• Physical Therapy Korea
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• v.28 no.1
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• pp.47-52
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• 2021

Background: Compared with normal people, stroke patients have decreased voluntary craniocervical motion, which affects their balance. Objects: This study was conducted in order to examine the effects of active craniocervical movement training using a cognitive game on stroke patient's cervical movement control ability, balance, and functional mobility. Methods: The subject of this study were 29chronic stroke patients who were randomly allocated to either an experimental, cognitive game group (n = 15), or control group (n = 14), to which only neuro-developmental treatment (NDT) was applied. The intervention was conducted 5 times per week, 30 minutes per each time, for a total of 4 weeks. Active angle reproduction test, static stability test, limits of stability test, and Time up and Go (TUG) test, respectively, were carried out in order to evaluate cervical movement control ability, static balance, dynamic balance, and functional mobility. Paired t-test was used in order to compare differences between prior to after the intervention, along with an independent-test in order to compare prior to and after-intervention differences between the two groups. Results: After the craniocervical training with a body-driven cognitive game, the experimental group showed significant differences in flexion, extension, and lateral flexion on the affected side, and rotation on the affected side in the active angle reproduction test. The experimental group indicated significant differences in sway length both with eyes-open and with eyesclosed in the static stability test and in limits of stability test and TUG test. The control group to which NDT was applied had significant differences in flexion in the active angle reproduction test and in limits of stability test and TUG test. Conclusion: The above results mean that craniocervical training using a body-driven cognitive game positively influences stroke patient's cervical movement control ability and as a result their balance and functional mobility.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.242-247
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• 2022

Purpose: This study investigates the effect of 60° semi-squat exercises according to three different types of support surfaces. The effects were examined on joint position sense and balancing ability using stable and unstable surfaces in patients afflicted with post-stroke hemiplegia. Methods: Subjects were instructed to perform three sets of 60° semi-squat exercises according to the characteristics of the support surface conditions. The three ground states were bilateral stable surface (BSS), nonaffected side unstable surface (NUS), and bilateral unstable surface (BUS). The joint position sense, characteristics of body sway, and dynamic balance were analyzed according to floor conditions before and after the experiment. A balance-pad (50 cm W×41 cm L×6 cm H; Alcan Airex AG, Sins, Switzerland) was used for the unstable floor. Results: The 60° semi-squat exercises applied to hemiplegic patients showed the highest statistical significance in joint position sense in the NUS group, and Timed Up and Go test (TUG) in the BUS group (p<0.05). Conclusion: Functional training using an unstable surface can be applied as a meaningful intervention method for improving the balance and joint position sense of stroke patients.

• Physical Therapy Korea
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• v.7 no.2
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• pp.1-19
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• 2000

Decreased equilibrium in standing and walking is a common problem associated with hemiparesis secondary to cerebral vascular accident. In patients with hemiplegia, postural sway is increased and often displaced laterally over the non-affected leg, reflecting asymmetry in lower extremity weight bearing during standing balance. Human balance is a complex motor control task, requiring integration of sensory information, neural processing, and biomechanical factors. Limits of stability (LOS) is a one of the biomechanical factors. The purposes of this study were to establish the influence of asymmetrical weight-bearing on the LOS of independent ambulatory hemiparetic patients. The subjects of this study were 29 hemiparetic patients (18 males, 11 females) being treated as admitted or out patients at Young-Nam University Hospital and Taegu Catholic University Hospital, all of whom agreed to participate in the study. Participants were asked to lean and displace their center of gravity (COG) as far as possible in directions to the sides and front of the body. The LOS and weight-bearing ratio were measured with a Balance Performance Monitor (BPM) Dataprint Software Version 5.3. In order to assure the statistical significance of the results, the independent t-test and a Pearson's correlation were applied at the .05 and .01 level of significance. The results of this study were as follows: 1) There were statistically significant differences in anteroposterior LOS according to the cause of brain demage (p<.01). 2) There were statistically significant differences in mediolateral LOS according to the hemiparetic side (p<.05). 3) There were statistically significant differences in anteroposterior and mediolateral LOS according to the brain operation (p<.01). 4) The mediolateral LOS significantly correlated with weight-bearing ratio (p<.01).

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.1
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• pp.3-12
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• 1984

Up to now, it has been common to treat the maneuvering motion of a ship as a 3-degree-freedom motion i.e. surge, sway and yaw on the sea surface, for the simplicity and mathematical calculation, and it is quite acceptable in the practical point of view. Meanwhile, considering the maneuverability of a ship under the special conditions such as in irregular waves, in wind or at high speed with small GM value, it is required that roll effect must be considered in the equation of ship motion. In this paper the author tried to build up the 4-degree-freedom motion equation by adding roll. And then, applying the M.M.G.'s mathematical model and with captive model test results the roll-coupled hydrodynamic derivatives were found. With these the author could make some simulating program for turning and zig-zag steering. Through the computer simulations, the effect of roll to the ship maneuver became clear. The effect of the wind force to the maneuverability was also found. Followings are such items that was found. 1) When roll is coupled in the maneuvering motion, the directional stability becomes worse and the turning diameter becomes smaller as roll becomes smaller as roll becomes larger. 2) When maneuver a ship in the wind, the roll becomes severe and the directional stability becomes worse. 3) When a ship turns to the starboard side, the wind blowing from 90 degree direction to starboard causes the largest roll and the largest turning diameter, and the wind from other direction doesn't change the turning diameter. 4) When a ship is travelling with a constant speed with rudder amidship, if steady wind blows from one direction, the ship turns toward that wind. This phenomenon is observed in the actual seaways.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.71-78
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• 2010

Rapid urbanization causes a variety of transportation problems, including traffic delay. Then transportation engineers would get involved in trying to solve traffic delay through road constructed and uncongested policy. But lately, traffic policy changed from vehicle-dominated to humandominated and green transportation. Road diet is one of green transportation. Road diets reduce the number of lanes, lane width because supplement space for green transportation including a bicycle road, side-walk, etc. A study on road diets not enough then this study performed a basic study for road diets. This study on lane width reduce for road diets through analyzes sway of moving vehicle. This study results shows lane width of a compacts-size car needs 2.34~2.70m and lane width of a full-size car needs 2.62~2.89m. According to this study lane width can reduce therefore lane width design criterion have to be relieved. This study will be used in a road width reduce including a road diets, road in process of construction and so on.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.115-126
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• 2016

Objective: The purpose of this study was to investigate plantar foot pressure and static balance according to the type of insole in the elderly. Methods: Thirteen elderly (mean age: $67.08{\pm}2.25years$, mean height: $159.63{\pm}9.64cm$, mean body weight: $61.48{\pm}9.06kg$) who had no previous injury experience in the lower limbs and a normal gait pattern participated in this study. Three models of insoles of the normal, 3D, and triangle types were selected for the test. The Pedar-X system and Pedar-X insoles, 3.3 km/h of walking speed, and a compilation of 20 steps walking stages were used to analyze foot-pressure distribution. Static balance test was conducted using Gaitview AFA-50, and balance (opening eyes, closing eyes) was inspected for 20 s. One-way ANOVA was conducted to test the significance of the results with the three insoles. p-value of less than .05 was considered statistically significant. Results: The mean foot pressure under the forefoot regions was the lowest with the 3D insole during treadmill walking (p<.05). The mean value under the midfoot was the highest with the 3D insole (left: p<.05, right: p<.01). The mean value under the rearfoot was the lowest with the 3D insole (p<.001). The maximum foot pressure value under the foot regions was the lowest on both sides of the forefoot with the 3D insole. A statistically significant difference was seen only in the left foot (p<.01). The maximum value under the midfoot was the highest with the 3D insole (p<.001). No statistically significant difference was detected on the values under the rearfoot. In the case of vertical ground reaction force (GRF), statistically significant difference was seen only in the left side rearfoot (p<.01). However, static balance values (ENV, REC, RMS, Total Length, Sway velocity, and Length/ENV) did not show significant differences by the type of insole. Conclusion: These results show that functional insoles can decrease plantar pressure and GRF under the forefoot and rearfoot. Moreover, functional insoles can dislodge the overload of the rearfoot and forefoot to the midfoot. However, functional insoles do not affect the static balance in the elderly.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.889-901
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• 2021

The tension of cables and motion response significantly affect safety of an immersed tunnel element in the immersion process. To investigate those, a hydrodynamic scale-model test was carried out and the model experiments was conducted under wind, current and wave loads simultaneously. The immersion standby (the process that the position of the immersed tunnel element should be located before the immersion process) and immersion process conditions have been conducted and illustrated. At the immersion standby conditions, the maximum force of the cables and motion is much larger at the side of incoming wind, wave and current, the maximum force of Element-6 (6 cables directly tie on the element) is larger than for Pontoon-8 (8 cables tie on pontoon of the element), and the flexible connection can reduce the maximum force of the mooring cables and motion of element (i.e. sway is expecting to decrease approximate 40%). The maximum force of the mooring cables increases with the increase of current speed, wave height, and water depth. The motion of immersed tunnel element increases with increase of wave height and water depth, and the current speed had little effect on it. At the immersion process condition, the maximum force of the cables decrease with the increase of immersion depth, and dramatically increase with the increase of wave height (i.e. the tension of cable F4 of pontoons at wave height of 1.5 m (83.3t) is approximately four times that at wave height of 0.8 m). The current speed has no much effect on the maximum force of the cables. The weight has little effect on the maximum force of the mooring cables, and the maximum force of hoisting cables increase with the increase of weight. The maximum value of six-freedom motion amplitude of the immersed tunnel element decreases with the increase of immersion depth, increase with the increase of current speed and wave height (i.e. the roll motion at wave height of 1.5 m is two times that at wave height of 0.8 m). The weight has little effect on the maximum motion amplitude of the immersed tunnel element. The results are significant for the immersion safety of element in engineering practical construction process.