples were also analyzed for pH, specific conductance, temperature, alkalinity, dissolved oxygen (DO), oxidation-reduction potential (Eh), dissolved iron speciation, and dissolved sulfide [S(-II)] concentrations. Sediment samples from the Carrizo Sand and Aquia aquifers were also collected and subjected to sequential extractions to provide additional insights into the solid-phase speciation of W in these aquifers. Tungsten concentrations varied along the groundwater flow paths chiefly in response to changing pH, and to a lesser extent, variations in the redox conditions. For groundwater from the Carrizo Sand aquifer, W ranges between 3.64 and 1297 pmol/kg, exhibiting the lowest values proximal to the recharge zone. Tungsten concentrations progressively increase along the flow path, reaching 1297 pmol/kg in the sulfidic groundwaters located approximately 60 km downgradient from the recharge area. Tungsten is strongly correlated with S(-II) concentrations and pH in Carrizo groundwaters (r = 0.95 and 0.78, respectively). Within the Aquia aquifer, however, W generally occurs at lower concentrations than the Carrizo (14 to 184 pmol/kg; mean = 80 pmol/kg), and shows no systematic trends along the flow path (e.g., r = 0.08 and 0.4 for W vs. S(-II) and pH, respectively). Our data are consistent with the increase in W concentrations in Carrizo groundwaters reflecting, in part, pH-related desorption, which has been shown to be substantial for pH greater than 8. Moreover, because of the broad similarities in the chemistry of W and Mo, which forms thiomolybdates in sulfidic waters, we suggest that thiotungstate complexes may form in sulfidic groundwaters, thus partially explaining the

  4. The strain path dependence of plastic deformation response of AA5754: Experiment and modeling

    International Nuclear Information System (INIS)

    Pham, Minh-Son; Hu, Lin; Iadicola, Mark; Creuziger, Adam; Rollett, Anthony D.

    2013-01-01

    This work presents modeling of experiments on a balanced biaxial (BB) pre-strained AA5754 alloy, subsequently reloaded uniaxially along the rolling direction and transverse direction. The material exhibits a complex plastic deformation response during the change in strain path due to 1) crystallographic texture, 2) aging (interactions between dislocations and Mg atoms) and 3) recovery (annihilation and re-arrangement of dislocations). With a BB prestrain of about 5 %, the aging process is dominant, and the yield strength for uniaxially deformed samples is observed to be higher than the flow stress during BB straining. The strain hardening rate after changing path is, however, lower than that for pre-straining. Higher degrees of pre-straining make the dynamic recovery more active. The dynamic recovery at higher strain levels compensates for the aging effect, and results in: 1) a reduction of the yield strength, and 2) an increase in the hardening rate of re-strained specimens along other directions. The yield strength of deformed samples is further reduced if these samples are left at room temperature to let static recovery occur. The synergistic influences of texture condition, aging and recovery processes on the material response make the modeling of strain path dependence of mechanical behavior of AA5754 challenging. In this study, the influence of crystallographic texture is taken into account by incorporating the latent hardening into a visco-plastic self-consistent model. Different strengths of dislocation glide interaction models in 24 slip systems are used to represent the latent hardening. Moreover, the aging and recovery effects are also included into the latent hardening model by considering strong interactions between dislocations and dissolved atom Mg and the microstructural evolution. These microstructural considerations provide a powerful capability to successfully describe the strain path dependence of plastic deformation behavior of AA5754

  5. Developing Students' Reasoning about Samples and Sampling Variability as a Path to Expert Statistical Thinking

    Science.gov (United States)

    Garfield, Joan; Le, Laura; Zieffler, Andrew; Ben-Zvi, Dani

    2015-01-01

    This paper describes the importance of developing students' reasoning about samples and sampling variability as a foundation for statistical thinking. Research on expert-novice thinking as well as statistical thinking is reviewed and compared. A case is made that statistical thinking is a type of expert thinking, and as such, research…

  6. An Empirical Path-Loss Model for Wireless Channels in Indoor Short-Range Office Environment

    Directory of Open Access Journals (Sweden)

    Ye Wang

    2012-01-01

    Full Text Available A novel empirical path-loss model for wireless indoor short-range office environment at 4.3–7.3 GHz band is presented. The model is developed based on the experimental datum sampled in 30 office rooms in both line of sight (LOS and non-LOS (NLOS scenarios. The model is characterized as the path loss to distance with a Gaussian random variable X due to the shadow fading by using linear regression. The path-loss exponent n is fitted by the frequency using power function and modeled as a frequency-dependent Gaussian variable as the standard deviation σ of X. The presented works should be available for the research of wireless channel characteristics under universal indoor short-distance environments in the Internet of Things (IOT.

  7. UMAPRM: Uniformly sampling the medial axis

    KAUST Repository

    Yeh, Hsin-Yi Cindy; Denny, Jory; Lindsey, Aaron; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. Maintaining clearance, or distance from obstacles, is a vital component of successful motion planning algorithms. Maintaining high clearance often creates safer paths for robots. Contemporary sampling-based planning algorithms

  8. Path Integral Formulation of Anomalous Diffusion Processes

    OpenAIRE

    Friedrich, Rudolf; Eule, Stephan

    2011-01-01

    We present the path integral formulation of a broad class of generalized diffusion processes. Employing the path integral we derive exact expressions for the path probability densities and joint probability distributions for the class of processes under consideration. We show that Continuous Time Random Walks (CTRWs) are included in our framework. A closed expression for the path probability distribution of CTRWs is found in terms of their waiting time distribution as the solution of a Dyson ...

  9. Strategic Team AI Path Plans: Probabilistic Pathfinding

    Directory of Open Access Journals (Sweden)

    Tng C. H. John

    2008-01-01

    Full Text Available This paper proposes a novel method to generate strategic team AI pathfinding plans for computer games and simulations using probabilistic pathfinding. This method is inspired by genetic algorithms (Russell and Norvig, 2002, in that, a fitness function is used to test the quality of the path plans. The method generates high-quality path plans by eliminating the low-quality ones. The path plans are generated by probabilistic pathfinding, and the elimination is done by a fitness test of the path plans. This path plan generation method has the ability to generate variation or different high-quality paths, which is desired for games to increase replay values. This work is an extension of our earlier work on team AI: probabilistic pathfinding (John et al., 2006. We explore ways to combine probabilistic pathfinding and genetic algorithm to create a new method to generate strategic team AI pathfinding plans.

  10. An Intrinsic Algorithm for Parallel Poisson Disk Sampling on Arbitrary Surfaces.

    Science.gov (United States)

    Ying, Xiang; Xin, Shi-Qing; Sun, Qian; He, Ying

    2013-03-08

    Poisson disk sampling plays an important role in a variety of visual computing, due to its useful statistical property in distribution and the absence of aliasing artifacts. While many effective techniques have been proposed to generate Poisson disk distribution in Euclidean space, relatively few work has been reported to the surface counterpart. This paper presents an intrinsic algorithm for parallel Poisson disk sampling on arbitrary surfaces. We propose a new technique for parallelizing the dart throwing. Rather than the conventional approaches that explicitly partition the spatial domain to generate the samples in parallel, our approach assigns each sample candidate a random and unique priority that is unbiased with regard to the distribution. Hence, multiple threads can process the candidates simultaneously and resolve conflicts by checking the given priority values. It is worth noting that our algorithm is accurate as the generated Poisson disks are uniformly and randomly distributed without bias. Our method is intrinsic in that all the computations are based on the intrinsic metric and are independent of the embedding space. This intrinsic feature allows us to generate Poisson disk distributions on arbitrary surfaces. Furthermore, by manipulating the spatially varying density function, we can obtain adaptive sampling easily.

  11. Two Generations of Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

      Even if there is no fully articulated and generally accepted theory of Path Dependence it has eagerly been taken up across a wide range of social sciences - primarily coming from economics. Path Dependence is most of all a metaphor that offers reason to believe, that some political, social...

  12. Partial Path Column Generation for the ESPPRC

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn

    This talk introduces a decomposition of the Elementary Shortest Path Problem with Resource Constraints(ESPPRC), where the path is combined by smaller sub paths. We show computational result by comparing different approaches for the decomposition and compare the best of these with existing algorit...

  13. Ballistic electron transport in mesoscopic samples

    International Nuclear Information System (INIS)

    Diaconescu, D.

    2000-01-01

    In the framework of this thesis, the electron transport in the ballistic regime has been studied. Ballistic means that the lateral sample dimensions are smaller than the mean free path of the electrons, i.e. the electrons can travel through the whole device without being scattered. This leads to transport characteristics that differ significantly from the diffusive regime which is realised in most experiments. Making use of samples with high mean free path, features of ballistic transport have been observed on samples with sizes up to 100 μm. The basic device used in ballistic electron transport is the point contact, from which a collimated beam of ballistic electrons can be injected. Such point contacts were realised with focused ion beam (FIB) implantation and the collimating properties were analysed using a two opposite point contact configuration. The typical angular width at half maximum is around 50 , which is comparable with that of point contacts defined by other methods. (orig.)

  14. Investigation of the influence of sampling schemes on quantitative dynamic fluorescence imaging.

    Science.gov (United States)

    Dai, Yunpeng; Chen, Xueli; Yin, Jipeng; Wang, Guodong; Wang, Bo; Zhan, Yonghua; Nie, Yongzhan; Wu, Kaichun; Liang, Jimin

    2018-04-01

    Dynamic optical data from a series of sampling intervals can be used for quantitative analysis to obtain meaningful kinetic parameters of probe in vivo . The sampling schemes may affect the quantification results of dynamic fluorescence imaging. Here, we investigate the influence of different sampling schemes on the quantification of binding potential ( BP ) with theoretically simulated and experimentally measured data. Three groups of sampling schemes are investigated including the sampling starting point, sampling sparsity, and sampling uniformity. In the investigation of the influence of the sampling starting point, we further summarize two cases by considering the missing timing sequence between the probe injection and sampling starting time. Results show that the mean value of BP exhibits an obvious growth trend with an increase in the delay of the sampling starting point, and has a strong correlation with the sampling sparsity. The growth trend is much more obvious if throwing the missing timing sequence. The standard deviation of BP is inversely related to the sampling sparsity, and independent of the sampling uniformity and the delay of sampling starting time. Moreover, the mean value of BP obtained by uniform sampling is significantly higher than that by using the non-uniform sampling. Our results collectively suggest that a suitable sampling scheme can help compartmental modeling of dynamic fluorescence imaging provide more accurate results and simpler operations.

  15. Effect of Tool-Path on Morphology and Mechanical Properties of Ti-6Al-4V Fabricated by Wire and Arc Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Fu Jie

    2017-01-01

    Full Text Available Ti-6Al-4V components are widely used in aerospace industry. However, it’s not economic to manufacture them in traditional subtractive methods. Wire and arc additive manufacturing (WAAM is a promising alternative technology for fabricating it efficiently and economically. Tool-path planning strategy is a very important step in WAAM process. This paper investigated the influence of the lap way between layers and layers in tool-path on the Ti-6Al-4V samples fabricated by WAAM. It has been found that the lap way between layers and layers in tool-path do influence the forming quality and especially mechanical properties of the fabricated samples. Samples have different surface quality (smooth or undulating and defects inside or on the surface of the components. The highest and smallest ultra tensile strength of the fabricated samples are respectively 907.86 MPa, 684.82 MPa. But it has few effect on the grains of the fabricated samples, and they all have cross-sectional columnar grains.

  16. Path integration on hyperbolic spaces

    Energy Technology Data Exchange (ETDEWEB)

    Grosche, C [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    1991-11-01

    Quantum mechanics on the hyperbolic spaces of rank one is discussed by path integration technique. Hyperbolic spaces are multi-dimensional generalisation of the hyperbolic plane, i.e. the Poincare upper half-plane endowed with a hyperbolic geometry. We evalute the path integral on S{sub 1} {approx equal} SO (n,1)/SO(n) and S{sub 2} {approx equal} SU(n,1)/S(U(1) x U(n)) in a particular coordinate system, yielding explicitly the wave-functions and the energy spectrum. Futhermore we can exploit a general property of all these spaces, namely that they can be parametrized by a pseudopolar coordinate system. This allows a separation in path integration over spheres and an additional path integration over the remaining hyperbolic coordinate, yielding effectively a path integral for a modified Poeschl-Teller potential. Only continuous spectra can exist in all the cases. For all the hyperbolic spaces of rank one we find a general formula for the largest lower bound (zero-point energy) of the spectrum which is given by E{sub O} = h{sup 2} /8m(m{sub {alpha}} +2m{sub 2} {alpha}){sup 2} (m {alpha} and m{sub 2}{alpha} denote the dimension of the root subspace corresponding to the roots {alpha} and 2{alpha}, respectively). I also discuss the case, where a constant magnetic field on H{sup n} is incorporated. (orig.).

  17. Path integration on hyperbolic spaces

    International Nuclear Information System (INIS)

    Grosche, C.

    1991-11-01

    Quantum mechanics on the hyperbolic spaces of rank one is discussed by path integration technique. Hyperbolic spaces are multi-dimensional generalisation of the hyperbolic plane, i.e. the Poincare upper half-plane endowed with a hyperbolic geometry. We evalute the path integral on S 1 ≅ SO (n,1)/SO(n) and S 2 ≅ SU(n,1)/S[U(1) x U(n)] in a particular coordinate system, yielding explicitly the wave-functions and the energy spectrum. Futhermore we can exploit a general property of all these spaces, namely that they can be parametrized by a pseudopolar coordinate system. This allows a separation in path integration over spheres and an additional path integration over the remaining hyperbolic coordinate, yielding effectively a path integral for a modified Poeschl-Teller potential. Only continuous spectra can exist in all the cases. For all the hyperbolic spaces of rank one we find a general formula for the largest lower bound (zero-point energy) of the spectrum which is given by E O = h 2 /8m(m α +2m 2 α) 2 (m α and m 2 α denote the dimension of the root subspace corresponding to the roots α and 2α, respectively). I also discuss the case, where a constant magnetic field on H n is incorporated. (orig.)

  18. Improved initial guess for minimum energy path calculations

    International Nuclear Information System (INIS)

    Smidstrup, Søren; Pedersen, Andreas; Stokbro, Kurt; Jónsson, Hannes

    2014-01-01

    A method is presented for generating a good initial guess of a transition path between given initial and final states of a system without evaluation of the energy. An objective function surface is constructed using an interpolation of pairwise distances at each discretization point along the path and the nudged elastic band method then used to find an optimal path on this image dependent pair potential (IDPP) surface. This provides an initial path for the more computationally intensive calculations of a minimum energy path on an energy surface obtained, for example, by ab initio or density functional theory. The optimal path on the IDPP surface is significantly closer to a minimum energy path than a linear interpolation of the Cartesian coordinates and, therefore, reduces the number of iterations needed to reach convergence and averts divergence in the electronic structure calculations when atoms are brought too close to each other in the initial path. The method is illustrated with three examples: (1) rotation of a methyl group in an ethane molecule, (2) an exchange of atoms in an island on a crystal surface, and (3) an exchange of two Si-atoms in amorphous silicon. In all three cases, the computational effort in finding the minimum energy path with DFT was reduced by a factor ranging from 50% to an order of magnitude by using an IDPP path as the initial path. The time required for parallel computations was reduced even more because of load imbalance when linear interpolation of Cartesian coordinates was used

  19. Path Complexity in Virtual Water Maze Navigation: Differential Associations with Age, Sex, and Regional Brain Volume.

    Science.gov (United States)

    Daugherty, Ana M; Yuan, Peng; Dahle, Cheryl L; Bender, Andrew R; Yang, Yiqin; Raz, Naftali

    2015-09-01

    Studies of human navigation in virtual maze environments have consistently linked advanced age with greater distance traveled between the start and the goal and longer duration of the search. Observations of search path geometry suggest that routes taken by older adults may be unnecessarily complex and that excessive path complexity may be an indicator of cognitive difficulties experienced by older navigators. In a sample of healthy adults, we quantify search path complexity in a virtual Morris water maze with a novel method based on fractal dimensionality. In a two-level hierarchical linear model, we estimated improvement in navigation performance across trials by a decline in route length, shortening of search time, and reduction in fractal dimensionality of the path. While replicating commonly reported age and sex differences in time and distance indices, a reduction in fractal dimension of the path accounted for improvement across trials, independent of age or sex. The volumes of brain regions associated with the establishment of cognitive maps (parahippocampal gyrus and hippocampus) were related to path dimensionality, but not to the total distance and time. Thus, fractal dimensionality of a navigational path may present a useful complementary method of quantifying performance in navigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. PTRACK: A particle tracking program for evaluation travel path/travel time uncertainties

    International Nuclear Information System (INIS)

    Thompson, B.M.; Campbell, J.E.; Longsine, D.E.

    1987-12-01

    PTRACK is a model which tracks the path of a radionuclide particle released from a nuclear waste repository into a ground-water flow system in a two-dimensional representation of stratified geologic medium. The code calculates the time required for the particle to travel from the release point (the edge of the disturbed zone) to the specified horizontal or vertical boundary (the accessible environment). The physical properties of the geologic setting and the ground-water flow system can be treated as fixed values or as random variables sampled from their respective probability distributions. In the latter case, PTRACK assigns a sampled value for each parameter and tracks a particle for this trial (realization) of the system. Repeated realizations allow the effects of parameter uncertainty on travel paths/travel times to be quantified. The code can also calculate partial correlation coefficients between dependent variables and independent variables, which are useful in identifying important independent variables. This documentation describes the mathematical basis for the model, the algorithms and solution techniques used, and the computer code design. It also contains a detailed user's manual. The implementation of PTRACK is verified with several systems for which solutions have been calculated by hand. The integration of PTRACK with a Latin hypercube sampling (LHS) code is also discussed, although other sampling methods can be employed in place of LHS. 11 refs., 14 figs., 22 tabs

  1. Path Integration on the Upper Half-Plane

    OpenAIRE

    Reijiro, KUBO; Research Institute for Theoretical Physics Hiroshima University

    1987-01-01

    Feynman's path integral is considered on the Poincare upper half-plane. It is shown that the fundamental solution to the heat equation ∂f/∂t=Δ_Hf can be expressed in terms of a path integral. A simple relation between the path integral and the Selberg trace formula is discussed briefly.

  2. Pedestrian paths: why path-dependence theory leaves health policy analysis lost in space.

    Science.gov (United States)

    Brown, Lawrence D

    2010-08-01

    Path dependence, a model first advanced to explain puzzles in the diffusion of technology, has lately won allegiance among analysts of the politics of public policy, including health care policy. Though the central premise of the model--that past events and decisions shape options for innovation in the present and future--is indisputable (indeed path dependence is, so to speak, too shallow to be false), the approach, at least as applied to health policy, suffers from ambiguities that undercut its claims to illuminate policy projects such as managed care, on which this article focuses. Because path dependence adds little more than marginal value to familiar images of the politics of policy--incrementalism, for one--analysts might do well to put it on the back burner and pursue instead "thick descriptions" that help them to distinguish different degrees of openness to exogenous change among diverse policy arenas.

  3. The Thinnest Path Problem

    Science.gov (United States)

    2016-07-22

    be reduced to TP in -D UDH for any . We then show that the 2-D disk hypergraph constructed in the proof of Theorem 1 can be modified to an exposed...transmission range that induces hy- peredge , i.e., (3) GAO et al.: THINNEST PATH PROBLEM 1181 Theorem 5 shows that the covered area of the path...representation of (the two hyperedges rooted at from the example given in Fig. 6 are illustrated in green and blue, respectively). step, we show in this

  4. Curvature-Continuous 3D Path-Planning Using QPMI Method

    Directory of Open Access Journals (Sweden)

    Seong-Ryong Chang

    2015-06-01

    Full Text Available It is impossible to achieve vertex movement and rapid velocity control in aerial robots and aerial vehicles because of momentum from the air. A continuous-curvature path ensures such robots and vehicles can fly with stable and continuous movements. General continuous path-planning methods use spline interpolation, for example B-spline and Bézier curves. However, these methods cannot be directly applied to continuous path planning in a 3D space. These methods use a subset of the waypoints to decide curvature and some waypoints are not included in the planned path. This paper proposes a method for constructing a curvature-continuous path in 3D space that includes every waypoint. The movements in each axis, x, y and z, are separated by the parameter u. Waypoint groups are formed, each with its own continuous path derived using quadratic polynomial interpolation. The membership function then combines each continuous path into one continuous path. The continuity of the path is verified and the curvature-continuous path is produced using the proposed method.

  5. Path integration on the upper half-plane

    International Nuclear Information System (INIS)

    Kubo, Reijiro.

    1987-06-01

    Feynman's path integral is considered on the Poincare upper half-plane. It is shown that the fundamental solution to the heat equation δf/δt = Δ H f can be expressed in terms of a path integral. A simple relation between the path integral and the Selberg trace formula is discussed briefly. (author)

  6. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  7. In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes.

    Science.gov (United States)

    Singh, Kanwarpal; Reddy, Rohith; Sharma, Gargi; Verma, Yogesh; Gardecki, Joseph A; Tearney, Guillermo

    2018-03-01

    Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test the designed probe in a cadaver human coronary artery ex vivo. We achieved a sensitivity of 104 dB for this probe using a swept source optical coherence tomography system. To test the probe, images of a cadaver human coronary artery were obtained, demonstrating the quality that is comparable to those obtained by OCT systems with separate reference arms. Additionally, we demonstrate recovery of ranging depth by use of a Michelson interferometer in the detection path. We developed a miniaturized monolithic inline fiber mirror-based common path probe for optical coherence tomography. Owing to its simplicity, our design will be helpful in endoscopic applications that require high-resolution probes in a compact form factor while reducing system complexity. Lasers Surg. Med. 50:230-235, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Career paths in physicians' postgraduate training - an eight-year follow-up study.

    Science.gov (United States)

    Buddeberg-Fischer, Barbara; Stamm, Martina; Klaghofer, Richard

    2010-10-06

    To date, there are hardly any studies on the choice of career path in medical school graduates. The present study aimed to investigate what career paths can be identified in the course of postgraduate training of physicians; what factors have an influence on the choice of a career path; and in what way the career paths are correlated with career-related factors as well as with work-life balance aspirations. The data reported originates from five questionnaire surveys of the prospective SwissMedCareer Study, beginning in 2001 (T1, last year of medical school). The study sample consisted of 358 physicians (197 females, 55%; 161 males, 45%) participating at each assessment from T2 (2003, first year of residency) to T5 (2009, seventh year of residency), answering the question: What career do you aspire to have? Furthermore, personal characteristics, chosen specialty, career motivation, mentoring experience, work-life balance as well as workload, career success and career satisfaction were assessed. Career paths were analysed with cluster analysis, and differences between clusters analysed with multivariate methods. The cluster analysis revealed four career clusters which discriminated distinctly between each other: (1) career in practice, (2) hospital career, (3) academic career, and (4) changing career goal. From T3 (third year of residency) to T5, respondents in Cluster 1-3 were rather stable in terms of their career path aspirations, while those assigned to Cluster 4 showed a high fluctuation in their career plans. Physicians in Cluster 1 showed high values in extraprofessional concerns and often consider part-time work. Cluster 2 and 3 were characterised by high instrumentality, intrinsic and extrinsic career motivation, career orientation and high career success. No cluster differences were seen in career satisfaction. In Cluster 1 and 4, females were overrepresented. Trainees should be supported to stay on the career path that best suits his/her personal and

  9. Path diversity improves the identification of influential spreaders

    Science.gov (United States)

    Chen, Duan-Bing; Xiao, Rui; Zeng, An; Zhang, Yi-Cheng

    2013-12-01

    Identifying influential spreaders in complex networks is a crucial problem which relates to wide applications. Many methods based on the global information such as K-shell and PageRank have been applied to rank spreaders. However, most of the related previous works overwhelmingly focus on the number of paths for propagation, while whether the paths are diverse enough is usually overlooked. Generally, the spreading ability of a node might not be strong if its propagation depends on one or two paths while the other paths are dead ends. In this letter, we introduced the concept of path diversity and find that it can largely improve the ranking accuracy. We further propose a local method combining the information of path number and path diversity to identify influential nodes in complex networks. This method is shown to outperform many well-known methods in both undirected and directed networks. Moreover, the efficiency of our method makes it possible to apply it to very large systems.

  10. [Which route leads from chronic back pain to depression? A path analysis on direct and indirect effects using the cognitive mediators catastrophizing and helplessness/hopelessness in a general population sample].

    Science.gov (United States)

    Fahland, R A; Kohlmann, T; Hasenbring, M; Feng, Y-S; Schmidt, C O

    2012-12-01

    Chronic pain and depression are highly comorbid; however, the longitudinal link is only partially understood. This study examined direct and indirect effects of chronic back pain on depression using path analysis in a general population sample, focussing on cognitive mediator variables. Analyses are based on 413 participants (aged 18-75 years) in a population-based postal survey on back pain who reported chronic back pain at baseline. Follow-up data were collected after 1 year. Depression was measured with the Center for Epidemiologic Studies Depression Scale (CES-D). Fear-avoidance-beliefs (FABQ), catastrophizing and helplessness/hopelessness (KRSS) were considered as cognitive mediators. Data were analyzed using path analysis. Chronic back pain had no direct effect on depression at follow-up when controlling for cognitive mediators. A mediating effect emerged for helplessness/hopelessness but not for catastrophizing or fear-avoidance beliefs. These results support the cognitive mediation hypothesis which assumes that psychological variables mediate the association between pain and depression. The importance of helplessness/hopelessness is of relevance for the treatment of patients with chronic back pain.

  11. Electron Inelastic-Mean-Free-Path Database

    Science.gov (United States)

    SRD 71 NIST Electron Inelastic-Mean-Free-Path Database (PC database, no charge)   This database provides values of electron inelastic mean free paths (IMFPs) for use in quantitative surface analyses by AES and XPS.

  12. Modelling effects of tree population dynamics, tree throw and pit-mound formation/diffusion on microtopography over time in different forest settings

    Science.gov (United States)

    Martin, Y. E.; Johnson, E. A.; Gallaway, J.; Chaikina, O.

    2011-12-01

    Herein we conduct a followup investigation to an earlier research project in which we developed a numerical model of tree population dynamics, tree throw, and sediment transport associated with the formation of pit-mound features for Hawk Creek watershed, Canadian Rockies (Gallaway et al., 2009). We extend this earlier work by exploring the most appropriate transport relations to simulate the diffusion over time of newly-formed pit-pound features due to tree throw. We combine our earlier model with a landscape development model that can incorporate these diffusive transport relations. Using these combined models, changes in hillslope microtopography over time associated with the formation of pit-mound features and their decay will be investigated. The following ideas have motivated this particular study: (i) Rates of pit-mound degradation remain a source of almost complete speculation, as there is almost no long-term information on process rates. Therefore, we will attempt to tackle the issue of pit-mound degradation in a methodical way that can guide future field studies; (ii) The degree of visible pit-mound topography at any point in time on the landscape is a joint function of the rate of formation of new pit-mound features due to tree death/topple and their magnitude vs. the rate of decay of pit-mound features. An example of one interesting observation that arises is the following: it appears that pit-mound topography is often more pronounced in some eastern North American forests vs. field sites along the eastern slopes of the Canadian Rockies. Why is this the case? Our investigation begins by considering whether pit-mound decay might occur by linear or nonlinear diffusion. What differences might arise depending on which diffusive approach is adopted? What is the magnitude of transport rates associated with these possible forms of transport relations? We explore linear and nonlinear diffusion at varying rates and for different sizes of pit-mound pairs using a

  13. Hanford spent nuclear fuel project recommended path forward, volume III: Alternatives and path forward evaluation supporting documentation

    International Nuclear Information System (INIS)

    Fulton, J.C.

    1994-10-01

    Volume I of the Hanford Spent Nuclear Fuel Project - Recommended Path Forward constitutes an aggressive series of projects to construct and operate systems and facilities to safely retrieve, package, transport, process, and store K Basins fuel and sludge. Volume II provided a comparative evaluation of four Alternatives for the Path Forward and an evaluation for the Recommended Path Forward. Although Volume II contained extensive appendices, six supporting documents have been compiled in Volume III to provide additional background for Volume II

  14. Understanding and applying open-path optical sensing data

    Science.gov (United States)

    Virag, Peter; Kricks, Robert J.

    1999-02-01

    During the last 10 years, open-path air monitors have evolved to yield reliable and effective measurements of single and multiple compounds on a real-time basis. To many individuals within the optical remote sensing community, the attributes of open-path and its the potential uses seem unlimited. Then why has the market has been stagnant for the last few years? The reason may center on how open-path information is applied and how well the end user understands that information. We constantly try to compare open-path data to risk/health or safety levels that are based for use at a single point and for a specific averaging period often far longer than a typical open-path data point. Often this approach is perceived as putting a square peg in a round hole. This perception may be well founded, as open-path data at times may need to go through extensive data manipulation and assumptions before it can be applied. This paper will review pervious open-path monitoring programs and their success in applying the data collected. We will also look at how open-path data is being currently used, some previous pitfalls in data use, alternate methods of data interpretation, and how open-path data can be best practically applied to fit current needs.

  15. Unusual bond paths in organolithium compounds

    International Nuclear Information System (INIS)

    Bachrach, S.M.; Ritchie, J.P.

    1986-01-01

    We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

  16. Two-path plasmonic interferometer with integrated detector

    Science.gov (United States)

    Dyer, Gregory Conrad; Shaner, Eric A.; Aizin, Gregory

    2016-03-29

    An electrically tunable terahertz two-path plasmonic interferometer with an integrated detection element can down convert a terahertz field to a rectified DC signal. The integrated detector utilizes a resonant plasmonic homodyne mixing mechanism that measures the component of the plasma waves in-phase with an excitation field that functions as the local oscillator in the mixer. The plasmonic interferometer comprises two independently tuned electrical paths. The plasmonic interferometer enables a spectrometer-on-a-chip where the tuning of electrical path length plays an analogous role to that of physical path length in macroscopic Fourier transform interferometers.

  17. Optimization of educational paths for higher education

    Science.gov (United States)

    Tarasyev, Alexandr A.; Agarkov, Gavriil; Medvedev, Aleksandr

    2017-11-01

    In our research, we combine the theory of economic behavior and the methodology of increasing efficiency of the human capital to estimate the optimal educational paths. We provide an optimization model for higher education process to analyze possible educational paths for each rational individual. The preferences of each rational individual are compared to the best economically possible educational path. The main factor of the individual choice, which is formed by the formation of optimal educational path, deals with higher salaries level in the chosen economic sector after graduation. Another factor that influences on the economic profit is the reduction of educational costs or the possibility of the budget support for the student. The main outcome of this research consists in correction of the governmental policy of investment in human capital based on the results of educational paths optimal control.

  18. A moderated mediated path analysis of factors influencing student performance on a standardized high-stakes science test

    Science.gov (United States)

    Pelkey, Ramona K.

    Gender, ethnicity, family economic status, reading score, mathematics score, and number of science semesters successfully completed were examined for their contributory role to a student's science score on a high-stakes, high school exit examination. Path analysis and analysis of variance procedures were used to quantify each variable's influence on science score. Gender, ethnicity, and family economic status were found to be moderators while reading proved to mediate within the model. The path model was created using a calibration sample and cross-validated using a hold-out validation sample. Bootstrapping was used to verify the goodness of fit of the model. A predictive equation explained 66% (R2 = .66) of the variance in observed TAKS science score.

  19. Path operator algebras in conformal quantum field theories

    International Nuclear Information System (INIS)

    Roesgen, M.

    2000-10-01

    Two different kinds of path algebras and methods from noncommutative geometry are applied to conformal field theory: Fusion rings and modular invariants of extended chiral algebras are analyzed in terms of essential paths which are a path description of intertwiners. As an example, the ADE classification of modular invariants for minimal models is reproduced. The analysis of two-step extensions is included. Path algebras based on a path space interpretation of character identities can be applied to the analysis of fusion rings as well. In particular, factorization properties of character identities and therefore of the corresponding path spaces are - by means of K-theory - related to the factorization of the fusion ring of Virasoro- and W-algebras. Examples from nonsupersymmetric as well as N=2 supersymmetric minimal models are discussed. (orig.)

  20. Implementation of PATHS through Dutch Municipal Health Services: A Quasi-Experiment

    Directory of Open Access Journals (Sweden)

    Ferry X. Goossens

    2012-12-01

    Full Text Available Only a limited number of effectiveness studies have been performed to study the benefits of efficacious behavior problems prevention programs for children when implemented through national health service systems. This study uses a quasi-experimental design to test the effectiveness of the school-based PATHS prevention program (Providing Alternative THinking Strategies when implemented through Dutch municipal health services by health promotion professionals. A sample of 1,294 children was followed for two years: 674 children attending nine schools providing PATHS and 620 children in nine comparison schools. We hypothesized finding an intervention effect of PATHS in terms of a significant reduction in teacher- and student-rated externalizing and internalizing problem behaviors, and a significant improvement in teacher-, student-, and peer-rated social skills and emotional skills. In fact, the results show low levels of programimplementation and no intervention effects on problem behavior or social and emotional skills, suggesting that it is hard to reproduce positive intervention effects where an efficacious social-emotional prevention program is implemented through a national health service. More research is needed on the specific conditions required to implement efficacious programs effectively.

  1. Beyond Tree Throw: Wind, Water, Rock and the Mechanics of Tree-Driven Bedrock Physical Weathering

    Science.gov (United States)

    Marshall, J. A.; Anderson, R. S.; Dawson, T. E.; Dietrich, W. E.; Minear, J. T.

    2017-12-01

    Tree throw is often invoked as the dominant process in converting bedrock to soil and thus helping to build the Critical Zone (CZ). In addition, observations of tree roots lifting sidewalk slabs, occupying cracks, and prying slabs of rock from cliff faces have led to a general belief in the power of plant growth forces. These common observations have led to conceptual models with trees at the center of the soil genesis process. This is despite the observation that tree throw is rare in many forested settings, and a dearth of field measurements that quantify the magnitude of growth forces. While few trees blow down, every tree grows roots, inserting many tens of percent of its mass below ground. Yet we lack data quantifying the role of trees in both damaging bedrock and detaching it (and thus producing soil). By combing force measurements at the tree-bedrock interface with precipitation, solar radiation, wind speed, and wind-driven tree sway data we quantified the magnitude and frequency of tree-driven soil-production mechanisms from two contrasting climatic and lithologic regimes (Boulder and Eel Creek CZ Observatories). Preliminary data suggests that in settings with relatively thin soils, trees can damage and detach rock due to diurnal fluctuations, wind response and rainfall events. Surprisingly, our data suggests that forces from roots and trunks growing against bedrock are insufficient to pry rock apart or damage bedrock although much more work is needed in this area. The frequency, magnitude and style of wind-driven tree forces at the bedrock interface varies considerably from one to another species. This suggests that tree properties such as mass, elasticity, stiffness and branch structure determine whether trees respond to gusts big or small, move at the same frequency as large wind gusts, or are able to self-dampen near-ground sway response to extended wind forces. Our measurements of precipitation-driven and daily fluctuations in root pressures exerted on

  2. Computing the optimal path in stochastic dynamical systems

    International Nuclear Information System (INIS)

    Bauver, Martha; Forgoston, Eric; Billings, Lora

    2016-01-01

    In stochastic systems, one is often interested in finding the optimal path that maximizes the probability of escape from a metastable state or of switching between metastable states. Even for simple systems, it may be impossible to find an analytic form of the optimal path, and in high-dimensional systems, this is almost always the case. In this article, we formulate a constructive methodology that is used to compute the optimal path numerically. The method utilizes finite-time Lyapunov exponents, statistical selection criteria, and a Newton-based iterative minimizing scheme. The method is applied to four examples. The first example is a two-dimensional system that describes a single population with internal noise. This model has an analytical solution for the optimal path. The numerical solution found using our computational method agrees well with the analytical result. The second example is a more complicated four-dimensional system where our numerical method must be used to find the optimal path. The third example, although a seemingly simple two-dimensional system, demonstrates the success of our method in finding the optimal path where other numerical methods are known to fail. In the fourth example, the optimal path lies in six-dimensional space and demonstrates the power of our method in computing paths in higher-dimensional spaces.

  3. Path lumping: An efficient algorithm to identify metastable path channels for conformational dynamics of multi-body systems

    Science.gov (United States)

    Meng, Luming; Sheong, Fu Kit; Zeng, Xiangze; Zhu, Lizhe; Huang, Xuhui

    2017-07-01

    Constructing Markov state models from large-scale molecular dynamics simulation trajectories is a promising approach to dissect the kinetic mechanisms of complex chemical and biological processes. Combined with transition path theory, Markov state models can be applied to identify all pathways connecting any conformational states of interest. However, the identified pathways can be too complex to comprehend, especially for multi-body processes where numerous parallel pathways with comparable flux probability often coexist. Here, we have developed a path lumping method to group these parallel pathways into metastable path channels for analysis. We define the similarity between two pathways as the intercrossing flux between them and then apply the spectral clustering algorithm to lump these pathways into groups. We demonstrate the power of our method by applying it to two systems: a 2D-potential consisting of four metastable energy channels and the hydrophobic collapse process of two hydrophobic molecules. In both cases, our algorithm successfully reveals the metastable path channels. We expect this path lumping algorithm to be a promising tool for revealing unprecedented insights into the kinetic mechanisms of complex multi-body processes.

  4. Moments of inertia and the shapes of Brownian paths

    International Nuclear Information System (INIS)

    Fougere, F.; Desbois, J.

    1993-01-01

    The joint probability law of the principal moments of inertia of Brownian paths (open or closed) is computed, using constrained path integrals and Random Matrix Theory. The case of two-dimensional paths is discussed in detail. In particular, it is shown that the ratio of the average values of the largest and smallest moments is equal to 4.99 (open paths) and 3.07 (closed paths). Results of numerical simulations are also presented, which include investigation of the relationships between the moments of inertia and the arithmetic area enclosed by a path. (authors) 28 refs., 2 figs

  5. Quick start users guide for the PATH/AWARE decision support system.

    Energy Technology Data Exchange (ETDEWEB)

    Knowlton, Robert G.; Melton, Brad J; Einfeld, Wayne; Tucker, Mark D; Franco, David Oliver; Yang, Lynn I.

    2013-06-01

    The Prioritization Analysis Tool for All-Hazards/Analyzer for Wide Area Restoration Effectiveness (PATH/AWARE) software system, developed by Sandia National Laboratories, is a comprehensive decision support tool designed to analyze situational awareness, as well as response and recovery actions, following a wide-area release of chemical, biological or radiological materials. The system provides capability to prioritize critical infrastructure assets and services for restoration. It also provides a capability to assess resource needs (e.g., number of sampling teams, laboratory capacity, decontamination units, etc.), timelines for consequence management activities, and costs. PATH/AWARE is a very comprehensive tool set with a considerable amount of database information managed through a Microsoft SQL (Structured Query Language) database engine, a Geographical Information System (GIS) engine that provides comprehensive mapping capabilities, as well as comprehensive decision logic to carry out the functional aspects of the tool set. This document covers the basic installation and operation of the PATH/AWARE tool in order to give the user enough information to start using the tool. A companion users manual is under development with greater specificity of the PATH/AWARE functionality.

  6. Path Integrals in Quantum Mechanics

    International Nuclear Information System (INIS)

    Louko, J

    2005-01-01

    Jean Zinn-Justin's textbook Path Integrals in Quantum Mechanics aims to familiarize the reader with the path integral as a calculational tool in quantum mechanics and field theory. The emphasis is on quantum statistical mechanics, starting with the partition function Tr exp(-β H) and proceeding through the diffusion equation to barrier penetration problems and their semiclassical limit. The 'real time' path integral is defined via analytic continuation and used for the path-integral representation of the nonrelativistic S-matrix and its perturbative expansion. Holomorphic and Grassmannian path integrals are introduced and applied to nonrelativistic quantum field theory. There is also a brief discussion of path integrals in phase space. The introduction includes a brief historical review of path integrals, supported by a bibliography with some 40 entries. As emphasized in the introduction, mathematical rigour is not a central issue in the book. This allows the text to present the calculational techniques in a very readable manner: much of the text consists of worked-out examples, such as the quartic anharmonic oscillator in the barrier penetration chapter. At the end of each chapter there are exercises, some of which are of elementary coursework type, but the majority are more in the style of extended examples. Most of the exercises indeed include the solution or a sketch thereof. The book assumes minimal previous knowledge of quantum mechanics, and some basic quantum mechanical notation is collected in an appendix. The material has a large overlap with selected chapters in the author's thousand-page textbook Quantum Field Theory and Critical Phenomena (2002 Oxford: Clarendon). The stand-alone scope of the present work has, however, allowed a more focussed organization of this material, especially in the chapters on, respectively, holomorphic and Grassmannian path integrals. In my view the book accomplishes its aim admirably and is eminently usable as a textbook

  7. 76 FR 17064 - Shared Use Path Accessibility Guidelines

    Science.gov (United States)

    2011-03-28

    ...] RIN 3014-AA41 Shared Use Path Accessibility Guidelines AGENCY: Architectural and Transportation... (ANPRM) to develop accessibility guidelines for shared use paths. Shared use paths are designed for both... users. The guidelines will include technical provisions for making newly constructed and altered shared...

  8. A focussed dynamic path finding algorithm with constraints

    CSIR Research Space (South Africa)

    Leenen, L

    2013-11-01

    Full Text Available heuristic to focus the search for an optimal path. Existing approaches to solving path planning problems tend to combine path costs with various other criteria such as obstacle avoidance in the objective function which is being optimised. The authors...

  9. Path probability of stochastic motion: A functional approach

    Science.gov (United States)

    Hattori, Masayuki; Abe, Sumiyoshi

    2016-06-01

    The path probability of a particle undergoing stochastic motion is studied by the use of functional technique, and the general formula is derived for the path probability distribution functional. The probability of finding paths inside a tube/band, the center of which is stipulated by a given path, is analytically evaluated in a way analogous to continuous measurements in quantum mechanics. Then, the formalism developed here is applied to the stochastic dynamics of stock price in finance.

  10. Land-mobile satellite excess path loss measurements

    Science.gov (United States)

    Hess, G. C.

    1980-05-01

    An experiment conducted with the ATS-6 satellite to determine the additional path loss over free-space loss experienced by land-mobile communication links is described. This excess path loss is measured as a function of 1) local environment, 2) vehicle heading, 3) link frequency, 4) satellite elevation angle, and 5) street side. A statistical description of excess loss developed from the data shows that the first two parameters dominate. Excess path loss on the order of 25 dB is typical in urban situations, but decreases to under 10 dB in suburban/rural areas. Spaced antenna selection diversity is found to provide only a slight decrease (4 dB, typically) in the urban excess path loss observed. Level crossing rates are depressed in satellite links relative to those of Rayleigh-faded terrestrial links, but increases in average fade durations tend to offset that advantage. The measurements show that the excess path loss difference between 860-MHz links and 1550-MHz links is generally negligible.

  11. Perfect discretization of reparametrization invariant path integrals

    International Nuclear Information System (INIS)

    Bahr, Benjamin; Dittrich, Bianca; Steinhaus, Sebastian

    2011-01-01

    To obtain a well-defined path integral one often employs discretizations. In the case of gravity and reparametrization-invariant systems, the latter of which we consider here as a toy example, discretizations generically break diffeomorphism and reparametrization symmetry, respectively. This has severe implications, as these symmetries determine the dynamics of the corresponding system. Indeed we will show that a discretized path integral with reparametrization-invariance is necessarily also discretization independent and therefore uniquely determined by the corresponding continuum quantum mechanical propagator. We use this insight to develop an iterative method for constructing such a discretized path integral, akin to a Wilsonian RG flow. This allows us to address the problem of discretization ambiguities and of an anomaly-free path integral measure for such systems. The latter is needed to obtain a path integral, that can act as a projector onto the physical states, satisfying the quantum constraints. We will comment on implications for discrete quantum gravity models, such as spin foams.

  12. Perfect discretization of reparametrization invariant path integrals

    Science.gov (United States)

    Bahr, Benjamin; Dittrich, Bianca; Steinhaus, Sebastian

    2011-05-01

    To obtain a well-defined path integral one often employs discretizations. In the case of gravity and reparametrization-invariant systems, the latter of which we consider here as a toy example, discretizations generically break diffeomorphism and reparametrization symmetry, respectively. This has severe implications, as these symmetries determine the dynamics of the corresponding system. Indeed we will show that a discretized path integral with reparametrization-invariance is necessarily also discretization independent and therefore uniquely determined by the corresponding continuum quantum mechanical propagator. We use this insight to develop an iterative method for constructing such a discretized path integral, akin to a Wilsonian RG flow. This allows us to address the problem of discretization ambiguities and of an anomaly-free path integral measure for such systems. The latter is needed to obtain a path integral, that can act as a projector onto the physical states, satisfying the quantum constraints. We will comment on implications for discrete quantum gravity models, such as spin foams.

  13. Path integral for relativistic particle theory

    International Nuclear Information System (INIS)

    Fradkin, E.S.; Gitman, D.M.; Shvartsman, Sh.M.

    1990-06-01

    An action for a relativistic spinning particle interacting with external electromagnetic field is considered in reparametrization and local supergauge invariant form. It is shown that various path integral representations derived for the causal Green function correspond to the different forms of the relativistic particle action. The analogy of the path integral derived with the Lagrangian path integral of the field theory is discussed. It is shown that to obtain the causal propagator, the integration over the null mode of the Lagrangian multiplier corresponding to the reparametrization invariance, has to be performed in the (0,+infinity) limits. (author). 23 refs

  14. Positroids Induced by Rational Dyck Paths

    OpenAIRE

    Gotti, Felix

    2017-01-01

    A rational Dyck path of type $(m,d)$ is an increasing unit-step lattice path from $(0,0)$ to $(m,d) \\in \\mathbb{Z}^2$ that never goes above the diagonal line $y = (d/m)x$. On the other hand, a positroid of rank $d$ on the ground set $[d+m]$ is a special type of matroid coming from the totally nonnegative Grassmannian. In this paper we describe how to naturally assign a rank $d$ positroid on the ground set $[d+m]$, which we name rational Dyck positroid, to each rational Dyck path of type $(m,d...

  15. Realizing spaces as path-component spaces

    OpenAIRE

    Banakh, Taras; Brazas, Jeremy

    2018-01-01

    The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

  16. Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?

    Science.gov (United States)

    Penney, Mark D.; Enshan Koh, Dax; Spekkens, Robert W.

    2017-07-01

    It is straightforward to compute the transition amplitudes of a quantum circuit using the sum-over-paths methodology when the gates in the circuit are balanced, where a balanced gate is one for which all non-zero transition amplitudes are of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits.

  17. Purely geometric path integral for spin-foams

    International Nuclear Information System (INIS)

    Shirazi, Atousa Chaharsough; Engle, Jonathan

    2014-01-01

    Spin-foams are a proposal for defining the dynamics of loop quantum gravity via path integral. In order for a path integral to be at least formally equivalent to the corresponding canonical quantization, at each point in the space of histories it is important that the integrand have not only the correct phase—a topic of recent focus in spin-foams—but also the correct modulus, usually referred to as the measure factor. The correct measure factor descends from the Liouville measure on the reduced phase space, and its calculation is a task of canonical analysis. The covariant formulation of gravity from which spin-foams are derived is the Plebanski–Holst formulation, in which the basic variables are a Lorentz connection and a Lorentz-algebra valued 2-form, called the Plebanski 2-form. However, in the final spin-foam sum, one usually sums over only spins and intertwiners, which label eigenstates of the Plebanski 2-form alone. The spin-foam sum is therefore a discretized version of a Plebanski–Holst path integral in which only the Plebanski 2-form appears, and in which the connection degrees of freedom have been integrated out. We call this a purely geometric Plebanski–Holst path integral. In prior work in which one of the authors was involved, the measure factor for the Plebanski–Holst path integral with both connection and 2-form variables was calculated. Before one discretizes this measure and incorporates it into a spin-foam sum, however, one must integrate out the connection in order to obtain the purely geometric version of the path integral. To calculate this purely geometric path integral is the principal task of the present paper, and it is done in two independent ways. Background independence of the resulting path integral is discussed in the final section, and gauge-fixing is discussed in appendix B. (paper)

  18. Acquisition Path Analysis as a Collaborative Activity

    International Nuclear Information System (INIS)

    Nakao, A.; Grundule, R.; Gushchyn, K.; El Gebaly, A.; Higgy, R.; Tsvetkov, I.; Mandl, W.

    2015-01-01

    In the International Atomic Energy Agency, acquisition path analysis (APA) is indispensable to safeguards implementation. It is an integral part of both State evaluation process and the development of State level safeguards approaches, all performed through ongoing collaborative analysis of all available safeguards relevant information by State evaluation groups (SEG) with participation of other contributors, as required. To perform comprehensive State evaluation, to develop and revise State-level safeguards approaches, and to prepare annual implementation plans, the SEG in its collaborative analysis follows accepted safeguards methodology and guidance. In particular, the guide ''Performing Acquisition Path Analysis for the Development of a State-level Safeguards Approach for a State with a CSA'' is used. This guide identifies four major steps of the APA process: 1. Consolidating information about the State's past, present and planned nuclear fuel cycle-related capabilities and infrastructure; 2. Identifying and visually presenting technically plausible acquisition paths for the State; 3. Assessing acquisition path steps (State's technical capabilities and possible actions) along the identified acquisition paths; and 4. Assessing the time needed to accomplish each identified technically plausible acquisition path for the State. The paper reports on SEG members' and other contributors' experience with APA when following the above steps, including the identification of plausible acquisition pathways, estimation of time frames for all identified steps and determination of the time needed to accomplish each acquisition path. The difficulties that the SEG encountered during the process of performing the APA are also addressed. Feedback in the form of practical suggestions for improving the clarity of the acquisition path step assessment forms and a proposal for software support are also included. (author)

  19. Adaptive Sampling based 3D Profile Measuring Method for Free-Form Surface

    Science.gov (United States)

    Duan, Xianyin; Zou, Yu; Gao, Qiang; Peng, Fangyu; Zhou, Min; Jiang, Guozhang

    2018-03-01

    In order to solve the problem of adaptability and scanning efficiency of the current surface profile detection device, a high precision and high efficiency detection approach is proposed for surface contour of free-form surface parts based on self- adaptability. The contact mechanical probe and the non-contact laser probe are synthetically integrated according to the sampling approach of adaptive front-end path detection. First, the front-end path is measured by the non-contact laser probe, and the detection path is planned by the internal algorithm of the measuring instrument. Then a reasonable measurement sampling is completed according to the planned path by the contact mechanical probe. The detection approach can effectively improve the measurement efficiency of the free-form surface contours and can simultaneously detect the surface contours of unknown free-form surfaces with different curvatures and even different rate of curvature. The detection approach proposed in this paper also has important reference value for free-form surface contour detection.

  20. Prediction of crack paths in WC-Co alloys

    International Nuclear Information System (INIS)

    Spiegler, R.; Fischmeister, H.F.

    1992-01-01

    This paper reports on a crack propagating through the WC-o microstructure which has to choose between paths along the binder/carbide interface and paths across binder regions. The latter paths are selected when the crack enters a binder region at a large angle from the nearest carbide interface, while the interface paths are preferred by cracks entering at a small angle. A critical angle can be defined for the switch from one type of crack path to the other. Empirical data for the area fractions of the two crack paths in widely different WC-Co alloys can be accounted for by a single critical angle, var-phi c = 25 degrees. Finite element analysis of the stress field in a region of binder enclosed between carbide grains shows that the preferred site for the growth of stress-induced microvoids will move from the carbide grain flanks to the interior of the binder region when the entry angle of the crack exceeds 24 degrees. Thus the observation of a critical angle deciding the crack path is verified by the stress field analysis and given a physical explanation in terms of the most likely site for microvoid formation

  1. Diferencias en la condición física y en el lanzamiento entre jugadores de balonmano de elite y amateur. [Differences in physical fitness and throwing velocity between elite and amateur handball players

    Directory of Open Access Journals (Sweden)

    Esteban Gorostiaga

    2009-12-01

    Full Text Available Resumen Para comparar la condición física y la velocidad de lanzamiento entre dos equipos de diferente nivel, 15 jugadores de elite (EM y 15 jugadores aficionados (AM de balonmano participaron en este estudio. Los sujetos fueron medidos en antropometría, 1RM en press de banca (BP, potencia muscular en BP y en media-sentadilla (HS, salto, carrera de máxima velocidad y resistencia aeróbica, y velocidad de lanzamiento. EM mostró mayor masa corporal, FFM y BMI, así como mayores valores de fuerza máxima absoluta, potencia muscular y velocidad de balón que AM. En ambos grupos se encontró correlaciones entre la velocidad de lanzamiento de 7m y la velocidad al 30% de 1RMBP. En EM, pero no en AM, se encontró correlación entre la velocidad de lanzamiento con 3 pasos en apoyo y la velocidad al 30% de 1RMBP, así como con la potencia al 100% de BMHS. Estos resultados sugieren que el desarrollo de fuerza máxima absoluta, y potencia muscular con cargas relativamente ligeras es importante para el éxito en balonmano. Palabras clave: velocidad de lanzamiento, diferentes niveles de jugadores de balonmano, potencia muscular y parámetros físicos.   Abstract To determine physical fitness and throwing velocity differences between different levels, 15 elite (EM and 15 amateur (AM male handball players were compared in this study. The subjects were tested in anthropometry, one 1RMBP, muscle power output in bench-press and half-squat, jump, sprint, endurance and throwing velocity. EM showed higher body mass, FFM and BMI, greater values in maximal absolute strength and muscle power and higher ball velocity than AM. Both showed relationships between 7m throwing velocity and velocity at 30% of 1RMBP. But only EM showed correlations between velocity at 30% of 1RMBP and power at 100% of BMHS with 3- steps running throwing velocity. The results suggest developing maximal absolute strength, and muscle power with relative light loads is important to success in

  2. Cellular scanning strategy for selective laser melting: Generating reliable, optimized scanning paths and processing parameters

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Hattel, Jesper Henri

    2015-01-01

    method based uncertainty and reliability analysis. The reliability of the scanning paths are established using cumulative probability distribution functions for process output criteria such as sample density, thermal homogeneity, etc. A customized genetic algorithm is used along with the simulation model...

  3. Quantum cosmology based on discrete Feynman paths

    International Nuclear Information System (INIS)

    Chew, Geoffrey F.

    2002-01-01

    Although the rules for interpreting local quantum theory imply discretization of process, Lorentz covariance is usually regarded as precluding time quantization. Nevertheless a time-discretized quantum representation of redshifting spatially-homogeneous universe may be based on discrete-step Feynman paths carrying causal Lorentz-invariant action--paths that not only propagate the wave function but provide a phenomenologically-promising elementary-particle Hilbert-space basis. In a model under development, local path steps are at Planck scale while, at a much larger ''wave-function scale'', global steps separate successive wave-functions. Wave-function spacetime is but a tiny fraction of path spacetime. Electromagnetic and gravitational actions are ''at a distance'' in Wheeler-Feynman sense while strong (color) and weak (isospin) actions, as well as action of particle motion, are ''local'' in a sense paralleling the action of local field theory. ''Nonmaterial'' path segments and ''trivial events'' collaborate to define energy and gravity. Photons coupled to conserved electric charge enjoy privileged model status among elementary fermions and vector bosons. Although real path parameters provide no immediate meaning for ''measurement'', the phase of the complex wave function allows significance for ''information'' accumulated through ''gentle'' electromagnetic events involving charged matter and ''soft'' photons. Through its soft-photon content the wave function is an ''information reservoir''

  4. Path dependence and creation

    DEFF Research Database (Denmark)

    Garud, Raghu; Karnøe, Peter

    This edited volume stems from a conference held in Copenhagen that the authors ran in August of 1997. The authors, aware of the recent work in evolutionary theory and the science of chaos and complexity, challenge the sometimes deterministic flavour of this work. They are interested in uncovering...... the place of agency in these theories that take history so seriously. In the end, they are as interested in path creation and destruction as they are in path dependence. This book is compiled of both theoretical and empirical writing. It shows relatively well-known industries such as the automobile...

  5. Strain path and work-hardening behavior of brass

    International Nuclear Information System (INIS)

    Sakharova, N.A.; Fernandes, J.V.; Vieira, M.F.

    2009-01-01

    Plastic straining in metal forming usually includes changes of strain path, which are frequently not taken into account in the analysis of forming processes. Moreover, strain path change can significantly affect the mechanical behavior and microstructural evolution of the material. For this reason, a combination of several simple loading test sequences is an effective way to investigate the dislocation microstructure of sheet metals under such forming conditions. Pure tension and rolling strain paths and rolling-tension strain path sequences were performed on brass sheets. A study of mechanical behavior and microstructural evolution during the simple and the complex strain paths was carried out, within a wide range of strain values. The appearance and development of deformation twinning was evident. It was shown that strain path change promotes the onset of premature twinning. The work-hardening behavior is discussed in terms of the twinning and dislocation microstructure evolution, as revealed by transmission electron microscopy

  6. Spatial connectivity in a highly heterogeneous aquifer: From cores to preferential flow paths

    Science.gov (United States)

    Bianchi, M.; Zheng, C.; Wilson, C.; Tick, G.R.; Liu, Gaisheng; Gorelick, S.M.

    2011-01-01

    This study investigates connectivity in a small portion of the extremely heterogeneous aquifer at the Macrodispersion Experiment (MADE) site in Columbus, Mississippi. A total of 19 fully penetrating soil cores were collected from a rectangular grid of 4 m by 4 m. Detailed grain size analysis was performed on 5 cm segments of each core, yielding 1740 hydraulic conductivity (K) estimates. Three different geostatistical simulation methods were used to generate 3-D conditional realizations of the K field for the sampled block. Particle tracking calculations showed that the fastest particles, as represented by the first 5% to arrive, converge along preferential flow paths and exit the model domain within preferred areas. These 5% fastest flow paths accounted for about 40% of the flow. The distribution of preferential flow paths and particle exit locations is clearly influenced by the occurrence of clusters formed by interconnected cells with K equal to or greater than the 0.9 decile of the data distribution (10% of the volume). The fraction of particle paths within the high-K clusters ranges from 43% to 69%. In variogram-based K fields, some of the fastest paths are through media with lower K values, suggesting that transport connectivity may not require fully connected zones of relatively homogenous K. The high degree of flow and transport connectivity was confirmed by the values of two groups of connectivity indicators. In particular, the ratio between effective and geometric mean K (on average, about 2) and the ratio between the average arrival time and the arrival time of the fastest particles (on average, about 9) are consistent with flow and advective transport behavior characterized by channeling along preferential flow paths. ?? 2011 by the American Geophysical Union.

  7. Perfect discretization of path integrals

    OpenAIRE

    Steinhaus, Sebastian

    2011-01-01

    In order to obtain a well-defined path integral one often employs discretizations. In the case of General Relativity these generically break diffeomorphism symmetry, which has severe consequences since these symmetries determine the dynamics of the corresponding system. In this article we consider the path integral of reparametrization invariant systems as a toy example and present an improvement procedure for the discretized propagator. Fixed points and convergence of the procedure are discu...

  8. 28 CFR 36.403 - Alterations: Path of travel.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alterations: Path of travel. 36.403... Alterations: Path of travel. (a) General. An alteration that affects or could affect the usability of or... the maximum extent feasible, the path of travel to the altered area and the restrooms, telephones, and...

  9. Paths and cycles in colored graphs

    NARCIS (Netherlands)

    Li, Xueliang; Zhang, Shenggui; Hurink, Johann L.; Pickl, Stefan; Broersma, Haitze J.; Faigle, U.

    2001-01-01

    Let G be an (edge-)colored graph. A path (cycle) is called monochromatic if all the edges of it have the same color, and is called heterochromatic if all the edges of it have different colors. In this note, some sufficient conditions for the existence of monochromatic and heterochromatic paths and

  10. Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?

    International Nuclear Information System (INIS)

    Penney, Mark D; Koh, Dax Enshan; Spekkens, Robert W

    2017-01-01

    It is straightforward to compute the transition amplitudes of a quantum circuit using the sum-over-paths methodology when the gates in the circuit are balanced, where a balanced gate is one for which all non-zero transition amplitudes are of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits. (paper)

  11. The hybrid model for sampling multiple elastic scattering angular deflections based on Goudsmit-Saunderson theory

    Directory of Open Access Journals (Sweden)

    Wasaye Muhammad Abdul

    2017-01-01

    Full Text Available An algorithm for the Monte Carlo simulation of electron multiple elastic scattering based on the framework of SuperMC (Super Monte Carlo simulation program for nuclear and radiation process is presented. This paper describes efficient and accurate methods by which the multiple scattering angular deflections are sampled. The Goudsmit-Saunderson theory of multiple scattering has been used for sampling angular deflections. Differential cross-sections of electrons and positrons by neutral atoms have been calculated by using Dirac partial wave program ELSEPA. The Legendre coefficients are accurately computed by using the Gauss-Legendre integration method. Finally, a novel hybrid method for sampling angular distribution has been developed. The model uses efficient rejection sampling method for low energy electrons (500 mean free paths. For small path lengths, a simple, efficient and accurate analytical distribution function has been proposed. The later uses adjustable parameters determined from the fitting of Goudsmith-Saunderson angular distribution. A discussion of the sampling efficiency and accuracy of this newly developed algorithm is given. The efficiency of rejection sampling algorithm is at least 50 % for electron kinetic energies less than 500 keV and longer path lengths (>500 mean free paths. Monte Carlo Simulation results are then compared with measured angular distributions of Ross et al. The comparison shows that our results are in good agreement with experimental measurements.

  12. The formal path integral and quantum mechanics

    International Nuclear Information System (INIS)

    Johnson-Freyd, Theo

    2010-01-01

    Given an arbitrary Lagrangian function on R d and a choice of classical path, one can try to define Feynman's path integral supported near the classical path as a formal power series parameterized by 'Feynman diagrams', although these diagrams may diverge. We compute this expansion and show that it is (formally, if there are ultraviolet divergences) invariant under volume-preserving changes of coordinates. We prove that if the ultraviolet divergences cancel at each order, then our formal path integral satisfies a 'Fubini theorem' expressing the standard composition law for the time evolution operator in quantum mechanics. Moreover, we show that when the Lagrangian is inhomogeneous quadratic in velocity such that its homogeneous-quadratic part is given by a matrix with constant determinant, then the divergences cancel at each order. Thus, by 'cutting and pasting' and choosing volume-compatible local coordinates, our construction defines a Feynman-diagrammatic 'formal path integral' for the nonrelativistic quantum mechanics of a charged particle moving in a Riemannian manifold with an external electromagnetic field.

  13. Release path temperatures of shock-compressed tin from dynamic reflectance and radiance measurements

    Energy Technology Data Exchange (ETDEWEB)

    La Lone, B. M., E-mail: lalonebm@nv.doe.gov; Stevens, G. D.; Turley, W. D. [National Security Technologies, LLC, Special Technologies Laboratory, Santa Barbara, California 93111 (United States); Holtkamp, D. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Iverson, A. J. [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States); Hixson, R. S.; Veeser, L. R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)

    2013-08-14

    Dynamic reflectance and radiance measurements were conducted for tin samples shock compressed to 35 GPa and released to 15 GPa using high explosives. We determined the reflectance of the tin samples glued to lithium fluoride windows using an integrating sphere with an internal xenon flashlamp as an illumination source. The dynamic reflectance (R) was determined at near normal incidence in four spectral bands with coverage in visible and near-infrared spectra. Uncertainties in R/R{sub 0} are <2%, and uncertainties in absolute reflectance are <5%. In complementary experiments, thermal radiance from the tin/glue/lithium fluoride interface was recorded with similar shock stress and spectral coverage as the reflectance measurements. The two sets of experiments were combined to obtain the temperature history of the tin surface with an uncertainty of <2%. The stress at the interface was determined from photonic Doppler velocimetry and combined with the temperatures to obtain temperature-stress release paths for tin. We discuss the relationship between the experimental release paths and release isentropes that begin on the principal shock Hugoniot.

  14. A New Method of Global Path Planning for AGV

    Institute of Scientific and Technical Information of China (English)

    SHI En-xiu; HUANG Yu-mei

    2006-01-01

    Path planning is important in the research of a mobile robot (MR). Methods for it have been used in different applications. An automated guided vehicle(AGV), which is a kind of MR, is used in a flexible manufacturing system(FMS). Path planning for it is essential to improve the efficiency of FMS. A new method was proposed with known obstacle space FMS in this paper. FMS is described by the Augmented Pos Matrix of a Machine (APMM) and Relative Pos Matrix of Machines (RPMM), which is smaller. The optimum path can be obtained according to the probability of the path and the maximal probability path. The suggested algorithm of path planning was good performance through simulation result: simplicity, saving time and reliability.

  15. Phase-space path-integral calculation of the Wigner function

    International Nuclear Information System (INIS)

    Samson, J H

    2003-01-01

    The Wigner function W(q, p) is formulated as a phase-space path integral, whereby its sign oscillations can be seen to follow from interference between the geometrical phases of the paths. The approach has similarities to the path-centroid method in the configuration-space path integral. Paths can be classified by the midpoint of their ends; short paths where the midpoint is close to (q, p) and which lie in regions of low energy (low P function of the Hamiltonian) will dominate, and the enclosed area will determine the sign of the Wigner function. As a demonstration, the method is applied to a sequence of density matrices interpolating between a Poissonian number distribution and a number state, each member of which can be represented exactly by a discretized path integral with a finite number of vertices. Saddle-point evaluation of these integrals recovers (up to a constant factor) the WKB approximation to the Wigner function of a number state

  16. PATHS groundwater hydrologic model

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.W.; Schur, J.A.

    1980-04-01

    A preliminary evaluation capability for two-dimensional groundwater pollution problems was developed as part of the Transport Modeling Task for the Waste Isolation Safety Assessment Program (WISAP). Our approach was to use the data limitations as a guide in setting the level of modeling detail. PATHS Groundwater Hydrologic Model is the first level (simplest) idealized hybrid analytical/numerical model for two-dimensional, saturated groundwater flow and single component transport; homogeneous geology. This document consists of the description of the PATHS groundwater hydrologic model. The preliminary evaluation capability prepared for WISAP, including the enhancements that were made because of the authors' experience using the earlier capability is described. Appendixes A through D supplement the report as follows: complete derivations of the background equations are provided in Appendix A. Appendix B is a comprehensive set of instructions for users of PATHS. It is written for users who have little or no experience with computers. Appendix C is for the programmer. It contains information on how input parameters are passed between programs in the system. It also contains program listings and test case listing. Appendix D is a definition of terms.

  17. Modeling and Solving the Train Pathing Problem

    Directory of Open Access Journals (Sweden)

    Chuen-Yih Chen

    2009-04-01

    Full Text Available In a railroad system, train pathing is concerned with the assignment of trains to links and tracks, and train timetabling allocates time slots to trains. In this paper, we present an optimization heuristic to solve the train pathing and timetabling problem. This heuristic allows the dwell time of trains in a station or link to be dependent on the assigned tracks. It also allows the minimum clearance time between the trains to depend on their relative status. The heuristic generates a number of alternative paths for each train service in the initialization phase. Then it uses a neighborhood search approach to find good feasible combinations of these paths. A linear program is developed to evaluate the quality of each combination that is encountered. Numerical examples are provided.

  18. Career path determinants of Eco-Tourism and Hospitality Management university graduates

    Directory of Open Access Journals (Sweden)

    Antoneta Njeri Kariru

    2013-01-01

    Full Text Available There has been an increase in the number of hospitality management university graduates working in non hospitality organizations in Kenya. Despite this, studies have not been undertaken to investigate the factors that influence these graduates’ career decisions. The purpose of this study was thus to investigate the career path determinants of Maseno University’s hospitality management graduates. The population of study was ecotourism, hotel and institution management graduates of Maseno University working within and outside the hospitality industry. 150 respondents, from the sampling frame consisting of students who graduated between the years 2005 and 2010, were selected through snowballing. Structured questionnaires were self-administered to the respondents. Frequencies, percentages, means, factor loadings and regressions were computed and presented using SPSS version 17. The study revealed that the graduates’ major career path determinants are unpredictable events, career satisfaction levels, chance and permanency of career.

  19. Special cases of the quadratic shortest path problem

    NARCIS (Netherlands)

    Sotirov, Renata; Hu, Hao

    2017-01-01

    The quadratic shortest path problem (QSPP) is the problem of finding a path with prespecified start vertex s and end vertex t in a digraph such that the sum of weights of arcs and the sum of interaction costs over all pairs of arcs on the path is minimized. We first consider a variant of the QSPP

  20. Differential neural network configuration during human path integration

    Science.gov (United States)

    Arnold, Aiden E. G. F; Burles, Ford; Bray, Signe; Levy, Richard M.; Iaria, Giuseppe

    2014-01-01

    Path integration is a fundamental skill for navigation in both humans and animals. Despite recent advances in unraveling the neural basis of path integration in animal models, relatively little is known about how path integration operates at a neural level in humans. Previous attempts to characterize the neural mechanisms used by humans to visually path integrate have suggested a central role of the hippocampus in allowing accurate performance, broadly resembling results from animal data. However, in recent years both the central role of the hippocampus and the perspective that animals and humans share similar neural mechanisms for path integration has come into question. The present study uses a data driven analysis to investigate the neural systems engaged during visual path integration in humans, allowing for an unbiased estimate of neural activity across the entire brain. Our results suggest that humans employ common task control, attention and spatial working memory systems across a frontoparietal network during path integration. However, individuals differed in how these systems are configured into functional networks. High performing individuals were found to more broadly express spatial working memory systems in prefrontal cortex, while low performing individuals engaged an allocentric memory system based primarily in the medial occipito-temporal region. These findings suggest that visual path integration in humans over short distances can operate through a spatial working memory system engaging primarily the prefrontal cortex and that the differential configuration of memory systems recruited by task control networks may help explain individual biases in spatial learning strategies. PMID:24808849

  1. A Key Event Path Analysis Approach for Integrated Systems

    Directory of Open Access Journals (Sweden)

    Jingjing Liao

    2012-01-01

    Full Text Available By studying the key event paths of probabilistic event structure graphs (PESGs, a key event path analysis approach for integrated system models is proposed. According to translation rules concluded from integrated system architecture descriptions, the corresponding PESGs are constructed from the colored Petri Net (CPN models. Then the definitions of cycle event paths, sequence event paths, and key event paths are given. Whereafter based on the statistic results after the simulation of CPN models, key event paths are found out by the sensitive analysis approach. This approach focuses on the logic structures of CPN models, which is reliable and could be the basis of structured analysis for discrete event systems. An example of radar model is given to characterize the application of this approach, and the results are worthy of trust.

  2. Comparison of tool feed influence in CNC polishing between a novel circular-random path and other pseudo-random paths.

    Science.gov (United States)

    Takizawa, Ken; Beaucamp, Anthony

    2017-09-18

    A new category of circular pseudo-random paths is proposed in order to suppress repetitive patterns and improve surface waviness on ultra-precision polished surfaces. Random paths in prior research had many corners, therefore deceleration of the polishing tool affected the surface waviness. The new random path can suppress velocity changes of the polishing tool and thus restrict degradation of the surface waviness, making it suitable for applications with stringent mid-spatial-frequency requirements such as photomask blanks for EUV lithography.

  3. Evaluation of Calcine Disposition Path Forward

    International Nuclear Information System (INIS)

    Birrer, S.A.; Heiser, M.B.

    2003-01-01

    This document describes an evaluation of the baseline and two alternative disposition paths for the final disposition of the calcine wastes stored at the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory. The pathways are evaluated against a prescribed set of criteria and a recommendation is made for the path forward

  4. Path probabilities of continuous time random walks

    International Nuclear Information System (INIS)

    Eule, Stephan; Friedrich, Rudolf

    2014-01-01

    Employing the path integral formulation of a broad class of anomalous diffusion processes, we derive the exact relations for the path probability densities of these processes. In particular, we obtain a closed analytical solution for the path probability distribution of a Continuous Time Random Walk (CTRW) process. This solution is given in terms of its waiting time distribution and short time propagator of the corresponding random walk as a solution of a Dyson equation. Applying our analytical solution we derive generalized Feynman–Kac formulae. (paper)

  5. Kinematic analysis of rugby lineout throws in the Six Nations Tournament. [Análisis cinemático de los saques de lateral en el Torneo de Rugby del Seis Naciones].

    Directory of Open Access Journals (Sweden)

    Ignacio Martín

    2018-04-01

    Full Text Available Abstract This study examines 126 successful, six- or seven-man lineouts of the 2013 Six Nations Tournament. Data were extracted from footage of the competition to calculate kinematic variables along with jumper position. Through cluster analysis, six types of throw were identified according to distance and velocity: short-fast, short-slow, medium short-fast, medium short-slow, medium long and long. Significant differences were detected in all the variables examined depending on the throw category (throw distance P<0.001; Partial eta square η2=0.932, height P=0.032; η2=0.096, flight time P<0.001; η2=0.789, starting angle P<0.001; η2=0.502, initial velocity P<0.001; η2=0.767 and jumper position P<0.001; η2=0.641. In the discriminant analysis, all variables except jumper position were able to correctly classify 100% of the throws. In addition, we differentiated the six participating teams, finding significant differences in throw height (Scotland vs England difference means d=0.32m, Ireland d=0.36m or France d=0.37m, flight time (Italy vs England d=0.34s or Ireland d=0.33s and angle (Italy vs England d=9.72º or Ireland d=8.49º and Scotland vs England d=8.27º or Ireland d=7.04º. Our findings have implications for training and team analysis (own and rival and also provide direction for future investigations. Resumen El presente estudio ha investigado 126 saques de lateral ganados con seis o siete jugadores en el alineamiento del torneo de las Seis Naciones de 2013 La observación se ha realizado a partir del estudio de los videos, por lo que los datos están extraídos en competición real. Un análisis cluster nos ha permitido establecer seis tipos de lanzamientos en función de la distancia y la velocidad: cortos-rápidos, cortos-lentos, mediocortos-rápidos, mediocortos-lentos, mediolargos y largos. Hemos encontrado diferencias significativas en todas las variables estudiadas en función de los tipos de lanzamiento (distancia del

  6. Path-integral approach to resonant electron-molecule scattering

    International Nuclear Information System (INIS)

    Winterstetter, M.; Domcke, W.

    1993-01-01

    A path-integral formulation of resonant electron-molecule scattering is developed within the framework of the projection-operator formalism of scattering theory. The formation and decay of resonances is treated in real time as a quantum-mechanical electronic-tunneling process, modified by the coupling of the electronic motion with the nuclear degrees of freedom. It is shown that the electronic continuum can be summed over in the path-integral formulation, resulting formally in the path integral for an effective two-state system with coupling to vibrations. The harmonic-oscillator approximation is adopted for the vibrational motion in the present work. Approximation methods are introduced which render the numerical evaluation of the sum over paths feasible for up to ∼10 3 elementary time slices. The theory is numerically realized for simple but nontrivial models representing the 2 Π g d-wave shape resonance in e - +N 2 collisions and the 2 Σ u + p-wave shape resonance in e - +H 2 collisions, respectively. The accuracy of the path-integral results is assessed by comparison with exact numerical reference data for these models. The essential virtue of the path-integral approach is the fact that the computational effort scales at most linearly with the number of vibrational degrees of freedom. The path-integral method is thus well suited to treat electron collisions with polyatomic molecules and molecular aggregates

  7. The influence of parenting style on academic achievement and career path

    OpenAIRE

    ZAHRA ZAHED ZAHEDANI; RITA REZAEE; ZAHRA YAZDANI; SINA BAGHERI; PARISA NABEIEI

    2016-01-01

    Introduction Several factors affect the academic performance of college students and parenting style is one significant factor. The current study has been done with the purpose of investigating the relationship between parenting styles, academic achievement and career path of students at Shiraz University of Medical Sciences.???? Methods This is a correlation study carried out at Shiraz University of Medical Sciences. Among 1600 students, 310 students were selected randomly as the sample. Bau...

  8. Multiple Smaller Missions as a Direct Pathway to Mars Sample Return

    Science.gov (United States)

    Niles, P. B.; Draper, D. S.; Evans, C. A.; Gibson, E. K.; Graham, L. D.; Jones, J. H.; Lederer, S. M.; Ming, D.; Seaman, C. H.; Archer, P. D.; hide

    2012-01-01

    Recent discoveries by the Mars Exploration Rovers, Mars Express, Mars Odyssey, and Mars Reconnaissance Orbiter spacecraft include multiple, tantalizing astrobiological targets representing both past and present environments on Mars. The most desirable path to Mars Sample Return (MSR) would be to collect and return samples from that site which provides the clearest examples of the variety of rock types considered a high priority for sample return (pristine igneous, sedimentary, and hydrothermal). Here we propose an MSR architecture in which the next steps (potentially launched in 2018) would entail a series of smaller missions, including caching, to multiple landing sites to verify the presence of high priority sample return targets through in situ analyses. This alternative architecture to one flagship-class sample caching mission to a single site would preserve a direct path to MSR as stipulated by the Planetary Decadal Survey, while permitting investigation of diverse deposit types and providing comparison of the site of returned samples to other aqueous environments on early Mars

  9. Quadcopter Path Following Control Design Using Output Feedback with Command Generator Tracker LOS Based At Square Path

    Science.gov (United States)

    Nugraha, A. T.; Agustinah, T.

    2018-01-01

    Quadcopter an unstable system, underactuated and nonlinear in quadcopter control research developments become an important focus of attention. In this study, following the path control method for position on the X and Y axis, used structure-Generator Tracker Command (CGT) is tested. Attitude control and position feedback quadcopter is compared using the optimal output. The addition of the H∞ performance optimal output feedback control is used to maintain the stability and robustness of quadcopter. Iterative numerical techniques Linear Matrix Inequality (LMI) is used to find the gain controller. The following path control problems is solved using the method of LQ regulators with output feedback. Simulations show that the control system can follow the paths that have been defined in the form of a reference signal square shape. The result of the simulation suggest that the method which used can bring the yaw angle at the expected value algorithm. Quadcopter can do automatically following path with cross track error mean X=0.5 m and Y=0.2 m.

  10. Bosonic path integral for spin-1/2 particles

    International Nuclear Information System (INIS)

    Jacobson, T.

    1989-01-01

    The 3D Dirac propagator is expressed as a path integral over curves of commuting two-component spinors. This is related to the path integral recently employed by Polyakov to demonstrate Fermi-Bose transmutation for solitons in the gauged CP 1 model with Chern-Simons term. Several difficulties concerning the latter path integral are identified and corrected from our point of view. (orig.)

  11. Forces in Motzkin paths in a wedge

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2006-01-01

    Entropic forces in models of Motzkin paths in a wedge geometry are considered as models of forces in polymers in confined geometries. A Motzkin path in the square lattice is a path from the origin to a point in the line Y = X while it never visits sites below this line, and it is constrained to give unit length steps only in the north and east directions and steps of length √2 in the north-east direction. Motzkin path models may be generalized to ensembles of NE-oriented paths above the line Y = rX, where r > 0 is an irrational number. These are paths giving east, north and north-east steps from the origin in the square lattice, and confined to the r-wedge formed by the Y-axis and the line Y = rX. The generating function g r of these paths is not known, but if r > 1, then I determine its radius of convergence to be t r = min (r-1)/r≤y≤r/(r+1) [y y (1-r(1-y)) 1-r(1-y) (r(1-y)-y) r(1-y)-y ] and if r is an element of (0, 1), then t r = 1/3. The entropic force the path exerts on the line Y rX may be computed from this. An asymptotic expression for the force for large values of r is given by F(r) = log(2r)/r 2 - (1+2log(2r))/2r 3 + O (log(2r)/r 4 ). In terms of the vertex angle α of the r-wedge, the moment of the force about the origin has leading terms F(α) log(2/α) - (α/2)(1+2log(2/α)) + O(α 2 log(2/α)) as α → 0 + and F(α) = 0 if α is element of [π/4, π/2]. Moreover, numerical integration of the force shows that the total work done by closing the wedge is 1.085 07... lattice units. An alternative ensemble of NE-oriented paths may be defined by slightly changing the generating function g r . In this model, it is possible to determine closed-form expressions for the limiting free energy and the force. The leading term in an asymptotic expansions for this force agrees with the leading term in the asymptotic expansion of the above model, and the subleading term only differs by a factor of 2

  12. An improved sampling method of complex network

    Science.gov (United States)

    Gao, Qi; Ding, Xintong; Pan, Feng; Li, Weixing

    2014-12-01

    Sampling subnet is an important topic of complex network research. Sampling methods influence the structure and characteristics of subnet. Random multiple snowball with Cohen (RMSC) process sampling which combines the advantages of random sampling and snowball sampling is proposed in this paper. It has the ability to explore global information and discover the local structure at the same time. The experiments indicate that this novel sampling method could keep the similarity between sampling subnet and original network on degree distribution, connectivity rate and average shortest path. This method is applicable to the situation where the prior knowledge about degree distribution of original network is not sufficient.

  13. A middle path for electricity options and sustainable development

    International Nuclear Information System (INIS)

    Mills, J.I.; Herring, J.S.

    1994-01-01

    In a landmark article in Foreign Affairs in October 1976, Amory Lovins presented his vision of two vastly different and seemingly irreconcilable paths that energy provision might take into the future. One path was a ''hard'' path, characterized by extensive development of large, capital-intensive centralized electrical generating facilities and their peripherals, designed with little consideration given to the matching of these facilities to the requirements of the end-use needs. The second, ''soft'' path was characterized by energy technologies that are diverse, operate on renewable energy flows, are relatively simple, less capital-intensive, and matched in scale and energy quality to end-use needs. One of the most controversial arguments in the Lovins' paper was that the ''hard'' and ''soft'' paths are culturally and institutionally antagonistic. In retrospect, it seems this argument was self-fulfilling, for the history of the energy debate throughout the developed world since the appearance of the Lovins' article has been marked by an either-or antagonism that has left little room for serious discussion of a ''middle-path.'' In this paper, we argue that ''middle-path,'' paved with elements of both the soft and hard, is especially suited for developing countries, since they do not now carry the burden of an existing and extensive ''hard path'' energy infrastructure

  14. The COLIMA experiment on aerosol retention in containment leak paths under severe nuclear accidents

    Energy Technology Data Exchange (ETDEWEB)

    Parozzi, Flavio, E-mail: flavio.parozzi@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Caracciolo, Eduardo D.J., E-mail: eduardo.caracciolo@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Journeau, Christophe, E-mail: christophe.journeau@cea.fr [CEA Cadarache (France); Piluso, Pascal, E-mail: pascal.piluso@cea.fr [CEA Cadarache (France)

    2013-08-15

    Highlights: ► Experiment investigating aerosol retention within concrete containment cracks under nuclear severe accident conditions. ► Provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. ► Prototypical aerosol particles generated with a thermite reaction and transported through the crack sample reproducing surface characteristics, temperature, pressure drop and gas leakage. ► The results indicate the significant retention due to zig-zag path. -- Abstract: CEA and RSE managed an experimental research concerning the investigation of aerosol retention within concrete containment cracks under severe accident conditions. The main experiment was carried out in November 2008 with aerosol generated from the COLIMA facility and a sample of cracked concrete with defined geometric characteristics manufactured by RSE. The facility provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. Prototypical aerosol particles were generated with a thermite reaction and transported through the crack sample, where surface characteristics, temperature, pressure drop and gas leakage were properly reproduced. The paper describes the approach adopted for the preparation of the cracked concrete sample and the dimensioning of the experimental apparatus, the test procedure and the measured parameters. The preliminary results, obtained from this single test, are also discussed in the light of the present knowledge about aerosol phenomena and the theoretical analyses of particle behaviour with the crack path.

  15. The sign problem in real-time path integral simulations: Using the cumulant action to implement multilevel blocking

    International Nuclear Information System (INIS)

    Mak, C. H.

    2009-01-01

    A practical method to tackle the sign problem in real-time path integral simulations is proposed based on the multilevel blocking idea. The formulation is made possible by using a cumulant expansion of the action, which in addition to addressing the sign problem, provides an unbiased estimator for the action from a statistically noisy sample of real-time paths. The cumulant formulation also allows the analytical gradients of the action to be computed with little extra computational effort, and it can easily be implemented in a massively parallel environment.

  16. Path integral discussion for Smorodinsky-Winternitz potentials. Pt. 1

    International Nuclear Information System (INIS)

    Grosche, C.; Pogosyan, G.S.; Sissakian, A.N.

    1994-02-01

    Path integral formulations for the Smorodinsky-Winternitz potentials in two- and three-dimensional Euclidean space are presented. We mention all coordinate systems which separate the Smorodinsky-Winternitz potentials and state the corresponding path integral formulations. Whereas in many coordinate systems an explicit path integralformulation is not possible, we list in all soluble cases the path integral evaluations explicity in terms of the propagators and the spectral expansions into the wave-functions. (orig.)

  17. Preparation and tomographic reconstruction of an arbitrary single-photon path qubit

    International Nuclear Information System (INIS)

    Baek, So-Young; Kim, Yoon-Ho

    2011-01-01

    We report methods for preparation and tomographic reconstruction of an arbitrary single-photon path qubit. The arbitrary single-photon path qubit is prepared losslessly by passing the heralded single-photon state from spontaneous parametric down-conversion through variable beam splitter. Quantum state tomography of the single-photon path qubit is implemented by introducing path-projection measurements based on the first-order single-photon quantum interference. Using the state preparation and path-projection measurements methods for the single-photon path qubit, we demonstrate preparation and complete tomographic reconstruction of the single-photon path qubit with arbitrary purity. -- Highlights: → We report methods for preparation and tomographic reconstruction of an arbitrary single-photon path qubit. → We implement path-projection measurements based on the first-order single-photon quantum interference. → We demonstrate preparation and complete tomographic reconstruction of the single-photon path qubit with arbitrary purity.

  18. Walking paths to and from a goal differ: on the role of bearing angle in the formation of human locomotion paths.

    Directory of Open Access Journals (Sweden)

    Manish Sreenivasa

    Full Text Available The path that humans take while walking to a goal is the result of a cognitive process modulated by the perception of the environment and physiological constraints. The path shape and timing implicitly embeds aspects of the architecture behind this process. Here, locomotion paths were investigated during a simple task of walking to and from a goal, by looking at the evolution of the position of the human on a horizontal (x,y plane. We found that the path while walking to a goal was not the same as that while returning from it. Forward-return paths were systematically separated by 0.5-1.9m, or about 5% of the goal distance. We show that this path separation occurs as a consequence of anticipating the desired body orientation at the goal while keeping the target in view. The magnitude of this separation was strongly influenced by the bearing angle (difference between body orientation and angle to goal and the final orientation imposed at the goal. This phenomenon highlights the impact of a trade-off between a directional perceptual apparatus-eyes in the head on the shoulders-and and physiological limitations, in the formation of human locomotion paths. Our results give an insight into the influence of environmental and perceptual variables on human locomotion and provide a basis for further mathematical study of these mechanisms.

  19. Path integral representations on the complex sphere

    International Nuclear Information System (INIS)

    Grosche, C.

    2007-08-01

    In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S 3C . The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid. (orig.)

  20. Social network analysis using k-Path centrality method

    Science.gov (United States)

    Taniarza, Natya; Adiwijaya; Maharani, Warih

    2018-03-01

    k-Path centrality is deemed as one of the effective methods to be applied in centrality measurement in which the influential node is estimated as the node that is being passed by information path frequently. Regarding this, k-Path centrality has been employed in the analysis of this paper specifically by adapting random-algorithm approach in order to: (1) determine the influential user’s ranking in a social media Twitter; and (2) ascertain the influence of parameter α in the numeration of k-Path centrality. According to the analysis, the findings showed that the method of k-Path centrality with random-algorithm approach can be used to determine user’s ranking which influences in the dissemination of information in Twitter. Furthermore, the findings also showed that parameter α influenced the duration and the ranking results: the less the α value, the longer the duration, yet the ranking results were more stable.

  1. Path Planning Method in Multi-obstacle Marine Environment

    Science.gov (United States)

    Zhang, Jinpeng; Sun, Hanxv

    2017-12-01

    In this paper, an improved algorithm for particle swarm optimization is proposed for the application of underwater robot in the complex marine environment. Not only did consider to avoid obstacles when path planning, but also considered the current direction and the size effect on the performance of the robot dynamics. The algorithm uses the trunk binary tree structure to construct the path search space and A * heuristic search method is used in the search space to find a evaluation standard path. Then the particle swarm algorithm to optimize the path by adjusting evaluation function, which makes the underwater robot in the current navigation easier to control, and consume less energy.

  2. Lifetime and Path Length of the Virtual Particle

    International Nuclear Information System (INIS)

    Lyuboshitz, V.L.; Lyuboshitz, V.V.

    2005-01-01

    The concepts of the lifetime and path length of a virtual particle are introduced. It is shown that, near the mass surface of the real particle, these quantities constitute a 4-vector. At very high energies, the virtual particle can propagate over considerable (even macroscopic) distances. The formulas for the lifetime and path length of an ultrarelativistic virtual electron in the process of bremsstrahlung in the Coulomb field of a nucleus are obtained. The lifetime and path length of the virtual photon at its conversion into an electron-positron pair are discussed. The connection between the path length of the virtual particle and the coherence length (formation length) is analyzed

  3. Feasible Path Generation Using Bezier Curves for Car-Like Vehicle

    Science.gov (United States)

    Latip, Nor Badariyah Abdul; Omar, Rosli

    2017-08-01

    When planning a collision-free path for an autonomous vehicle, the main criteria that have to be considered are the shortest distance, lower computation time and completeness, i.e. a path can be found if one exists. Besides that, a feasible path for the autonomous vehicle is also crucial to guarantee that the vehicle can reach the target destination considering its kinematic constraints such as non-holonomic and minimum turning radius. In order to address these constraints, Bezier curves is applied. In this paper, Bezier curves are modeled and simulated using Matlab software and the feasibility of the resulting path is analyzed. Bezier curve is derived from a piece-wise linear pre-planned path. It is found that the Bezier curves has the capability of making the planned path feasible and could be embedded in a path planning algorithm for an autonomous vehicle with kinematic constraints. It is concluded that the length of segments of the pre-planned path have to be greater than a nominal value, derived from the vehicle wheelbase, maximum steering angle and maximum speed to ensure the path for the autonomous car is feasible.

  4. Points-Based Safe Path Planning of Continuum Robots

    Directory of Open Access Journals (Sweden)

    Khuram Shahzad

    2015-07-01

    Full Text Available Continuum robots exhibit great potential in a number of challenging applications where traditional rigid link robots pose certain limitations, e.g., working in unstructured environments. In order to enable the usage of continuum robots in safety-critical applications, such as surgery and nuclear decontamination, it is extremely important to ensure a safe path for the robot's movement. Existing algorithms for continuum robot path planning have certain limitations that need to be addressed. These include the fact that none of the algorithms provide safety assurance parameters and control for path planning. They are computationally expensive, applicable to a specific type of continuum robots, and mostly they do not incorporate design and kinematics constraints. In this paper, we propose a points-based path planning (PoPP algorithm for continuum robots that computes the path by imposing safety constraints and improves upon the limitations of existing approaches. In the algorithm, we exploit the constant curvature-bending property of continuum robots in their path planning process. The algorithm is computationally efficient and provides a good tradeoff between accuracy and efficiency that can be implemented to enable the safety-critical application of continuum robots. This algorithm also provides information regarding path volume and flexibility in movement. Simulation results confirm that the algorithm possesses promising potential for all types of continuum robots (following the constant curvature-bending property. We believe that this effectively balances the desired safety and efficiency requirements.

  5. Path integral measure for first-order and metric gravities

    International Nuclear Information System (INIS)

    Aros, Rodrigo; Contreras, Mauricio; Zanelli, Jorge

    2003-01-01

    The equivalence between the path integrals for first-order gravity and the standard torsion-free, metric gravity in 3 + 1 dimensions is analysed. Starting with the path integral for first-order gravity, the correct measure for the path integral of the metric theory is obtained

  6. Extremal and Degree Conditions for Path Extendability in Digraphs

    NARCIS (Netherlands)

    Zhang, Zan-Bo; Zhang, Xiaoyan; Broersma, Hajo; Lou, Dingjun

    2017-01-01

    In the study of cycles and paths, the meta-conjecture of Bondy that sufficient conditions for Hamiltonicity often imply pancyclicity has motivated research on the existence of cycles and paths of many lengths. Hendry further introduced the stronger concepts of cycle extendability and path

  7. Teleconnection Paths via Climate Network Direct Link Detection.

    Science.gov (United States)

    Zhou, Dong; Gozolchiani, Avi; Ashkenazy, Yosef; Havlin, Shlomo

    2015-12-31

    Teleconnections describe remote connections (typically thousands of kilometers) of the climate system. These are of great importance in climate dynamics as they reflect the transportation of energy and climate change on global scales (like the El Niño phenomenon). Yet, the path of influence propagation between such remote regions, and weighting associated with different paths, are only partially known. Here we propose a systematic climate network approach to find and quantify the optimal paths between remotely distant interacting locations. Specifically, we separate the correlations between two grid points into direct and indirect components, where the optimal path is found based on a minimal total cost function of the direct links. We demonstrate our method using near surface air temperature reanalysis data, on identifying cross-latitude teleconnections and their corresponding optimal paths. The proposed method may be used to quantify and improve our understanding regarding the emergence of climate patterns on global scales.

  8. Survey of Robot 3D Path Planning Algorithms

    Directory of Open Access Journals (Sweden)

    Liang Yang

    2016-01-01

    Full Text Available Robot 3D (three-dimension path planning targets for finding an optimal and collision-free path in a 3D workspace while taking into account kinematic constraints (including geometric, physical, and temporal constraints. The purpose of path planning, unlike motion planning which must be taken into consideration of dynamics, is to find a kinematically optimal path with the least time as well as model the environment completely. We discuss the fundamentals of these most successful robot 3D path planning algorithms which have been developed in recent years and concentrate on universally applicable algorithms which can be implemented in aerial robots, ground robots, and underwater robots. This paper classifies all the methods into five categories based on their exploring mechanisms and proposes a category, called multifusion based algorithms. For all these algorithms, they are analyzed from a time efficiency and implementable area perspective. Furthermore a comprehensive applicable analysis for each kind of method is presented after considering their merits and weaknesses.

  9. Path entanglement of photons by non-local bunching

    International Nuclear Information System (INIS)

    Eisenberg, H.; Hodelin, J.; Khoury, G.; Bouwmeester, D.

    2005-01-01

    Full Text:Path entangled photon states can be used to overcome classical limits on the accuracy of interferometric measurements such as the diffraction limit. These states are superpositions of finding n photons in one out of two (or more) paths. Using stimulated parametric down-conversion, we propose and demonstrate a method for generating heralded multiphoton path entanglement, without applying post-selection. parametric down-conversion is relatively easy to produce compared to pure Fock states as demanded by other proposals. By a special coincidence detection at one down converted arm, the photons of the second arm non-locally bunch into the desired state. Entanglement in photon number is created between two polarization modes rather than two paths. A polarization beam-splitter and a 2 wave plate can translate between the two representations. The experimental generation of a two-photon path entangled state was detected by observing interference at half the photon wavelength. The scheme is generally extendable to higher photon numbers

  10. A fast spectrum dual path flow cermet reactor

    International Nuclear Information System (INIS)

    Anghaie, S.; Feller, G.J.; Peery, S.D.; Parsley, R.C.

    1993-01-01

    A cermet fueled, dual path fast reactor for space nuclear propulsion applications is conceptually designed. The reactor utilizes an outer annulus core and an inner cylindrical core with radial and axial reflector. The dual path flow minimizes the impact of power peaking near the radial reflector. Basic neutronics and core design aspects of the reactor are discussed. The dual path reactor is integrated into a 25000 lbf thrust nuclear rocket

  11. Polymer quantum mechanics some examples using path integrals

    International Nuclear Information System (INIS)

    Parra, Lorena; Vergara, J. David

    2014-01-01

    In this work we analyze several physical systems in the context of polymer quantum mechanics using path integrals. First we introduce the group averaging method to quantize constrained systems with path integrals and later we use this procedure to compute the effective actions for the polymer non-relativistic particle and the polymer harmonic oscillator. We analyze the measure of the path integral and we describe the semiclassical dynamics of the systems

  12. From path integrals to anyons

    International Nuclear Information System (INIS)

    Canright, G.S.

    1992-01-01

    I offer a pedagogical review of the homotopy arguments for fractional statistics in two dimensions. These arguments arise naturally in path-integral language since they necessarily consider the properties of paths rather than simply permutations. The braid group replaces the permutation group as the basic structure for quantum statistics; hence properties of the braid group on several surfaces are briefly discussed. Finally, the question of multiple (real-space) occupancy is addressed; I suggest that the ''traditional'' treatment of this question (ie, an assumption that many-anyon wavefunctions necessarily vanish for multiple occupancy) needs reexamination

  13. Multiagent path-finding in strategic games

    OpenAIRE

    Mihevc, Simon

    2014-01-01

    In this thesis I worked on creating, comparing and improving algorithms for multi-agent path planning on a domain typical for real-time strategy games. I implemented and compared Multiagent pathfinding using clearance and Multiagent pathfinding using independence detection and operator decomposition. I discovered that they had problems maintaining group compactness and took too long to calculate the path. I considerably improved the efficiency of both algorithms.

  14. Multi-rate path-following control for unmanned air vehicles

    NARCIS (Netherlands)

    Guerreiro Tome Antunes, D.J.; Silvestre, C.J.; Cunha, R.

    2008-01-01

    A methodology is provided to tackle the path-following integrated guidance and control problem for unmanned air vehicles with measured outputs available at different rates. The path-following problem is addressed by defining a suitable non-linear path dependent error space to express the vehicle’s

  15. Space-efficient path-reporting approximate distance oracles

    DEFF Research Database (Denmark)

    Elkin, Michael; Neiman, Ofer; Wulff-Nilsen, Christian

    2016-01-01

    We consider approximate path-reporting distance oracles, distance labeling and labeled routing with extremely low space requirements, for general undirected graphs. For distance oracles, we show how to break the nlog⁡n space bound of Thorup and Zwick if approximate paths rather than distances need...

  16. The phenotypic equilibrium of cancer cells: From average-level stability to path-wise convergence.

    Science.gov (United States)

    Niu, Yuanling; Wang, Yue; Zhou, Da

    2015-12-07

    The phenotypic equilibrium, i.e. heterogeneous population of cancer cells tending to a fixed equilibrium of phenotypic proportions, has received much attention in cancer biology very recently. In the previous literature, some theoretical models were used to predict the experimental phenomena of the phenotypic equilibrium, which were often explained by different concepts of stabilities of the models. Here we present a stochastic multi-phenotype branching model by integrating conventional cellular hierarchy with phenotypic plasticity mechanisms of cancer cells. Based on our model, it is shown that: (i) our model can serve as a framework to unify the previous models for the phenotypic equilibrium, and then harmonizes the different kinds of average-level stabilities proposed in these models; and (ii) path-wise convergence of our model provides a deeper understanding to the phenotypic equilibrium from stochastic point of view. That is, the emergence of the phenotypic equilibrium is rooted in the stochastic nature of (almost) every sample path, the average-level stability just follows from it by averaging stochastic samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Integrated robust controller for vehicle path following

    Energy Technology Data Exchange (ETDEWEB)

    Mashadi, Behrooz; Ahmadizadeh, Pouyan, E-mail: p-ahmadizadeh@iust.ac.ir; Majidi, Majid, E-mail: m-majidi@iust.ac.ir [Iran University of Science and Technology, School of Automotive Engineering (Iran, Islamic Republic of); Mahmoodi-Kaleybar, Mehdi, E-mail: m-mahmoodi-k@iust.ac.ir [Iran University of Science and Technology, School of Mechanical Engineering (Iran, Islamic Republic of)

    2015-02-15

    The design of an integrated 4WS+DYC control system to guide a vehicle on a desired path is presented. The lateral dynamics of the path follower vehicle is formulated by considering important parameters. To reduce the effect of uncertainties in vehicle parameters, a robust controller is designed based on a μ-synthesis approach. Numerical simulations are performed using a nonlinear vehicle model in MATLAB environment in order to investigate the effectiveness of the designed controller. Results of simulations show that the controller has a profound ability to making the vehicle track the desired path in the presence of uncertainties.

  18. Integrated robust controller for vehicle path following

    International Nuclear Information System (INIS)

    Mashadi, Behrooz; Ahmadizadeh, Pouyan; Majidi, Majid; Mahmoodi-Kaleybar, Mehdi

    2015-01-01

    The design of an integrated 4WS+DYC control system to guide a vehicle on a desired path is presented. The lateral dynamics of the path follower vehicle is formulated by considering important parameters. To reduce the effect of uncertainties in vehicle parameters, a robust controller is designed based on a μ-synthesis approach. Numerical simulations are performed using a nonlinear vehicle model in MATLAB environment in order to investigate the effectiveness of the designed controller. Results of simulations show that the controller has a profound ability to making the vehicle track the desired path in the presence of uncertainties

  19. Path integral representations on the complex sphere

    Energy Technology Data Exchange (ETDEWEB)

    Grosche, C. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2007-08-15

    In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S{sub 3C}. The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid. (orig.)

  20. Minimum dose method for walking-path planning of nuclear facilities

    International Nuclear Information System (INIS)

    Liu, Yong-kuo; Li, Meng-kun; Xie, Chun-li; Peng, Min-jun; Wang, Shuang-yu; Chao, Nan; Liu, Zhong-kun

    2015-01-01

    Highlights: • For radiation environment, the environment model is proposed. • For the least dose walking path problem, a path-planning method is designed. • The path-planning virtual–real mixed simulation program is developed. • The program can plan walking path and simulate. - Abstract: A minimum dose method based on staff walking road network model was proposed for the walking-path planning in nuclear facilities. A virtual–reality simulation program was developed using C# programming language and Direct X engine. The simulation program was used in simulations dealing with virtual nuclear facilities. Simulation results indicated that the walking-path planning method was effective in providing safety for people walking in nuclear facilities

  1. A sampling-based approach to probabilistic pursuit evasion

    KAUST Repository

    Mahadevan, Aditya; Amato, Nancy M.

    2012-01-01

    Probabilistic roadmaps (PRMs) are a sampling-based approach to motion-planning that encodes feasible paths through the environment using a graph created from a subset of valid positions. Prior research has shown that PRMs can be augmented

  2. Variational nature, integration, and properties of Newton reaction path.

    Science.gov (United States)

    Bofill, Josep Maria; Quapp, Wolfgang

    2011-02-21

    The distinguished coordinate path and the reduced gradient following path or its equivalent formulation, the Newton trajectory, are analyzed and unified using the theory of calculus of variations. It is shown that their minimum character is related to the fact that the curve is located in a valley region. In this case, we say that the Newton trajectory is a reaction path with the category of minimum energy path. In addition to these findings a Runge-Kutta-Fehlberg algorithm to integrate these curves is also proposed.

  3. Variational nature, integration, and properties of Newton reaction path

    Science.gov (United States)

    Bofill, Josep Maria; Quapp, Wolfgang

    2011-02-01

    The distinguished coordinate path and the reduced gradient following path or its equivalent formulation, the Newton trajectory, are analyzed and unified using the theory of calculus of variations. It is shown that their minimum character is related to the fact that the curve is located in a valley region. In this case, we say that the Newton trajectory is a reaction path with the category of minimum energy path. In addition to these findings a Runge-Kutta-Fehlberg algorithm to integrate these curves is also proposed.

  4. Quantum mechanics on the half-line using path integrals

    International Nuclear Information System (INIS)

    Clark, T.E.; Menikoff, R.; Sharp, D.H.

    1980-01-01

    We study the Feynman path-integral formalism for the constrained problem of a free particle moving on the half-line. It is shown that the effect of the boundary condition at the origin can be incorporated into the path integral by a simple modification of the action. The small-time behavior of the Green's function can be obtained from the stationary-phase evaluation of our expression for the path integral, which in this case includes contributions from both the direct and reflected classical paths

  5. Automated path length and M56 measurements at Jefferson Lab

    International Nuclear Information System (INIS)

    Hardy, D.; Tang, J.; Legg, R.

    1997-01-01

    Accurate measurement of path length and path length changes versus momentum (M 56 ) are critical for maintaining minimum beam energy spread in the CEBAF (Continuous Electron Beam Accelerator Facility) accelerator at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The relative path length for each circuit of the beam (1256m) must be equal within 1.5 degrees of 1497 MHz RF phase. A relative path length measurement is made by measuring the relative phases of RF signals from a cavity that is separately excited for each pass of a 4.2 μs pulsed beam. This method distinguishes the path length to less than 0.5 path length error. The development of a VME based automated measurement system for path length and M 56 has contributed to faster machine setup time and has the potential for use as a feedback parameter for automated control

  6. Hot gas path component having near wall cooling features

    Science.gov (United States)

    Miranda, Carlos Miguel; Kottilingam, Srikanth Chandrudu; Lacy, Benjamin Paul

    2017-11-28

    A method for providing micro-channels in a hot gas path component includes forming a first micro-channel in an exterior surface of a substrate of the hot gas path component. A second micro-channel is formed in the exterior surface of the hot gas path component such that it is separated from the first micro-channel by a surface gap having a first width. The method also includes disposing a braze sheet onto the exterior surface of the hot gas path component such that the braze sheet covers at least of portion of the first and second micro-channels, and heating the braze sheet to bond it to at least a portion of the exterior surface of the hot gas path component.

  7. Generalized measures and the Feynman path integral

    International Nuclear Information System (INIS)

    Maslov, V.P.; Chebotarev, A.M.

    1976-01-01

    Generalizations are obtained for the earlier results by the authors concerning the inclusion of the Feynmann path integral in the momentum representation into the general integration theory. Feynmann path integrals are considered which do not represent T-products. Generalized Feynmann measure in the configuration representation is introduced

  8. Approximate shortest homotopic paths in weighted regions

    KAUST Repository

    Cheng, Siuwing; Jin, Jiongxin; Vigneron, Antoine E.; Wang, Yajun

    2012-01-01

    A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative

  9. Line-of-Sight Path Following for Dubins Paths with Adaptive Sideslip Compensation of Drift Forces

    DEFF Research Database (Denmark)

    Fossen, Thor Inge; Pettersen, Kristin Ytterstad; Galeazzi, Roberto

    2015-01-01

    guidance law is intended for maneuvering in the horizontal-plane at given speeds and typical applications are marine craft, autonomous underwater vehicles (AUVs), unmanned aerial vehicles (UAVs) as well as other vehicles and craft where the goal is to follow a predefined parametrized curve without time......-sight (LOS) guidance principle used by ancient navigators, which is here extended to path following of Dubins paths. The unknown sideslip angle is treated as a constant parameter, which is estimated using an adaptation law. The equilibrium points of the cross-track and parameter estimation errors are proven...

  10. Life course path analysis of birth weight, childhood growth, and adult systolic blood pressure

    DEFF Research Database (Denmark)

    Gamborg, Michael; Andersen, Per Kragh; Baker, Jennifer L

    2009-01-01

    body size, and thereby the total effect, of size and changes in size on later outcomes. Using data on childhood body size and adult systolic blood pressure from a sample of 1,284 Danish men born between 1936 and 1970, the authors compared results from path analysis with results from 3 standard...... regression methods. Path analysis produced easily interpretable results, and compared with standard regression methods it produced a noteworthy gain in statistical power. The effect of change in relative body size on adult blood pressure was more pronounced after age 11 years than in earlier childhood....... These results suggest that increases in body size prior to age 11 years are less harmful to adult blood pressure than increases occurring after this age....

  11. REVISING THE INTOLERANCE OF UNCERTAINTY MODEL OF GENERALIZED ANXIETY DISORDER: EVIDENCE FROM UK AND ITALIAN UNDERGRADUATE SAMPLES

    Directory of Open Access Journals (Sweden)

    Gioia Bottesi

    2016-11-01

    Full Text Available The Intolerance of Uncertainty Model (IUM of Generalized Anxiety Disorder (GAD attributes a key role to Intolerance of Uncertainty (IU, and additional roles to Positive Beliefs about Worry (PBW, Negative Problem Orientation (NPO, and Cognitive Avoidance (CA, in the development and maintenance of worry, the core feature of GAD. Despite the role of the IUM components in worry and GAD has been considerably demonstrated, to date no studies have explicitly assessed whether and how PBW, NPO, and CA might turn IU into worry and somatic anxiety. The current studies sought to re-examine the IUM by assessing the relationships between the model’s components on two different non-clinical samples made up of UK and Italian undergraduate students. One-hundred and seventy UK undergraduates and 488 Italian undergraduates completed measures assessing IU, worry, somatic anxiety, depression, and refined measures of NPO, CA, and PBW. In each sample, two mediation models were conducted in order to test whether PBW, NPO, and CA differentially mediate the path from IU to worry and the path from IU to somatic anxiety. Secondly, it was tested whether IU also moderates the mediations. Main findings showed that, in the UK sample, only NPO mediated the path from IU to worry; as far as concern the path to anxiety, none of the putative mediators were significant. Differently, in the Italian sample PBW and NPO were mediators in the path from IU to worry, whereas only CA played a mediational role in the path from IU to somatic anxiety. Lastly, IU was observed to moderate only the association between NPO and worry, and only in the Italian sample. Some important cross-cultural, conceptual, and methodological issues raised from main results are discussed.

  12. Path Integrals in Quantum Mechanics

    International Nuclear Information System (INIS)

    Chetouani, L

    2005-01-01

    By treating path integrals the author, in this book, places at the disposal of the reader a modern tool for the comprehension of standard quantum mechanics. Thus the most important applications, such as the tunnel effect, the diffusion matrix, etc, are presented from an original point of view on the action S of classical mechanics while having it play a central role in quantum mechanics. What also emerges is that the path integral describes these applications more richly than are described traditionally by differential equations, and consequently explains them more fully. The book is certainly of high quality in all aspects: original in presentation, rigorous in the demonstrations, judicious in the choice of exercises and, finally, modern, for example in the treatment of the tunnel effect by the method of instantons. Moreover, the correspondence that exists between classical and quantum mechanics is well underlined. I thus highly recommend this book (the French version being already available) to those who wish to familiarize themselves with formulation by path integrals. They will find, in addition, interesting topics suitable for exploring further. (book review)

  13. Distribution definition of path integrals

    International Nuclear Information System (INIS)

    Kerler, W.

    1979-01-01

    By starting from quantum mechanics it turns out that a rather general definition of quantum functional integrals can be given which is based on distribution theory. It applies also to curved space and provides clear rules for non-linear transformations. The refinements necessary in usual definitions of path integrals are pointed out. Since the quantum nature requires special care with time sequences, it is not the classical phase space which occurs in the phase-space form of the path integral. Feynman's configuration-space form only applies to a highly specialized situation, and therefore is not a very advantageous starting point for general investigations. It is shown that the commonly used substitutions of variables do not properly account for quantum effects. The relation to the traditional ordering problem is clarified. The distribution formulation has allowed to treat constrained systems directly at the quantum level, to complete the path integral formulation of the equivalence theorem, and to define functional integrals also for space translation after the transition to fields. (orig.)

  14. Technology Paths in Energy-Efficient and Sustainable Construction

    DEFF Research Database (Denmark)

    Holm, Jesper; Lund Sørensen, Runa Cecilie

    2015-01-01

    Various tehcnology paths and regimes, Building codes and standards in energy, eco and sustainable housing......Various tehcnology paths and regimes, Building codes and standards in energy, eco and sustainable housing...

  15. Approximate Shortest Homotopic Paths in Weighted Regions

    KAUST Repository

    Cheng, Siu-Wing; Jin, Jiongxin; Vigneron, Antoine; Wang, Yajun

    2010-01-01

    Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P

  16. Two Generations of Path Dependence in Economics?

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    2010-01-01

    Even if there is no fully articulated and generally accepted theory of Path Dependence it has eagerly been taken up across a wide range of social sciences – primarily coming from economics. Path Dependence is most of all a metaphor that offers reason to believe, that some political, social...

  17. from synchronic variation to a grammaticalization path

    African Journals Online (AJOL)

    Kate H

    Abstract. The authors argue that the synchronic variation of cognate objects of weather verbs exhibited in six African languages of South Africa (Sepedi, Sesotho, Tshivenda, isiXhosa, Xitsonga, and. isiZulu) has a diachronic explanation, and may be represented as a grammaticalization path. This path gradually leads from ...

  18. Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

    Science.gov (United States)

    Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

    2018-04-01

    Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

  19. Soil water retention curves of remoulded clay on drying and wetting paths

    International Nuclear Information System (INIS)

    Zhang Xiwei; Zhang Jian

    2010-01-01

    The present research focuses on the laboratory measurement of the Soil Water Retention Curve (SWRC), that expresses the relationship between water content (gravimetric or volumetric) or degree of saturation and soil suction. The SWRC plays an important role in an unsaturated soil mechanics framework and is required for the numerical modelling of any process of flow and transport in unsaturated soil problems, already as a part of constitutive model of unsaturated soil. Six remoulded London Clay samples were performed SWRC testing on the drying and wetting path, meanwhile measurement the volume change. The effect of initial water content and various drying/wetting paths were considered in the tests. The results of SWRC show that hysteretic characteristic in boundary drying/wetting curve, the water holding capacity was increased due to the increase of the initial water content. The shape of the SWRC strongly depended on the volume change. (authors)

  20. Reactive Path Planning Approach for Docking Robots in Unknown Environment

    Directory of Open Access Journals (Sweden)

    Peng Cui

    2017-01-01

    Full Text Available Autonomous robots need to be recharged and exchange information with the host through docking in the long-distance tasks. Therefore, feasible path is required in the docking process to guide the robot and adjust its pose. However, when there are unknown obstacles in the work area, it becomes difficult to determine the feasible path for docking. This paper presents a reactive path planning approach named Dubins-APF (DAPF to solve the path planning problem for docking in unknown environment with obstacles. In this proposed approach the Dubins curves are combined with the designed obstacle avoidance potential field to plan the feasible path. Firstly, an initial path is planned and followed according to the configurations of the robot and the docking station. Then when the followed path is evaluated to be infeasible, the intermediate configuration is calculated as well as the replanned path based on the obstacle avoidance potential field. The robot will be navigated to the docking station with proper pose eventually via the DAPF approach. The proposed DAPF approach is efficient and does not require the prior knowledge about the environment. Simulation results are given to validate the effectiveness and feasibility of the proposed approach.

  1. Extended depth measurement for a Stokes sample imaging polarimeter

    Science.gov (United States)

    Dixon, Alexander W.; Taberner, Andrew J.; Nash, Martyn P.; Nielsen, Poul M. F.

    2018-02-01

    A non-destructive imaging technique is required for quantifying the anisotropic and heterogeneous structural arrangement of collagen in soft tissue membranes, such as bovine pericardium, which are used in the construction of bioprosthetic heart valves. Previously, our group developed a Stokes imaging polarimeter that measures the linear birefringence of samples in a transmission arrangement. With this device, linear retardance and optic axis orientation; can be estimated over a sample using simple vector algebra on Stokes vectors in the Poincaré sphere. However, this method is limited to a single path retardation of a half-wave, limiting the thickness of samples that can be imaged. The polarimeter has been extended to allow illumination of narrow bandwidth light of controllable wavelength through achromatic lenses and polarization optics. We can now take advantage of the wavelength dependence of relative retardation to remove ambiguities that arise when samples have a single path retardation of a half-wave to full-wave. This effectively doubles the imaging depth of this method. The method has been validated using films of cellulose of varied thickness, and applied to samples of bovine pericardium.

  2. Some instructive examples of Mayer's interference in path integral

    International Nuclear Information System (INIS)

    Fiziev, P.P.

    1984-01-01

    A new technique of path integral evaluation by a discretization procedure is proposed. It is based on the requirement, found previously, to single out the set of classical trajectories over which the summation is performed. The notion of Mayer's interference is introduced and illustrated by a number of simple examples. The choice of the set of paths is shown to induce a corresponding quantization procedure and this line is followed to demonstrate its connection with the symmetries of the problem. The possibility of extracting information on the space of quantum states from path integrals has been reviewed. A class of paths has been found; the summation over these paths within the framework of the suggested approach produces the well known results for the motion in a homogeneous field and for the harmonic oscillator

  3. Quad-rotor flight path energy optimization

    Science.gov (United States)

    Kemper, Edward

    Quad-Rotor unmanned areal vehicles (UAVs) have been a popular area of research and development in the last decade, especially with the advent of affordable microcontrollers like the MSP 430 and the Raspberry Pi. Path-Energy Optimization is an area that is well developed for linear systems. In this thesis, this idea of path-energy optimization is extended to the nonlinear model of the Quad-rotor UAV. The classical optimization technique is adapted to the nonlinear model that is derived for the problem at hand, coming up with a set of partial differential equations and boundary value conditions to solve these equations. Then, different techniques to implement energy optimization algorithms are tested using simulations in Python. First, a purely nonlinear approach is used. This method is shown to be computationally intensive, with no practical solution available in a reasonable amount of time. Second, heuristic techniques to minimize the energy of the flight path are tested, using Ziegler-Nichols' proportional integral derivative (PID) controller tuning technique. Finally, a brute force look-up table based PID controller is used. Simulation results of the heuristic method show that both reliable control of the system and path-energy optimization are achieved in a reasonable amount of time.

  4. Directed paths in a layered environment

    International Nuclear Information System (INIS)

    Alvarez, J; Janse van Rensburg, E J

    2008-01-01

    A polymer in a layered environment is modeled as a directed path in a layered square lattice composed of alternating A-layers of width w a and B-layers of width w b . In this paper we consider general cases of this model, where edges in the path interact with the layers, and vertices in the path interact with interfaces between adjacent layers. The phase diagram exhibits different regimes. In particular, we found that the path may be localized to one layer, be adsorbed on an interface between two layers or be delocalized across layers. We examine special aspects of the model in detail: the asymptotic regimes of the models are examined, and entropic forces on the interfaces are determined. We focus on several different cases, including models with layers of equal or similar width. More general models of layers with different but finite widths, or with one layer of infinite width, are also examined in detail. Several of these models exhibit phase behavior which relate to well-studied polymer phase behavior such as adsorption at an impenetrable wall, pinning at an interface between two immiscible solvents, steric stabilization of colloidal particles and sensitized flocculation of colloidal particles by polymers

  5. New framework for the Feynman path integral

    International Nuclear Information System (INIS)

    Shaharir, M.Z.

    1986-01-01

    The well-known Fourier integral solution of the free diffusion equation in an arbitrary Euclidean space is reduced to Feynmannian integrals using the method partly contained in the formulation of the Fresnelian integral. By replacing the standard Hilbert space underlying the present mathematical formulation of the Feynman path integral by a new Hilbert space, the space of classical paths on the tangent bundle to the Euclidean space (and more general to an arbitrary Riemannian manifold) equipped with a natural inner product, we show that our Feynmannian integral is in better agreement with the qualitative features of the original Feynman path integral than the previous formulations of the integral

  6. Path space measures for Dirac and Schroedinger equations: Nonstandard analytical approach

    International Nuclear Information System (INIS)

    Nakamura, T.

    1997-01-01

    A nonstandard path space *-measure is constructed to justify the path integral formula for the Dirac equation in two-dimensional space endash time. A standard measure as well as a standard path integral is obtained from it. We also show that, even for the Schroedinger equation, for which there is no standard measure appropriate for a path integral, there exists a nonstandard measure to define a *-path integral whose standard part agrees with the ordinary path integral as defined by a limit from time-slice approximant. copyright 1997 American Institute of Physics

  7. Analysis Of Economic Motivation When Individuals Choose An Educational Path

    Directory of Open Access Journals (Sweden)

    Viktor Anatolyevich Koksharov

    2015-03-01

    Full Text Available The authors consider the economic motivations when individuals choose an educational path. This line of research is relevant from both, the point of view of science — research of economic behavior of an individual, and the point of view of practice — allows to increase efficiency of investments in a human capital. The authors have developed the economic and mathematical model of choice of optimum educational paths by individuals. The model is realized in the software and approved on real data on more than 5,5 thousand students. For the analysis of the importance of rational economic expectations when an educational path has to be chosen, the paths chosen by students is compared and the educational paths optimum from the point of view of economic rationality are calculated. The analysis of the results has showed that mainly, the choice of educational paths happens according to the economic motivations. On the considered selection, 66 % of prospective students have chosen an optimum path from the point of view of economic preferences. The most significant factor providing development of optimum educational paths is an expectation of higher income upon completion of education — 22 % of all educational paths, and a possibility of cost-cutting of educating or state-subsidized education — 12 %. In our opinion, one of the most important practical results of the research of optimum educational path is the need to consider expectations of students and prospective student when developing a state policy of investment in human capital.

  8. Reaction path simulations in multicomponent materials

    International Nuclear Information System (INIS)

    Seifert, H.J.

    1999-01-01

    The CALPHAD (calculation of phase diagrams) method is used in combination with selected experimental investigations to derive reaction paths in multicomponent systems. The method is illustrated by applying computerized thermodynamic databases and suitable software to explain quantitatively the thermal degradation of precursor-derived Si-C-N ceramics and the nitridation of titanium carbide. Reaction sequences in the Si 3 N 4 -SiC-TiC x N l-x -C-N system are illustrated by graphical representation of compatibility regions and indicated reaction paths. From these results the experimentally known microstructure development of TiC reinforced Si 3 N 4 ceramics is explained and quantitative information is provided to optimize the microstructure of such materials. The concept of reaction paths for the understanding of rapid solidification processes is shown by the example of AZ type Mg casting alloys. (orig.)

  9. Rare events in many-body systems: reactive paths and reaction constants for structural transitions

    International Nuclear Information System (INIS)

    Picciani, M.

    2012-01-01

    This PhD thesis deals with the study of fundamental physics phenomena, with applications to nuclear materials of interest. We have developed methods for the study of rare events related to thermally activated structural transitions in many body systems. The first method involves the numerical simulation of the probability current associated with reactive paths. After deriving the evolution equations for the probability current, a Diffusion Monte Carlo algorithm is implemented in order to sample this current. This technique, called Transition Current Sampling was applied to the study of structural transitions in a cluster of 38 atoms with Lennard-Jones potential (LJ-38). A second algorithm, called Transition Path Sampling with local Lyapunov bias (LyTPS), was then developed. LyTPS calculates reaction rates at finite temperature by following the transition state theory. A statistical bias based on the maximum local Lyapunov exponents is introduced to accelerate the sampling of reactive trajectories. To extract the value of the equilibrium reaction constants obtained from LyTPS, we use the Multistate Bennett Acceptance Ratio. We again validate this method on the LJ-38 cluster. LyTPS is then used to calculate migration constants for vacancies and divacancies in the α-Iron, and the associated migration entropy. These constants are used as input parameter for codes modeling the kinetic evolution after irradiation (First Passage Kinetic Monte Carlo) to reproduce numerically resistivity recovery experiments in α-Iron. (author) [fr

  10. Interactions of information transfer along separable causal paths

    Science.gov (United States)

    Jiang, Peishi; Kumar, Praveen

    2018-04-01

    Complex systems arise as a result of interdependences between multiple variables, whose causal interactions can be visualized in a time-series graph. Transfer entropy and information partitioning approaches have been used to characterize such dependences. However, these approaches capture net information transfer occurring through a multitude of pathways involved in the interaction and as a result mask our ability to discern the causal interaction within a subgraph of interest through specific pathways. We build on recent developments of momentary information transfer along causal paths proposed by Runge [Phys. Rev. E 92, 062829 (2015), 10.1103/PhysRevE.92.062829] to develop a framework for quantifying information partitioning along separable causal paths. Momentary information transfer along causal paths captures the amount of information transfer between any two variables lagged at two specific points in time. Our approach expands this concept to characterize the causal interaction in terms of synergistic, unique, and redundant information transfer through separable causal paths. Through a graphical model, we analyze the impact of the separable and nonseparable causal paths and the causality structure embedded in the graph as well as the noise effect on information partitioning by using synthetic data generated from two coupled logistic equation models. Our approach can provide a valuable reference for an autonomous information partitioning along separable causal paths which form a causal subgraph influencing a target.

  11. Low level constraints on dynamic contour path integration.

    Directory of Open Access Journals (Sweden)

    Sophie Hall

    Full Text Available Contour integration is a fundamental visual process. The constraints on integrating discrete contour elements and the associated neural mechanisms have typically been investigated using static contour paths. However, in our dynamic natural environment objects and scenes vary over space and time. With the aim of investigating the parameters affecting spatiotemporal contour path integration, we measured human contrast detection performance of a briefly presented foveal target embedded in dynamic collinear stimulus sequences (comprising five short 'predictor' bars appearing consecutively towards the fovea, followed by the 'target' bar in four experiments. The data showed that participants' target detection performance was relatively unchanged when individual contour elements were separated by up to 2° spatial gap or 200 ms temporal gap. Randomising the luminance contrast or colour of the predictors, on the other hand, had similar detrimental effect on grouping dynamic contour path and subsequent target detection performance. Randomising the orientation of the predictors reduced target detection performance greater than introducing misalignment relative to the contour path. The results suggest that the visual system integrates dynamic path elements to bias target detection even when the continuity of path is disrupted in terms of spatial (2°, temporal (200 ms, colour (over 10 colours and luminance (-25% to 25% information. We discuss how the findings can be largely reconciled within the functioning of V1 horizontal connections.

  12. Transition paths in single-molecule force spectroscopy.

    Science.gov (United States)

    Cossio, Pilar; Hummer, Gerhard; Szabo, Attila

    2018-03-28

    In a typical single-molecule force spectroscopy experiment, the ends of the molecule of interest are connected by long polymer linkers to a pair of mesoscopic beads trapped in the focus of two laser beams. At constant force load, the total extension, i.e., the end-to-end distance of the molecule plus linkers, is measured as a function of time. In the simplest systems, the measured extension fluctuates about two values characteristic of folded and unfolded states, with occasional transitions between them. We have recently shown that molecular (un)folding rates can be recovered from such trajectories, with a small linker correction, as long as the characteristic time of the bead fluctuations is shorter than the residence time in the unfolded (folded) state. Here, we show that accurate measurements of the molecular transition path times require an even faster apparatus response. Transition paths, the trajectory segments in which the molecule (un)folds, are properly resolved only if the beads fluctuate more rapidly than the end-to-end distance of the molecule. Therefore, over a wide regime, the measured rates may be meaningful but not the transition path times. Analytic expressions for the measured mean transition path times are obtained for systems diffusing anisotropically on a two-dimensional free energy surface. The transition path times depend on the properties both of the molecule and of the pulling device.

  13. A career path in clinical pathways.

    Science.gov (United States)

    Bower, K A

    1998-03-01

    Much like the development of a clinical path, the creation of a career path requires knowledge of patterns of behavior, needs for standardized education and skill development, along with variance analysis and individualized care. This nationally known nursing entrepreneur tells the story of her involvement in the development of case management and clinical pathways and how she turned that into a successful business that has changed how patient care is managed nationally and internationally.

  14. Experimental demonstration of spectrum-sliced elastic optical path network (SLICE).

    Science.gov (United States)

    Kozicki, Bartłomiej; Takara, Hidehiko; Tsukishima, Yukio; Yoshimatsu, Toshihide; Yonenaga, Kazushige; Jinno, Masahiko

    2010-10-11

    We describe experimental demonstration of spectrum-sliced elastic optical path network (SLICE) architecture. We employ optical orthogonal frequency-division multiplexing (OFDM) modulation format and bandwidth-variable optical cross-connects (OXC) to generate, transmit and receive optical paths with bandwidths of up to 1 Tb/s. We experimentally demonstrate elastic optical path setup and spectrally-efficient transmission of multiple channels with bit rates ranging from 40 to 140 Gb/s between six nodes of a mesh network. We show dynamic bandwidth scalability for optical paths with bit rates of 40 to 440 Gb/s. Moreover, we demonstrate multihop transmission of a 1 Tb/s optical path over 400 km of standard single-mode fiber (SMF). Finally, we investigate the filtering properties and the required guard band width for spectrally-efficient allocation of optical paths in SLICE.

  15. comparative analysis and implementation of dijkstra's shortest path

    African Journals Online (AJOL)

    user

    path problem requires finding a single shortest-path between given vertices s and t; ... Bridge in 1735, [5 – 10]. This problem led to the .... their advancements from new design paradigms, data structures ..... .

  16. Determination and optimization of spatial samples for distributed measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Xiaoming (Georgia Institute of Technology, Atlanta, GA); Tran, Hy D.; Shilling, Katherine Meghan; Kim, Heeyong (Georgia Institute of Technology, Atlanta, GA)

    2010-10-01

    There are no accepted standards for determining how many measurements to take during part inspection or where to take them, or for assessing confidence in the evaluation of acceptance based on these measurements. The goal of this work was to develop a standard method for determining the number of measurements, together with the spatial distribution of measurements and the associated risks for false acceptance and false rejection. Two paths have been taken to create a standard method for selecting sampling points. A wavelet-based model has been developed to select measurement points and to determine confidence in the measurement after the points are taken. An adaptive sampling strategy has been studied to determine implementation feasibility on commercial measurement equipment. Results using both real and simulated data are presented for each of the paths.

  17. Toward solving the sign problem with path optimization method

    Science.gov (United States)

    Mori, Yuto; Kashiwa, Kouji; Ohnishi, Akira

    2017-12-01

    We propose a new approach to circumvent the sign problem in which the integration path is optimized to control the sign problem. We give a trial function specifying the integration path in the complex plane and tune it to optimize the cost function which represents the seriousness of the sign problem. We call it the path optimization method. In this method, we do not need to solve the gradient flow required in the Lefschetz-thimble method and then the construction of the integration-path contour arrives at the optimization problem where several efficient methods can be applied. In a simple model with a serious sign problem, the path optimization method is demonstrated to work well; the residual sign problem is resolved and precise results can be obtained even in the region where the global sign problem is serious.

  18. Path Following in the Exact Penalty Method of Convex Programming.

    Science.gov (United States)

    Zhou, Hua; Lange, Kenneth

    2015-07-01

    Classical penalty methods solve a sequence of unconstrained problems that put greater and greater stress on meeting the constraints. In the limit as the penalty constant tends to ∞, one recovers the constrained solution. In the exact penalty method, squared penalties are replaced by absolute value penalties, and the solution is recovered for a finite value of the penalty constant. In practice, the kinks in the penalty and the unknown magnitude of the penalty constant prevent wide application of the exact penalty method in nonlinear programming. In this article, we examine a strategy of path following consistent with the exact penalty method. Instead of performing optimization at a single penalty constant, we trace the solution as a continuous function of the penalty constant. Thus, path following starts at the unconstrained solution and follows the solution path as the penalty constant increases. In the process, the solution path hits, slides along, and exits from the various constraints. For quadratic programming, the solution path is piecewise linear and takes large jumps from constraint to constraint. For a general convex program, the solution path is piecewise smooth, and path following operates by numerically solving an ordinary differential equation segment by segment. Our diverse applications to a) projection onto a convex set, b) nonnegative least squares, c) quadratically constrained quadratic programming, d) geometric programming, and e) semidefinite programming illustrate the mechanics and potential of path following. The final detour to image denoising demonstrates the relevance of path following to regularized estimation in inverse problems. In regularized estimation, one follows the solution path as the penalty constant decreases from a large value.

  19. Automatic path proposal computation for CT-guided percutaneous liver biopsy.

    Science.gov (United States)

    Helck, A; Schumann, C; Aumann, J; Thierfelder, K; Strobl, F F; Braunagel, M; Niethammer, M; Clevert, D A; Hoffmann, R T; Reiser, M; Sandner, T; Trumm, C

    2016-12-01

    To evaluate feasibility of automatic software-based path proposals for CT-guided percutaneous biopsies. Thirty-three patients (60 [Formula: see text] 12 years) referred for CT-guided biopsy of focal liver lesions were consecutively included. Pre-interventional CT and dedicated software (FraunhoferMeVis Pathfinder) were used for (semi)automatic segmentation of relevant structures. The software subsequently generated three path proposals in downward quality for CT-guided biopsy. Proposed needle paths were compared with consensus proposal of two experts (comparable, less suitable, not feasible). In case of comparable results, equivalent approach to software-based path proposal was used. Quality of segmentation process was evaluated (Likert scale, 1 [Formula: see text] best, 6 [Formula: see text] worst), and time for processing was registered. All biopsies were performed successfully without complications. In 91 % one of the three automatic path proposals was rated comparable to experts' proposal. None of the first proposals was rated not feasible, and 76 % were rated comparable to the experts' proposal. 7 % automatic path proposals were rated not feasible, all being second choice ([Formula: see text]) or third choice ([Formula: see text]). In 79 %, segmentation at least was good. Average total time for establishing automatic path proposal was 42 [Formula: see text] 9 s. Automatic software-based path proposal for CT-guided liver biopsies in the majority provides path proposals that are easy to establish and comparable to experts' insertion trajectories.

  20. Which coordinate system for modelling path integration?

    Science.gov (United States)

    Vickerstaff, Robert J; Cheung, Allen

    2010-03-21

    Path integration is a navigation strategy widely observed in nature where an animal maintains a running estimate, called the home vector, of its location during an excursion. Evidence suggests it is both ancient and ubiquitous in nature, and has been studied for over a century. In that time, canonical and neural network models have flourished, based on a wide range of assumptions, justifications and supporting data. Despite the importance of the phenomenon, consensus and unifying principles appear lacking. A fundamental issue is the neural representation of space needed for biological path integration. This paper presents a scheme to classify path integration systems on the basis of the way the home vector records and updates the spatial relationship between the animal and its home location. Four extended classes of coordinate systems are used to unify and review both canonical and neural network models of path integration, from the arthropod and mammalian literature. This scheme demonstrates analytical equivalence between models which may otherwise appear unrelated, and distinguishes between models which may superficially appear similar. A thorough analysis is carried out of the equational forms of important facets of path integration including updating, steering, searching and systematic errors, using each of the four coordinate systems. The type of available directional cue, namely allothetic or idiothetic, is also considered. It is shown that on balance, the class of home vectors which includes the geocentric Cartesian coordinate system, appears to be the most robust for biological systems. A key conclusion is that deducing computational structure from behavioural data alone will be difficult or impossible, at least in the absence of an analysis of random errors. Consequently it is likely that further theoretical insights into path integration will require an in-depth study of the effect of noise on the four classes of home vectors. Copyright 2009 Elsevier Ltd