• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1135-1142
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• 2017

The applicability of the algebraic collapsing acceleration (ACA) technique to the method of characteristics (MOC) in cases with scattering anisotropy and/or linear sources was investigated. Previously, the ACA was proven successful in cases with isotropic scattering and uniform (step) sources. A presentation is first made of the MOC implementation, available in the DRAGON5 code. Two categories of schemes are available for integrating the propagation equations: (1) the first category is based on exact integration and leads to the classical step characteristics (SC) and linear discontinuous characteristics (LDC) schemes and (2) the second category leads to diamond differencing schemes of various orders in space. The acceleration of these MOC schemes using a combination of the generalized minimal residual [GMRES(m)] method preconditioned with the ACA technique was focused on. Numerical results are provided for a two-dimensional (2D) eight-symmetry pressurized water reactor (PWR) assembly mockup in the context of the DRAGON5 code.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.83-86
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• 1999

We have fabricated $_2Cu_3O_7$ step-edge junctions with different step orientations and studied their transition properties. Steps with different orientations were prepared on the substrate. Josephson junctions were made on a single substrate with step orientations ranging from 0$^{\circ}$ to 165$^{\circ}$ at 15$^{\circ}$ interval. We measured current-voltage characteristics, the critical current, and the superconducting transition temperature as a function of the angle. The critical current showed a modulation that has a maximum near 0$^{\circ}$ or 90$^{\circ}$ and a minimum near 45$^{\circ}$ and 135$^{\circ}$. We believe that the critical current modulation with the step orientation could be associated with the symmetry of high T$_c$ superconductor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2187-2196
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• 2011

The objective of this study was to investigate the effect of gait training using rhythmic auditory stimulation on gait symmetry of stroke patients. Forty chronic stroke patients were divided into four groups by intervention. Group A and B received auditory stimulation when they walk with comfortable gait speed. Group A received auditory stimulation to paralyzed side while group B to non-paralyzed side. Group C and D received auditory stimulation with 10% faster gait speed than their comfortable gait speed. Group C received auditory stimulation to paralyzed side while group D to non-paralyzed side. Gait training using auditory stimulation was done in each group during five minutes. Gait symmetry was evaluated by formula and temporal variables of gait were measured by gait analysis system. Step time was decreased significantly in all groups except group A (P<.05), and gait symmetry was also improved significantly in all groups except group A (P<.05). Cadence was increased significantly in all groups except group A (p<.05), but velocity was not increased in all groups. Therefore we conclude that RAS gait training is effective in improving gait symmetry and can be useful to stroke patient's gait training.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.04a
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• pp.57-64
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• 1994

The purpose of this paper is to find minimum surface shape of pneumatic structure using the finite element method. The pneumatic membrane structure is a kind of large deformation problem and very flexible composite material, which mean geomatric nonlinearity. It is not to resist for compression and resultant moment. As the displacement due to internal pressure is getting bigger, it should be considered the direction of forces. It becomes non-linear problem with the non-conservative force. The follower-force depends on the deformation and the direction of force is normal to each element. The solution process is obtained the new stiffness matrix (load correction matrix) depending on deformation through each iterated step. However, the stiffness matrix have not the symmetry and influence on the time of covergence. So in this paper Newton-Rhapson method for solving non-linear problem and for using symmetic matrix, the load direction is changed in each iterated step using the transformation matrix.

• 연구논문집
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• s.26
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• pp.15-24
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• 1996

In this study, we performed the static analysis of a cord-reinforced rubber airspring and generated the three-dimensional half-symmetry model which use the finite-strain shell elements to model the airbag. the three-dimensional hydrostatic fluid elements to model the air-filled cavity, and the rebar elements to model the multi-ply nylon reinforcement of airbag. In addition, a three-dimensional rigid surface is used to define the contact between the airspring and metal bead. The air inside the airspring cavity has been modeled as a compressible fluid satisfying the ideal gas law. The conclusions of this study are as follows. 1) In the pressurization step of analysis, we could predict the change of vertical reaction force, cavity volume and pressure within the airspring. 2) In the second step of analyzing vertical static stiffness, the increase of the vertical load increases the vertical stiffness. 3) In case of changing the angle of nylon cord, the increase the angle of nylon cord increases the vertical stiffness.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.189-196
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• 2013

This paper presents a two-stage approach to detect pedestrians in video sequences taken from a moving vehicle. The first stage is a preprocessing step, in which potential pedestrians are hypothesized. During the preprocessing step, a difference image is constructed using a global motion estimation, vertical and horizontal edge maps are extracted, and the color difference between the road and pedestrians are determined to create candidate regions where pedestrians may be present. The candidate regions are refined further using the vertical edge symmetry features of the pedestrians' legs. In the next stage, each hypothesis is verified using the integral channel features and an AdaBoost classifier. In this stage, a decision is made as to whether or not each candidate region contains a pedestrian. The proposed algorithm was tested on a range of dataset images and showed good performance.

• Journal of Korean Physical Therapy Science
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• v.15 no.3
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• pp.73-79
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• 2008

Background : Treadmill training has been proposed as a useful adjunct to conventional physical therapy to restore ability to walk after stroke. The purpose of this study to inform clinical practise by evaluating the research evidence for the effectiveness of treadmill training after stroke. Methods : We searched to the effectiveness of any form of intervention for effect of treadmill training by Dankook University electronic library databases of Medline, Embase, Cinahl, Amed and PEDro combined with a hand search of papers published in relevant peer-reviewed journals. Any type of study relevant to the topic published in English during time period from 1980 to 2007 was included. Results : The literature search identified 35 studies. The included studies enrolled a total of 374 subjects. 1. Treadmill retraining without partial body weight support might be more effective than no treatment at improving gait velocity, get up and go time, gait endurance and step length symmetry. 2. Treadmill retraining with partial body weight support might be more effective than no treatment in improving step length symmetry, gait velocity, gait endurance and balance. 3. Treadmill retraining might be more effective with partial body weight support than without it at improving gait velocity and motor improvement as measured by The Stroke Rehabilitation Assessment of Movement(STREAM). 4. Treadmill retraining without partial body weight support may be no different from physiotherapy and increase gait velocity to conventional gait therapy. 5. Treadmill retraining with partial body weight support may be no different from physiotherapy for gait velocity, motor recovery and balance. Conclusion The review suggests that although treadmill training of gait, especially with partial body weight support, might Improve gait parameters and functional mobility, unless treadmill training is directed at Improving gait speed it might be no more effective than conventional physical therapy at improving gait parameters.

• The Journal of the Society of Stroke on Korean Medicine
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• v.14 no.1
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• pp.80-89
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• 2013

■ Objectives The aim of study is to analyze the change of gait pattern by arm sling in a hemiplegic patient. ■ Methods We analyzed the change of gait pattern under three conditions using Treadmill Gait analysis equipment(Zebris Co.Ltd FDM-T) First, the patient didn't have arm sling on her upper limb, second, the patient have arm sling on her affected upper limb, third, patient have arm sling on her unaffected upper limb. ■ Results In terms of spatiotemporal gait values, swing phase, step time, step length of unaffected lower limb increased. Furthermore, stride time and stride length also increased when the patient had arm sling on her unaffected upper limb. In terms of displacement of Center of pressure(CoP), anterior/posterior position and lateral symmetry of CoP increased. Furthermore, lateral symmetry of decreased when the patient had arm sling on her affected upper limb. ■ Conclusion Arm sling applied on affected side would be advantage to gait improvement in hemiplegic patients.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.145-151
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• 2022

Purpose : Stroke patients exhibit abnormal walking patterns such as slow walking speed and asymmetrical walking values. The recovery of symmetrical walking in the stance phase using a treadmill means improvements in walking speed and asymmetrical walking. The purpose of this research was to investigate the effect of unilateral step treadmill training (USTT) on gait speed and the recovery of symmetrical walking in chronic stroke patients. Methods : Fifteen patients (11 men and 4 women) with chronic stroke participated in this study. The 10-meter walk test (10MWT) and GAITRite system were used to determine the intervention-related changes in gait speed and symmetrical walking values such as non-paretic step length (NSL), non-paretic step time (NST), paretic single-support time (PSST), step length asymmetry (SLA), and step time asymmetry (STA) after USTT. All participants completed USTT and underwent measurements at 3 different times: at pretest, posttest, and the follow-up test. Repeated-measures analysis of variance was used to compare walking speed and asymmetrical walking values. The statistical significance level was set at p<.05. Results : Walking speed by 10MWT (p<.05) showed significant improvements after USTT as follows: at pretest and posttest (p<.05), posttest and follow-up test (p<.05), and pretest and follow-up test (p<.05). Recovery of symmetrical walking patterns such as NSL (p<.05), NST (p<.05), and SLA (p<.05) were observed after USTT. However, no significant improvements were found in PSST (p>.05) and STA (p>.05) in symmetrical gait. Conclusion : This study suggests that USTT may have a positive effect on walking speed and symmetrical walking patterns in chronic stroke patients. Thus, this study contributes to the existing knowledge about the usefulness of USTT for the effective management of patients with chronic stroke. Further studies are needed to generalize these findings.

• Physical Therapy Korea
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• v.19 no.3
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• pp.81-90
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• 2012

The aim of the current study was to assess the effectiveness of backward gait training on the treadmill in patients with spastic diplegic cerebral palsy (CP). Twelve patients with spastic diplegic CP participated in the study. An 8-week course of backward gait training was administered to the subjects for 3 days per week. Pre-intervention and post-intervention assessments of temporal-spatial gait parameters, the symmetry of the bilateral lower extremity weight bearing, and gross motor function were analyzed using motion analysis system, force plate, and Gross Motor Function Measurement (GMFM). There were significant improvements (p<.05) in the measures of both step length and right stance phase time. Joint kinematics showed increase in right hip abduction in initial contact and terminal swing, right hip external rotation and knee flexion in mid-swing, left ankle dorsiflexion in initial contact and terminal swing (p<.05). The symmetry of the bilateral lower extremity weight bearing and GMFM also significantly increased (p<.05). These findings indicate that backward gait training using a treadmill is beneficial for patients with spastic diplegic CP.