scholarly journals Gauge link structure in quark–quark correlators in hard processes

2004 ◽  
Vol 596 (3-4) ◽  
pp. 277-286 ◽  
Author(s):  
C.J. Bomhof ◽  
P.J. Mulders ◽  
F. Pijlman
Keyword(s):  
Gauge Link ◽  
Link Structure

scholarly journals FINAL STATE INTERACTIONS AND THE TRANSVERSE STRUCTURE OF PION

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2960-2972 ◽  
Author(s):  
LEONARD GAMBERG ◽  
MARC SCHLEGEL
Keyword(s):  
Time Reversal ◽  
Final State Interaction ◽  
Final State ◽  
Parton Distributions ◽  
Spatial Distortion ◽  
Transverse Structure ◽  
Gauge Link ◽  
Link Structure ◽  
Final State Interactions ◽  
Mulders Function

In the factorized picture of semi-inclusive deep inelastic scattering the naive time reversal-odd parton distributions exist by virtue of the gauge link which is intrinsic to their definition. The link structure describes initial/final-state interactions of the active parton due to soft gluon exchanges with the target remnant. Though these interactions are non-perturbative, calculations of final-state interaction have been performed in a perturbative one-gluon approximation. We include higher-order contributions by applying non-perturbative eikonal methods to calculate the Boer-Mulders function of the pion. Using this framework we explore under what conditions the Boer Mulders function can be described in terms of factorization of final state interactions and a spatial distortion.

scholarly journals Barrier-Free Wheelchair with a Mechanical Transmission

2021 ◽  
Vol 11 (11) ◽  
pp. 5280
Author(s):  
Jongseok Lee ◽  
Wonhyeong Jeong ◽  
Jaeoh Han ◽  
Taesu Kim ◽  
Sehoon Oh
Keyword(s):  
The Elderly ◽  
Transmission System ◽  
Motor Drives ◽  
Mechanical Transmission ◽  
Link Structure ◽  
Second Mode ◽  
Important Means ◽  
The Stability ◽  
Flat Ground ◽  
Climbing Stairs

Wheelchairs are an important means of transportation for the elderly and disabled. However, the movement of wheelchairs on long curbs and stairs is restricted. In this study, a wheelchair for climbing stairs was developed based on a mechanical transmission system that rotates the entire driving part through a link structure and an actuator to change the speed. The first mode drives the caterpillar, and the second mode drives the wheels. When driving on flat ground, it uses landing gears and wheels, and when climbing stairs, it uses the caterpillar; accordingly, a stable driving is possible. The stability of the transmission is confirmed through stress analysis. The method used in our study makes it is possible to manufacture lightweight wheelchairs because a single motor drives both the wheel and caterpillar through the transmission system.

Mechanism Design and Simulation of the ULTRA Spine: A Tensegrity Robot

2015 ◽  
Author(s):  
Andrew P. Sabelhaus ◽  
Hao Ji ◽  
Patrick Hylton ◽  
Yakshu Madaan ◽  
ChanWoo Yang ◽  
...  
Keyword(s):  
Mechanism Design ◽  
Design Process ◽  
Inverse Kinematics ◽  
Gear Ratio ◽  
Forward Kinematics ◽  
Robot Design ◽  
Link Structure ◽  
Iterative Design ◽  
Quadruped Robots ◽  
Ongoing Effort

The Underactuated Lightweight Tensegrity Robotic Assistive Spine (ULTRA Spine) project is an ongoing effort to create a compliant, cable-driven, 3-degree-of-freedom, underactuated tensegrity core for quadruped robots. This work presents simulations and preliminary mechanism designs of that robot. Design goals and the iterative design process for an ULTRA Spine prototype are discussed. Inverse kinematics simulations are used to develop engineering characteristics for the robot, and forward kinematics simulations are used to verify these parameters. Then, multiple novel mechanism designs are presented that address challenges for this structure, in the context of design for prototyping and assembly. These include the spine robot’s multiple-gear-ratio actuators, spine link structure, spine link assembly locks, and the multiple-spring cable compliance system.

Color Entanglement in Hadronic Processes for Transverse Momentum Dependent Parton Distribution Functions

2015 ◽  
Vol 37 ◽  
pp. 1560022
Author(s):  
M. G. A. Buffing ◽  
P. J. Mulders
Keyword(s):  
Transverse Momentum ◽  
Parton Distribution ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Initial State ◽  
Color Flow ◽  
Transverse Momentum Dependent ◽  
Gauge Link ◽  
Azimuthal Asymmetries ◽  
Different Parts

In the description of protons, we go beyond the ordinary collinear parton distribution functions (PDFs), by including transverse momentum dependent PDFs (TMDs). As such, we become sensitive to polarization modes of the partons and protons that one cannot probe without accounting for transverse momenta of partons, in particular when looking at azimuthal asymmetries. Hadronic processes require the inclusion of gluon contributions forming the gauge links, which are path-ordered exponentials tracing the color flow. In processes with two hadrons in the initial state, such as Drell-Yan (DY), the gauge links from different parts of the process get entangled. We show that in color disentangling this gauge link structure, one becomes sensitive to this color flow. After disentanglement, particular combinations of TMDs will require a different numerical color factor than one naively might have expected. Such color factors will even play a role for azimuthal asymmetries in the simplest hadronic processes such as DY.

scholarly journals Personal Life, Pragmatism and Bricolage

2011 ◽  
Vol 16 (4) ◽  
pp. 129-140 ◽  
Author(s):  
Simon Duncan
Keyword(s):  
Social Norms ◽  
Empirical Research ◽  
Social Relationships ◽  
Social Groups ◽  
Social World ◽  
Personal Life ◽  
Personal Lives ◽  
Link Structure ◽  
Structure And Agency ◽  
Social Legitimation

Individualisation theory misrepresents and romanticises the nature of agency as a primarily discursive and reflexive process where people freely create their personal lives in an open social world divorced from tradition. But empirically we find that people usually make decisions about their personal lives pragmatically, bounded by circumstances and in connection with other people, not only relationally but also institutionally. This pragmatism is often non-reflexive, habitual and routinised, even unconscious. Agents draw on existing traditions - styles of thinking, sanctioned social relationships, institutions, the presumptions of particular social groups and places, lived law and social norms - to ‘patch’ or ‘piece together' responses to changing situations. Often it is institutions that ‘do the thinking’. People try to both conserve social energy and seek social legitimation in this adaption process, a process which can lead to a ‘re-serving' of tradition even as institutional leakage transfers meanings from past to present, and vice versa. But this process of bricolage will always be socially contested and socially uneven. In this way bricolage describes how people actually link structure and agency through their actions, and can provide a framework for empirical research on doing family.

scholarly journals LINK STRUCTURE AND TRIBOLOGICAL PROPERTIES OF ZINC DIALKILDITHIOPHOSPHATES

2016 ◽  
Vol 16 (04) ◽  
pp. 67-74
Author(s):  
I. V. Mukhortov ◽  
◽  
K. A. Pachkaylo ◽  
A. A. Doykin ◽  
I. G. Levanov ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Link Structure
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