Kinematic Events Research Articles

The Perception of Relative Mass in Physical Collisions

Researchers (Gilden & Proffitt, 1989; Runeson & Vedeler, 1993; Todd & Warren, 1982) have tested Runeson's (1977) claim that the relation between a collision . . event's dynamics and kinematics might support perception of the relative mass of colliding objects. Results have been inconsistent; however, these studies employed computer-generated collisions as stimuli. The present research assessed observer's ability to report relative mass in the context of physical objects involved in physical collisions. The results indicate greater sensitivity to relative mass than had been found with animations-based studies. Implications of these data for the kinematic specification of dynamics (KSD) principle of dynamics perception (Runeson & Frykholm, 1983) and a cue-heuristics theory of dynamics perception (Gilden & Proffitt, 1989) are discussed.

On colour rearrangement in hadronicW +W− evemts

We discuss the possibility of colour rearrangement in $\ee \to \W^+ \W^- \to \q_1 \qbar_2 \q_3 \qbar_4$ events, i.e.\ that the original colour singlets $\q_1 \qbar_2$ and $\q_3 \qbar_4$ may be transmuted, for instance, into new singlets $\q_1 \qbar_4$ and $\q_3 \qbar_2$. The effects on event properties could be quite large if such a rearrangement would occur instantaneously, so that gluon emission would be restricted to each of the new singlets separately. We argue that such a scenario is unlikely for two reasons. Firstly, the $\W^+$ and $\W^-$ usually decay at separate times after the $\W^+\W^-$ production, which leads to large relative phases for energetic radiation off the two constituents of a rearranged system, and a corresponding dampening of the QCD cascades. Secondly, within the perturbative scenario the colour transmutation appears only in order $\alpha_s^2$ and is colour-suppressed. Colour reconnection at longer time scales is quite feasible, however, and may affect the fragmentation phase. If so, the nature of non-perturbative QCD can be probed in a new way. We formulate several alternative toy models and use these to estimate the colour reconnection probability as a function of the event kinematics. Possible consequences for LEP~2 events are illustrated, with special attention to systematic errors in $\W$ mass determinations.

On coordinate systems and the representation of articulatory movements

Hypothetical examples are used to demonstrate how certain quantitative characterizations of kinematic events can be affected by the placement and orientation of reference axes against which measurements are made. The variation in coordinate systems among a representative sample of recent publications describing speech movements and postures is summarized, and a standard, easily defined coordinate system for future descriptions is proposed. Interpretative benefits associated with the proposed representational standard are noted.

Hard QED radiation at HERA

The deep-inelastic electron-proton collisions at HERA are frequently associated with emission of hard photons. A large fraction of these events can be identified either by the direct detection of radiative photons or, indirectly, by a mismatch between the event kinematics determined from the scattered electron energy and its angle and that determined from the hadronic flow associated with a deep-inelastic scattering. This unique feature of HERA experiments provides an experimental check on the size of radiative corrections. The emission of photons collinear with the incident electrons leads to a reduction of the effective beam energy. This effect can be used to measure the longitudinal structure function.

Measurement of the tau -lepton mass.

Using data from the CLEO II detector at CESR, we measure the [tau]-lepton mass by exploiting the unique kinematics of events in which both [tau]'s decay hadronically. The result is [ital m][sub [tau]]=1777.8[plus minus]0.7[plus minus]1.7 MeV/[ital c][sup 2]. By comparing our result with other measurements near [tau]-pair threshold, we extract an upper limit on the [tau]-neutrino mass of 75 MeV/[ital c][sup 2] at 95% confidence level.

Temporal Reasoning: What Develops?

How is time handled in kinematic and non-kinematic events from childhood to adulthood? Do subjects take one dimension or two dimensions into account to infer a third relationship? What occurs when the temporal information is presented in a hypothetical form (premises and conclusion)? A theoretical model based on empirical data from children, adolescent and adults is presented to describe the organization and development of relations across three dimensions in kinematics (i.e., relations between duration, beginning and ending times). The basic assumption of the model is that temporal dimensions are combined pairwise (dyadic relations) within structurally stable and structurally unstable cognitive systems, before yielding to undecidability concept (last level of triadic relations). Some predications of the model for decidable and undecidable time problems are presented. Data analysis shows that, even for adults, the concept of undecidability is constructed much later for non-kinematic events (i.e., in problems concerned with duration and succession) than for kinematic events when the information is presented in a hypothetical form (written or oral statements)

Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland

A Variscan,deep-crustal-level (eclogite-facies),continental basement massif in western Poland, the Snieznik complex, was tectonically exhumed. Crustal-penetrating mylonite zones record three main kinematic events: early top-to-the-north-directed thrusting, right-slip transpression-tension, and late top-to-the-south and -east normal faulting. Thrusting resulted in extreme crustal thickening and associated eclogite-facies metamorphism. Right-slip movements produced retrogressive crystal-plastic simple-shear zones. Normal faults flank Carboniferous to Early Permian terrigenous sedimentary basins, documenting tectonic and erosional denudation of the Snieznik complex during lithospheric extension. Sm/Nd isotopic dates previously reported for the in situ eclogite-facies metamorphic mineral assemblages are 341, 337, and 329 Ma (Brueckner et al., 1991). 40 Ar/ 39 Ar isotopic dates for metamorphic hornblende (338, 333, and 332 Ma), muscovite (329 and 329 Ma), and biotite (328 Ma) reflect times of cooling through the ∼500, 350, and 300 °C isotherms, respectively. These nearly concordant mineral dates document rapid cooling from ∼850 °C (eclogue-facies temperatures) to ∼300 °C. Rapid denudation of these deep-crustal rocks (∼19-22 kbar pressures, >70 km depth) is attributed to processes, similar to those of metamorphic-core complexes, that operated during lithospheric delamination and gravitational collapse. The sequence of late Paleozoic (Alleghanian) crustal thickening followed by right-slip transpression-tension followed by normal faulting recognized in the U.S. Appalachians implies that this tectonic pattern may exist throughout the Afleghanian-Variscan belt.

Absolute triple differential cross sections for helium at 300 eV

Absolute triple differential cross sections for the ionisation of He by electrons with energies near 300 eV have been measured in asymmetric conditions. The kinematics of the experiment select ionising events which belong to the intermediate regime of energy and momentum transfer. The experiments are compared with the distorted wave Born approximation.

Effects of vocal task and respiratory phase on prephonatory chest wall movements.

A vocal reaction time paradigm was used to explore prephonatory respiratory kinematics. Movements of the rib cage and abdomen were recorded prior to production of utterances differing in length and intensity, and vocal responses were elicited in different phases and volumes of the quiet breathing cycle. A velocity threshold was used to distinguish prephonatory adjustments from the cyclical movements of the chest wall that are characteristic of quiet breathing. The results suggest that a variety of prephonatory kinematic events can occur prior to initiation of vocalization in response to a stimulus. Further, prephonatory movements appear to be adaptive in that they are influenced by the length of the utterance to be spoken and the respiratory volume at the time of voice initiation.

An entity relationship approach to the event and detector monte carlo simulation in high-energy physics

A new system has been implemented for Monte Carlo simulation purposes in the framework of CERN/LAA-MSL Project, to deal with the ever-growing complexity of event and detector simulation in high-energy physics. The system, called FMC (Full Monte-Carlo Chain), comprehends three independent subsystems to define particles and decay properties, PDKDB (Particle and Decay Data Base), to describe the detector configuration, Set-Up Descriptor (SUD), and to deal with the event kinematics via interfacing routines among various Event Generators (EGs), the MEGA (Monte Carlo Event Generator Adaptor). An extensive use of the Entity Relationship techniques has been made to model the data with particular care on consistency and compatibility. By integrating the system to the GEANT tracking program, a complete simulation chain is obtained.

The Mechanism of Tongue Protraction During Prey Capture in the Frog Discoglossus Pictus

The mechanism of tongue protraction in the archaeobatrachian frog Discoglossus pictus was studied using high-speed video motion analysis before and after denervation of the submentalis and genioglossus muscles. The kinematics of prey capture were compared (1) between successful and unsuccessful feeding attempts before surgery; (2) before and after denervation of the m. submentalis; and (3) before and after denervation of the m. genioglossus. Prey capture by D. pictus is similar to that of Ascaphus truei, hypothesized to be the sister group of all other living frogs. These archaeobatrachians have tongues of limited protrusibility (maximum tongue reach=0.21-0.27cm) and lunge forward with the whole body to catch prey. In Discoglossus, unsuccessful attempts to capture prey differ from successful captures in having a longer duration of most kinematic variables. These results suggest that kinematic events are postponed in unsuccessful attempts at prey capture, owing to the absence of the somatosensory feedback that results from successful prey contact. Denervation of the m. submentalis prevents mandibular bending, but does not affect tongue protraction. Denervation of the m. genioglossus significantly decreases maximum tongue reach and maximum tongue height, but does not affect mandibular bending. The m. submentalis is necessary for mandibular bending, but neither mandibular bending nor m. submentalis activity are necessary or sufficient for tongue protraction. The m. genioglossus is necessary for normal tongue protraction. It does more than stiffen and support the tongue. These results are not consistent with the current model of tongue protraction developed for the neobatrachian toad Bufo marinus. If this model withstands the denervation test in Bufo marinus, then archaeobatrachians and neobatrachians must differ in their mechanisms of tongue protraction. Note: Present address: Brain Research Institute FB2, University of Bremen, D-2800 Bremen, Federal Republic of Germany.

Jurassic normal and strike-slip faults at Crater Island, northwestern Utah

At Crater Island, northern Silver Island Mountains, northwestern Utah, an unbroken Tertiary fault block within the Basin and Range province exhibits Jurassic or older structures that are virtually unmodified by subsequent tectonism, providing an opportunity to examine the tectonics of the Jurassic back arc of the Cordillera. Widespread high-angle faults, mainly striking north and northeast, offset the moderately west-dipping strata down to the west, thereby extending the strata parallel to bedding by 10% to 20%. These faults apparently belong to a single kinematic event of west-northwest oriented extension subparallel to bedding. The normal faults merge with a north-northwest dextral strike-slip fault system. The two fault systems are kinematically compatible, suggesting that they may have been contemporaneous. A low-angle (thrust?) fault nearly parallel to bedding within Ordovician strata is cut by the high-angle faults. Intrusive relations with about 160 Ma granitoid rocks show that all of these faults are Late Jurassic or older, with a reasonable lower age limit of Early Jurassic established on the basis of paleogeographic reconstructions using sedimentary deposits in the region. Jurassic dikes indicate a minimum horizontal compression direction that is parallel to the extension direction indicated by the normal faults, thus supporting the inference that normal and strike-slip faulting took place during the late Middle or early Late Jurassic. We interpret these data to indicate that minor thrusting, probably during the Jurassic, was followed by extensional faulting within a strike-slip fault system, probably close in time to intrusion. These relations are similar to those reported previously in the nearby Newfoundland Mountains. Other mountains of northern Utah and adjacent Nevada also have examples of Jurassic normal faults that contrast with the more generally observed thrust faults and tectonite fabrics. These data point to a possible regional extensional tectonic event affecting the crust far inland of the Jurassic magmatic arc, an event probably associated with back-arc magmatism.

Coordination of Kinematic Events during Simple Arm Movements

This paper examines the pattern of kinematic events underlying repeated performance of simple rapid elbow flexion movements to a fixed target. The limb positions and time samples of kinematic indices are derived from forearm movement trajectories and measurements of the forces tangent to the arch described by the forearm during motion. The pattern of kinematic events are compared for different levels of the inertial load moved, distance traveled and target width. Results demonstrate that both time samples and limb positions corresponding to peak acceleration, peak velocity and peak deceleration varied significantly with inertial load and movement distance, but were relatively unaffected by changes in target width. Changes in the timing of kinematic events demonstrated no clear pattern across manipulations. Forearm positions, however, were highly proportional to the movement distance, with peak acceleration approximately 7% of the distance to the target, and peak velocity and deceleration approximately 47% and 87% of the distance to the target, respectively. These results are interpreted as indicating that the control processes governing the construction of motor commands are organized in terms of limb position instead of more traditional force-time representations. Mechanisms of this type are consistent with recent mass-spring models of muscle control.

Deformation mechanisms — recognition from natural tectonites

Deformation mechanisms which can operate in rocks include diffusive mass transfer, crystal plasticity, grain-boundary sliding as well as fracture and cataclasis. Each mechanism produces a range of characteristic deformation microstructures which help to constrain the conditions, dynamics and kinematics of tectonic events. Cyclic deformation events are particularly important to the development and preservation of microstructures. The review identifies four areas where future studies need to concentrate. The first is the identification of fracture mechanisms. The second is the detailed assessment of the characteristics and effects of cyclic deformation events or flow instabilities on deformation mechanism paths. The third is the need to quantify the microstructural stability of characteristic microstructures and the fourth is the need to incorporate analysis of PTt paths into the analysis of deformation mechanism paths.

Neck and shoulder motion of the gallop stride

The motion patterns of the neck and shoulders during the gallop stride were documented using high-speed cinematography. The gallop stride characteristics of 4 Quarter Horse fillies, approximately 30 months of age, were used as a model. Horses were housed and fed together and received the same amount and type of limited training; and were all ridden with the same tack and by the same person. Both sides of each horse were filmed simultaneously (243 frames/sec) while galloping individually along a 1.5-m-wide track. Kinematic variables describing 29 strides (mean velocity 13.1 m/sec, stride frequency 2.6 strides/sec, stride length 5.1 m) included linear and temporal measurements of the maximum and minimum heights of the wing of the atlas, spine of the scapula, shoulder joint and elbow joint; maximum and minimum angles with respect to the horizon of the neck, shoulder and arm segments; and maximum and minimum relative angles between the neck and shoulder, and shoulder and arm segments. Differences (P<.05) between the leading and trailing sides of the body were identified for 12 of a total of 27 spatial measurements reported for the neck, shoulder and arm, including minimum height of the scapula spine, maximum height of the scapula spine and elbow joint, maximum absolute angle of the shoulder segment, and minimum angle between neck and shoulder segments. Of 18 temporal measurements reported involving the neck, shoulder and arm, 14 differed (P<.05) between leading and trailing sides. Kinematic events describing the motion of the leading and trailing shoulder and arm segments were ordered and tabulated in the temporal sequence of the normal gallop stride. Results indicated that the motion patterns of the shoulder and arm segments were highly specific to the leading and trailing sides of the body in the equine gallop stride. The work required for vertical displacement of the center of mass in galloping was estimated to be approximately 98,500 J/km or 23.5 kcal/km; equivalent to approximately 6 percent of the total energy expenditure for galloping 1 km.

SPATIAL THINGS AND KINEMATIC EVENTS

SPATIAL THINGS AND KINEMATIC EVENTS

Temporal organization of muscle activity in simple disyllables

In an earlier paper, Tuller and her associates have shown that the onsets of consonant and vowel related activity in several articulatory muscles tend to maintain a constant relationship over changes in stress and speaking rate [Tuller et al., J. Exp. Psychol. Percept. Perf. 8, 460–472 (1982)]. Similar results are found for analogous kinematic events [Tuller et al., J. Exp. Psychol. Percept. Perf. 9, 829–833 (1983)]. The present study confirms and extends the results of the original electromyographic study, for a speaker of a different language (French rather than English), for a somewhat extended consonant and vowel inventory /p VC p a p/, where V = /i, a, or u/, and C = /p, t, s/; and for a somewhat broader range of muscles, five associated with tongue movement, and two others associated with lip and jaw movements. The constancy of the relative timing is compatible with a model of speech production in with coordinative structures are specified. [Research supported by NINCDS.]

Kinematic separations for three body final state reactions

Three body final state reactions at low energy in which two nonidentical charged particles are detected are complicated by kinematic interference in certain regions of the kinematic plane. Preliminary results are presented which indicate that a time-of-flight technique can be used to separate interfering kinematic events without the loss of any experimental information.

Optical Processing of Bubble Chamber Photographs

The processing of bubble chamber photographs has emerged as a major task in the experimental study of sub-atomic decays and interactions. Although electronic computer techniques have proved useful in reconstructing the geometry and ascertaining the kinematics of high-energy events, the scanning and measuring of bubble chamber photographs has remained for the most part unautomated. An alternate approach to the computerization of the scan-measure task is through the newly developed optical computer, a device which accepts input data on photographic film and thus obviates the need for digitizing photographs before processing. The optical computer can aid the scan-measure task by suppressing beam tracks, measuring track widths, and determining scattering angles.