• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.585-592
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• 2005

In this paper, we present the principle of virtual work, from which the exact non-linear equations of motion of a rotating ring can be derived, by using the theory of finite deformation For a thin ring of which the effect of variation in curvature across the cross-section is neglected, the radial displacement and the extensional stress are determined from the principle of virtual work at the steady state where the ring is rotating with a constant angular velocity. And also we formulate systematically the governing equations concerned to the in-plane vibrations and the out-of-plane vibrations at the disturbed state by using the principle of virtual work which is expressed with the disturbed displacements about the steady state. The formulated governing equations are classified by four models along the cases of considering or neglecting all or partly the secondary effects of flexural shear, rotary inertia, circumferential extension, and twist inertia. The natural vibrations of thin rings are analyzed, and its results are compared and discussed.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.897-904
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• 2008

The major objective of this study is to investigate the effective improvement plan for the curve sections in the conventional lines which the tilting train runs on. In order to the speed-up of conventional lines that have many curve lines, there needs a improvement construction of substructure such as the straight or double track work and so on. But in this case, it needs to have a plenty of the cost and the period. Therefore, the tilting train which provides the high-speed service effectively in curve tracks and is operating at abroad, was been studying to be suited to natural features. So, in this paper we investigate the improvement method at the sections only where need the extension of the transition curves, and the present status of them for the effective tiling train service using results which were examined on the preceding study which was the development of track system innovation technology for speed-up of them. And we look forward to playing a decisive role as reference material for the decision of the linear fitness in order to operate effectively on the conventional lines for the commercial service of the tilting train, on the basis of checking out the sufficient condition concerned in the track alignment and the velocity which are required in the railway construction rules and the design criteria.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.161-168
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• 2019

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.156-163
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• 1995

An experimental protocol was developed and tested in this study in order to quantify the motor control capability of the trunk movement for both healthy subjects and low-back pain (LBP) patients. Information processing capacity (bits/second) (Fitts, 1954) and dynamic motor perfor- mance such as flexion/extension velocity and acceleration were measured as motor control parameters under the controlled range of motion (ROM). In this study, the original experimental propocol (Kim et al., 1993, 1994) was re-designed to reduce the length of the test via a series of statistical analyses for clinical application. The accuracy of the shortened protocol was statistically examined and indicated no difference conpared to the original protocol in terms of evaluating information processing capacity. This protocol was also tested among ten healthy subjects and ten LBP patients for validation purpose. The results showed that the information processing capacity was not significantly diffenent between two groups due to the large variation although there was an apparent mean difference. Average movement time showed a significant increase in LBP patients com- pared to healthy subjects. In conclusion, it was found that the new short experimental protocol could quantify the motor control capability of neuromuscular system of the trunk and also showed the applicability to patient population.

• Korean Journal of Applied Biomechanics
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• v.14 no.1
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• pp.117-131
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• 2004

The foreign superior players and national team players' turning phase was measured, compared and analyzed to help the representative players improve the skill of turn. The underwater video camera used to analyze and evaluate the representative players' skill of turn in detail and the result is as follows. 1. The record for the phase of turn was similar to the rank of the last record. The improvement of the skill of turn was required because Korean players' record was lower than the foreign players' one. In case of 200m events the 1st turn was the fastest and it took more time as the turn is repeated. 2. It shows that the preparation phase and turing motion cause the difference between the players and within one player. 3. The horizontal movement of center of gravity moves to turning point slowly in the preparation phase, does not move nearly in the turning phase and increase again in the propulsion phase. Good record has short time for turn phase. The result means that the shorten the turning phase is the most important factor. Therefore the preparation for this is required. The vertical movement is maintained or increase a little and then move to from the turning phase. 4. The characteristic of horizontal velocity in center of gravity is that there is any big changes at the preparation phase, the faster velocity is found from the better record and the accelerating time is fast at the propulsion phasen. The wrong motion is made by not using the swimming velocity for fuming and waiting and more time is required by this. 5. The angle of knee when the player touch the turning point is 106.22-135.56 and the maximum angle of knee during the driving after the touch of tuning point is full extension. The size of maximum angle of knee did not match with the required time of propulsion phase. It seems that the individual difference is big when the players touch the turning point the angle of knee and the research for the individual angle which can reveal the maximum power should be carried out. The national team player's skill for the him is behind the foreign players' one and a lot of problems were found. It shows that the players could not practice the skill for turn during the training. The 1st reason for it is the various facilities like underwater window or analyzing equipment like underwater camera with which the coaches can teach and correct the players' detailed skill. It is need to evaluate the players' detailed skill exactly and correct it by objective data to complete the good skill in the future. In this regard, the investment for the facility is necessary.

• Journal of Korean Academy of Nursing
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• v.26 no.3
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• pp.556-575
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• 1996

In an attempt to investigate the effect of a muscle strengthening exercise program on muscle strength, pain, depression, self-efficacy and quality of life of patients with knee osteoarthritis, a pre-experiment, one group pre-test & post-test design, was planned. Muscle strengthening exercise was carried out from May 22 through August 14, 1995 at isokinetic exercise room in rehabilitation department of University Hospital in Taejon. The subjects were seven female clients conveniently sampled from University Hospital located in Taejon, between 39 and 61 years of age, who had a osteoarthritis in knee. Muscle strengthening exercise program was composed of three sessions per week, one isokinetic exercise at angular velocity of 60° and 180° with Cybex isokinetic dynamometer and two resistance home exercise sessions with elastic band. Data were analyzed with frequency, percentage of change, Friedman test, Duncan test using SAS program. Results were obtained as follows : 1) Flexion and extension muscle strength at angular velocity of 60° and 180° were increased after 12weeks' exercise than those of before experiment. But exept flexion muscle strength at angular velocity of 180°(F=3.34, P=0.0261), there was no statistically significant difference among muscle strengths, which is measured every 3 weeks. 2) Pain was decreased after 6weeks' exercise than that of before experiment, and after 12weeks' exercise than that of 6weeks' exercise. There was statistically significant difference (F=4.28, P=0.0396). 3) Depression was increased after 6weeks' exercise than that of before experiment, and after 12weeks' execise than that of 6weeks' exercise. There was no statistically significant difference between before experiment and after 6weeks' exercise. But, there was statistically significant difference between after 6weeks' exercise and 12weeks' exercise(F=9.38, P=0.0035). 4) Self-efficacy was decreased after 6weeks' exercise than that of before exercise. But, it was increased after 12weeks' exercise than that of be-fore exercise and after 6weeks' exercise. But there was no statistically significant difference (F=1.46, P=0.2706). 5) Quality of life was increased after 6weeks' exercise than that of before exercise, and after 6weeks' exercise than that of 12weeks' exercise. But there was no statistically significant differ once (F=1.06, P=0.3816). Thus, the significant of muscle strengthening exercise for the improvement of muscle strength, pain, depression, is verified. But, this study was a pre-experiment with small size subjects. So, con-trolled experimental study is necessary to determine the effect of this muscle strengthening exercise program on muscle strength, pain, depression, self-efficacy, and quality of life of patients with knee osteoarthritis.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.603-613
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• 2010

The Domi Basin in the South Sea of Korea is located between the Jeju Basin and Ulleung Basins, and is characterized by several sediment sags that are interested to have formed by crustal extension. This paper aims to derive an optimized seismic data processing procedure which helps stratigraphic interpretation of the Domi Basin. In particular, our data processing flow incorporated horizon velocity analysis (HVA) and surface-relative wave equation multiple rejection (SRWEMR) to improve the quality of stack section by enhancing the continuity of reflection events and suppressing peg-leg multiples respectively. As a result of processing procedures in this study, unconformities were recognized in the stack section that defines the early and middle Miocene, Eocene-Oligocene sequences. In addition, the overall quality of the stack section was increased as essential data to investigate the evolution of the basin. The suppression of multiple resulted in the identification of the Cretaceous basement. The data processing scheme evaluated through this study is expected to improve the standardization of processing sequences for seismic data from the Domi and adjacent Sora and north-Sora Basins.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.21-30
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• 2005

The purpose of this study is helps to make full use for perfect performance by grasping the defects of Tichonkich motion performed by athlete CSM For this, the study analyzed kinematical variables through Tichonkich motions performed at the first selection competition(1st trial) and final selection competition(2nd trial) for the dispatch to the 28th Athens Olympic Games using the three-dimensional cinematographical method with a high-speed video camera, and obtained the following results. 1. During Tichonkich motion, the execution time of up swing and the right hand moving to the left bar was shorter in the 2nd trial than the 1st one, while the execution time of down swing, the support of the left bar and the right hand moving to the right bar was longer in the 2nd trial than the 1st trial. 2. The horizontal position of COG in the 2nd trial was -35cm in the 1st stage, 42cm in the 3rd stage and 29cm in the 4th stage, that is, it showed a great swing focused on the circular movement compared to the 1st trial, while the vertical position of COG was -59cm in the 2nd stage, that is, it showed a small swing focused on a up and down movement. Also the 5th stage vertical position was 98cm, and the 6th stage vertical position was 95cm in the 2nd trial which were higher than those of the 1st trial, so it has provided magnificence required in the modern gymnastics. 3. And it was indicated that the horizontal velocity at the down swing phase proceeded forward more rapidly in the 2nd trial than that in the 1st trial, and the reverse ascent made a rapid vertical rise lessening left and right velocity change. And in the 5th stage, the 2nd trial was kept very slower in horizontal, vertical and left and right velocity that in the 1st trial, so it reached a handstand with leisurely movement. 4. In the 2nd trial, shoulder joint of the 1st, 2nd, 3rd stages kept a larger angle than that in the 1st trial, that is, it made a great swing while in the 1st trial, it showed a swing movement dependent on kick movement by the flexion and extension of hip joint. Also in the 2nd trial, the body formed a vertical posture with both hands supporting the left bar and hip joint was kept larger as $198^{\circ}$ and $190^{\circ}$ in the 5th and 6th stage than that in the 1st trial, so it made a handstand with the body uprightly stretched out, and magnificent and stable movement.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.33-42
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• 2008

The purpose of this study was to analyze kinematic variables during Side kick motion in Taekwon Aerobics. The subjects of this study were the 7 skilled and 7 unskilled female college students. A QTM and an Auto Track were used to acquire raw data. The sampling rates camera was 100 Hz. The parameters were calculated and analyzed with Visual3D and SPSS 12.0. The results were as following; 1. In the elapsed time, there was no significance difference statically between a skilled and unskilled group. 2. In the cases of knee angle, there was significant difference statically at Maximum Knee Flexion2(p=0.046, F=4.925). 3. In the cases of knee angular velocity, there was significant difference statically at Maximum Knee Flexion1(p=0.031, F=5.940). 4. In the flexion/extension of hip angle, there was significant difference statically at Maximum Knee Flexion2(p=0.012, F=8.668). 5. In the abduction/adduction of hip angular velocity, there was significant difference statically at Minimum Knee Flexion (p=0.019, F=7.324). 6. In the external rotation/internal rotation of hip angular velocity, there was significant difference statically Minimum Knee Flexion(p=0.005, F=11.87).

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.47-51
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• 2008

This study was carried out to get the basic data for safflower cultivation according to sowing date by growth analysis for 2 years form 2003 to 2004 at Institute of natural product in Uiseong, G.B.A.R.E.S.. Safflower(Cheongsoo cultivar) was seeded at March 1st, April 1st, May 1st, and July 1st in field. The necessary date for germination was 24 days, when safflower was seeded at March 1st, but it was 8 days which sowed at April 1st and when the seed was sowed at high temperature period, the necessary date for germination was getting short. The necessary date for flowering was the same trend as germination; it took 104 days at March 1st, 79 days at April 1st, 65 days at May 1st, and 58 days at July 1st sowing treatment. The safflower growth was the most vigor when it was sowed at March 1st. T/R(Top/Root) ratio was gently increased during growing season, but when the seed was sowed at July 1 st, it was low compare to sowing at March 1st and April 1st. RGR(Relative growth rate) was the highest during shoot growth stage, but it was rapidly decreased after flowering. CGR(Crop growth rate) was increased at branching stage, and the increasing velocity was slightly decreased just before flowering, and it was increased again at flowering and at this stage, CGR was the highest, and then it did not increased. NAR(Net assimilation rate) was the highest at shoot growth stage during growing season, and was the highest which was sowed at March 1st.