• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.1-13
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• 2014

Apart from the physical realism, the implementation of various physical actions of an agent to respond to dynamically changing situations is essential for the design of an agent in a cyber world. To achieve a maximum diversity in actions, we develop a mechanism that allows composite actions to be constructed by reusing a set of primitive motions and enables an agent to instantly react to changes in the ambient states. Specifically we model an agent's body in terms of joints, and a primitive or composite motion is performed in a real time. To implement this mechanism, we produce an animation for basic joint movements and develop a method to construct overall motions out of the primitive motions. These motions can be assembled into a plan by which an agent can achieve a goal. In this manner, diverse actions can be implemented without excessive efforts. This approach has conspicuous advantages when constructing a parallel action, e.g., eating while walking, that is, two or more parallel actions can be naturally merged into a parallel action according to their priority. We implement several composite and parallel actions to demonstrate the viability of our approach.

• The Journal of Korean Physical Therapy
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• v.2 no.1
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• pp.35-46
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• 1990

The right hip adbuctor musculature has been reported to demonstrate 'stretch weakness' attributable to chronic elongation imposed by standing posture common to right-handed healthy persons. Kendall and associates have described the concept of 'stretch weakness'. The purpose of this study was to assess isometric hip abduction torque and surface electro-myographic activity (using MYOMED 432) in a sample of 40 healthy right-handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t-test was applied at the .05 level of significance. The results were as follows : 1. The difference in apparent leg length of right and left legs was significant at the .05 leve1. 2. There was a significant difference between right and left pelvic height (standing position) at the .005 level measurements, and scapula height at the .05 level. 3. Power measurements and action potentials of right hip adbuctor were greater than the left hip adbuctor regardless of the range of joint motion (inner range, outer range). 4. The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5. In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p<.005). These results suggest : In healthy right-handed persons. the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side. Muscle torque and muscle action potentials of the right hip adbuctor art higher than those of the hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall's. This type of study should be carried out in many physical therapy departments.

• Journal of the Korea Computer Graphics Society
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• v.27 no.5
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• pp.55-61
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• 2021

The character motion control based on physics simulation using reinforcement learning continue to being carried out. In order to solve a problem using reinforcement learning, the network structure, hyperparameter, state, action and reward must be properly set according to the problem. In many studies, various combinations of states, action and rewards have been defined and successfully applied to problems. Since there are various combinations in defining state, action and reward, many studies are conducted to analyze the effect of each element to find the optimal combination that improves learning performance. In this work, we analyzed the effect on reinforcement learning performance according to the state representation, which has not been so far. First we defined three coordinate systems: root attached frame, root aligned frame, and projected aligned frame. and then we analyze the effect of state representation by three coordinate systems on reinforcement learning. Second, we analyzed how it affects learning performance when various combinations of joint positions and angles for state.

• Journal of Music and Human Behavior
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• v.14 no.2
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• pp.19-43
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• 2017

This study aimed to examine the effects of a reciprocal attention intervention on the joint attention behaviors of children with autism spectrum disorder (ASD) by comparing the music and nonmusic conditions. An alternating treatment design was applied as one of the single subject designs and the reciprocal attention intervention included music and nonmusic conditions implemented alternately within a session. The participants were four children between the ages 4 and 5 years and each participant who participated in 23 intervention sessions that followed the sequence of baseline (3 sessions), treatment (15 sessions), and follow-up (5 sessions). The music condition consisted of structured joint instrument playing, trials for attentional shift, and interactive instrument playing. The nonmusic condition consisted of joint toy play, trials for attentional shift, and turn taking-based play. The occurrence of target behaviors (i. e., joint attention behavior, eye gaze, and joint action) was analyzed across sessions. At pretest and posttest, the Early Social Communication Scale was administered. All participants showed increasing tendency in all target behaviors, but such occurrence was greater in the music condition than in the nonmusic condition. The findings support the use of a reciprocal attention intervention with musical stimuli to effectively improve joint attention in this population.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.170-175
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• 2018

For the seismic performance, it is necessary to prevent the destruction of the expansion joint device due to the appropriate deformation of the expansion joint device due to the seismic force. Recently, the hinge is installed on the fingering of the expansion joint device in Korea, New products are being developed. In this paper, we have experimentally evaluated the real scale resistance of the expansion joints with rotational finger joints against load at right angle to the bridge axis. Experimental results show that the maximum horizontal displacement is about 21.1mm for conventional stretch joints and 51.00mm for seismic stretch joints. It is presumed that the existing expansion joint test specimen is resistant to the load in a direction perpendicular to the throat axis, and then the bending and shear deformation of the finger are excessively generated and the fracture phenomenon is likely to occur. On the other hand, in the case of the seismic expansion joint, the deformation of the load due to the load is absorbed by the hinge of the finger with respect to the load in the direction perpendicular to the throat, so that only horizontal deformation in the direction of load action.

• Steel and Composite Structures
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• v.21 no.5
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• pp.1017-1029
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• 2016

When a welded circular hollow section (CHS) tubular joint is subjected to brace axial loading, failure position is located usually at the weld toe on the chord surface due to the weak flexural stiffness of the thin-walled chord. The failure mode is local yielding or buckling in most cases for a tubular joint subjected to axial load at the brace end. Especially when a cyclic axial load is applied, fracture failure at the weld toe may occur because both high stress concentration and welding residual stress along the brace/chord intersection cause the material in this region to become brittle. To improve the ductility as well as to increase the static strength, a tubular joint can be reinforced by increasing the chord thickness locally near the brace/chord intersection. Both experimental investigation and finite element analysis have been carried out to study the hysteretic behaviour of the reinforced tubular joint. In the experimental study, the hysteretic performance of two full-scale circular tubular T-joints subjected to cyclic load in the axial direction of the brace was investigated. The two specimens include a reinforced specimen by increasing the wall thickness of the chord locally at the brace/chord intersection and a corresponding un-reinforced specimen. The hysteretic loops are obtained from the measured load-displacement curves. Based on the hysteretic curves, it is found that the reinforced specimen is more ductile than the un-reinforced one because no fracture failure is observed after experiencing similar loading cycles. The area enclosed by the hysteretic curves of the reinforced specimen is much bigger, which shows that more energy can be dissipated by the reinforced specimen to indicate the advantage of the reinforcing method in resisting seismic action. Additionally, finite element analysis is carried out to study the effect of the thickness and the length of the reinforced chord segment on the hysteretic behaviour of CHS tubular T-joints. The optimized reinforcing method is recommended for design purposes.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.235-244
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• 2016

This study was conducted to verify seismic performance of special moment frame's joints at roof-level with high-strength concrete and SD600 bars. K-RC-H was designed according to the seismic code and K-HPFRC-H had 150% of the original hoop spacing and 1.0% steel fiber volume fraction compared with K-RC-H. Both specimens had remarkable seismic performance without noticeable decrease in moment, but with very good energy dissipation before rebar failure. The U-bars in the joint sufficiently constrained rebar's action that pushed the cover upward. SD600 bars with $1.25l_{dt}$ had minimum slip in the joint. It was considered that the steel fiber contributed to improvement of the bending moment and joint shear distortion, and the result showed that it would be possible to increase the hoop spacing to 150% of the regular spacing.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.1
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• pp.55-61
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• 2017

Recently several researches have been conducted to develop sliding track system in which friction between concrete track and bridge slab has been reduced. This paper investigated shear load carrying capacity of lateral supporting concrete block which should be implemented to resist lateral load due to train in sliding track system. In order to evaluate shear load carrying capacity of lateral supporting concrete block, analytical model has been developed considering concrete friction and rebar dowel action along construction joint. The proposed model predicted test results on the shear load carrying capacity from literature conservatively by 13~23% because effect of aggregate interlock along crack surface was neglected. Since construction joint status is ambiguous on construction site, it can be concluded that the proposed model can be used for reasonable design of lateral supporting concrete block. Based on the proposed model, design proposal for lateral supporting concrete block has been established.

• Journal of Korean Society of Steel Construction
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• v.21 no.6
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• pp.647-657
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• 2009

This paper studies the behavior of joints in steel-PSC (prestressed concrete) hybrid beams, which is necessary for the application of hybrid beams to spliced girder bridges, and proposes a new type of joint with improved construction convenience and structural behavior. In the proposed joint, perfobond rib shear connectors are attached to the upper and lower plates, which are expanded from the steel girders and located between the steel girder and the PSC girder. The experimental tests were performed on hybrid beams with the suggested joint. The results showed that all the beams had similar ultimate strengths and failure modes, due to the failure of their PSC parts. The composite action of the perfobond ribs was verified by examining the initial stiffness and cracks of the test beams. In addition, the test beams showed a higher degree of ultimate strength than the beams with stud shear connectors in the joints that had been previously studied. Thus, the proposed joint is effective for the steel-PSC hybrid beam.

• The Journal of Dong Guk Oriental Medicine
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• v.5
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• pp.79-95
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• 1996

When we see normal gait, gait cycle is seperated as stance phase and swing phase. It needs 6 determinant of gait of pelvic rotation, pelvic tilt, knee joint of stance phase, ankle and foot motion, ankle and knee motion, and pelvic movement to be accomplished. In addition, a joint and muscle action is accomplished biomechanically at the same time with its gait cycle. In oriental medicine, the relationships between chang-fu physiology and meridian physiology are summaried as follows ; ${\bullet}$ chang-fu physiology : Spleen manages the extremities. Liver manages soft tissues. Liver stores blood. Kidney stores essences. Kidney manages bones. ${\bullet}$ meridian physiology : The Leg Greater Yang Meridian and meridian soft tissues The Leg Yang-Myeong Meridian and meridian soft tissues The Leg Lesser Yang Meridian and meridian soft tissues The Leg Greater Yin Meridian and meridian soft tissues The Leg Lesser Yin Meridian and meridian soft tissues The Leg Absolute Yin Meridian and meridian soft tissues Especially, we can find out relations between in a "blood supplied feet can walk well" that explains "blood regulations and by liver nourishing effects"that is the closest concept of muscle. Abnormal gaits are due to three causes as following; first, physical defect secoud, pain third, nervous system or instability of muscle. In oriental medicine, we can know relationship in "atrophy, numbness, stroke, convulsion, muscular dystrophy of knee, rheumatoid arthritis, five causes of infantile growing defects, five causes of softening, sprain". Especially, atrophy is the most important symptom. Gait evaluation should be emphasized where a point can walk 8 feet to 10 feet considering stride width, stride length, the body weight center, stride number, flexion, extension, rotation of a joint as a standard factor. The point is we should find out something strange in a patient's side, front and back view. After that we should find out its cause as an index that we can observe abnormal findings in a joint and muscle.