• Journal of KIISE:Computing Practices and Letters
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• v.8 no.6
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• pp.736-745
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• 2002

In network delivery of compressed video, packets may be lost if the channel is unreliable like Internet. Such losses tend to of cur in burst like continuous bit-stream error. In this paper, we propose an effective error-concealment approach to which an error resilient video encoding approach is applied against burst errors and which reduces a complexity of error concealment at the decoder using data hiding. To improve the performance of error concealment, a temporal and spatial error resilient video encoding approach at encoder is developed to be robust against burst errors. For spatial area of error concealment, block shuffling scheme is introduced to isolate erroneous blocks caused by packet losses. For temporal area of error concealment, we embed parity bits in content data for motion vectors between intra frames or continuous inter frames and recovery loss packet with it at decoder after transmission While error concealment is performed on error blocks of video data at decoder, it is computationally costly to interpolate error video block using neighboring information. So, in this paper, a set of feature are extracted at the encoder and embedded imperceptibly into the original media. If some part of the media data is damaged during transmission, the embedded features can be extracted and used for recovery of lost data with bi-direction interpolation. The use of data hiding leads to reduced complexity at the decoder. Experimental results suggest that our approach can achieve a reasonable quality for packet loss up to 30% over a wide range of video materials.

• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.157-169
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• 1999

Eighty-nine shoulders in eighty-eight patients with traumatic unilateral anterior shoulder instability were evaluated for Rowe and UCLA scores, recurrence, return to activity, and range of motion by an independent examiner at an average of 39 months after either arthroscopic or open Bankart repair using suture anchors. The arthroscopic technique included a minimum of 3 anchors, and a routine incorporation of capsular plication and proximal shift. Twenty­six shoulders(86.6%) out of thirty in the open Bankart repair group had excellent or good results while fifty­four(91.5%) of the fifty-nine shoulders with arthroscopic Bankart repair had excellent or good results. The arthroscopic group revealed significantly better results in the Rowe(p=.041) and UCLA scores(p=.026). Two shoulders in each group developed redislocation. There were no significant differences in the loss of external rotation and return to prior activity between the two groups(p>.05). The residual instability occurred more frequently in the group of patients with lesser anchors. Arthroscopic suture anchor capsulorraphy has results equal to or better than the open Bankart procedure.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.1
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• pp.77-86
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• 2013

This study was introduced the short-term effectiveness of Oriental medicine treatment for lumbar disc herniation inpatients. We selected 208 inpatients with a magnetic resonance imaging(MRI)-confirmed lumbar disc herniation since June 2012 until August 2012. Their demographics characterisitics, numeric rating scale(NRS) and Oswestry back-related disability index(ODI) for low or leg pain, lumbar flexion and extension angle were assessed at baseline and when discharged from the hospital. When it measured the straight leg raisingscale(SLR), the low side of the angle was examined. Treatment every patient has received as follow; herbal medicine, bee venom, acupuncture and physical examination, spinal manipulation. NRS of low back pain and leg pain and ODI is $5.6{\pm}2.3$, $4.9{\pm}2.8$ and $45.5{\pm}20.0$, respectively at baseline and $2.8{\pm}1.8$, $2.7{\pm}1.9$ and $27.2{\pm}14.1$, respectively when discharged from the hospital. range of motion(ROM) of lumbar flexion and extension angle and SLR is $70.0{\pm}27.1$, $15.4{\pm}7.2$ and $61.3{\pm}23.0$ respectively at baseline and $80.5{\pm}16.9$, $18.25{\pm}4.1$ and $73.2{\pm}14.0$, respectively when discharged from the hospital. It shows that statistically significant improved(P<0.001). Furthermore, regarding patient satisfaction with the treatment, excellent(33.7%), good(55.4%), normal(10.4%), poor(0.5%), it suggests that most patients(89%) satisfied with the treatment.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.137-143
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• 2009

This study was conducted to evaluate the accuracy of CyberKnife $Synchrony^{TM}$ respiratory tracking system which was applied to Stereotactic Radiosurgery (SRS) for moving tumors in chest and abdomen with breathing motion. For accurate evaluation, gold fiducial marks were implanted into a moving phantom. The moving phantom was a cube imbedding an acryl ball as a target. The acryl ball was prescribed to 20 Gy at 70% of isodose curve in a virtual treatment and radiochromic films were inserted into the acryl ball for dose verification and tracking accuracy evaluation. The evaluation of position tracking consists of two parts: fiducial mark tracking in a stationary phantom and $Synchrony^{TM}$ respiratory tracking in a moving phantom. Each measurement was done in three directions and was repeated to 5 times. Range of position error was 0.1957 mm to 0.6520 mm in the stationary phantom and 0.4405 mm to 0.7665 mm in the moving phantom. Average position error was 0.3926 mm and 0.5673 mm in the stationary phantom and the moving phantom respectively. This study evaluates the accuracy of CyberKnife $Synchrony^{TM}$ Respiratory tracking system, and confirms the usefulness when it's used for Stereotactic Radiosurgery of body organs.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.3
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• pp.83-89
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• 2002

Purpose: To analyze the postoperative functional and radiographic follow-up results in patients who underwent percutaneous radiofrequency ablation therapy after the diagnosis of osteoid osteoma. Materials and Methods: Seven patients, who were clinically and radiographically diagnosed with osteoid osteoma from July 1999 to January 2001, and received percutaneous radiofrequency ablation therapy. The average follow-up period was 15.5 months(range, 8~25 months). For the diagnosis and accurate localization of the lesion, simple radiography, computed tomography and magnetic resonance imaging(MRI) were performed preoperatively. Simple radiographs and MRI were taken periodically for the follow-up studies. Results: In all 7 patients, symptoms completely disappeared within 3 days after the operation. The average period of hospitalization was 2.4 days, excluding 1 patient who needed an additional burn treatment. The average postoperative night and day pain scores were 1.8 and 1.3, respectively. The average vocational and recreational activity scores were 1 and 0.6, respectively. Conclusions: Satisfactory functional results were obtained with percutaneous radiofrequency ablation therapy for the elimination of osteoid osteoma. Compared to conventional treatment, the advantages of this therapy were short hospitalization period, no internal fixation and bone graft for preventing fracture, and no limitation of joint motion by long fixation period.

• PNF and Movement
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• v.16 no.1
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• pp.43-50
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• 2018

Purpose: This study examined the effects of a shoulder-strengthening exercise on muscle strength of shoulder flexors and extensors of caregivers. Methods: The study consisted of 19 caregivers (2 males and 17 females) employed by Medical Center B. All the participants took part in an 8-week shoulder muscle strengthening exercise, based on previous studies. In the first week, the subjects took part in a stretching exercise enhance the range of motion. In the second week, they participated in an exercise aimed at improving shoulder blade stability. From the third to seventh weeks, a resistance exercise of different intensities was applied in a phased manner. Finally, in the eight week, the subjects took part in plyometric exercise. Peak torque, average power, and total work of shoulder flexors and extensors in both sides were measured before and after the exercise at an angular speed of 120deg/sec using an isokinetic device. Wilcoxon's singed-ranks test was conducted to analyze differences in muscle strength before and after the intervention. Results: After the exercise, there was a significant improvement in peak torque and average power of flexors of the right arm. After the exercise, peak torque, total work, and average power showed a significant improvement in the flexors of the left arm (p<0.05). However, there was no statistically significant difference in extensor muscle strength in either arm after the exercise. Conclusion: Shoulder flexors of caregivers are utilized frequently in the workplace. Implementation of extensor-strengthening exercises, in addition to flexor-strengthening exercises, can contribute to reducing the incidence rate of shoulder injuries among caregivers.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.89-99
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• 2006

The study were to assess technical factors between the high score group and the low score group, from the subjects of 16 male national gymnasts, and to analyze the kinematical characteristic and main technical cause on technique of Akopian's 3D motion analysis of the male vaulting game in 2001 classification championship. The result of this study is this. There were not so much difference between the two groups in term; of the time of board contact, pre-flight, and total performance, but it takes shorter time when the players who are in the high point group take down the board, and they take long time for post-flight(p<.01). The high point group has a longer perpendicular distance in the moment of horse taking off, 0.05m on the average, than the low point group. The high point group shows 0.16m higher on the average than the other group in term; of the height of post-flight(p<.01). In the phase of board contact, the range of horizontal velocity at board take on were $7.66m/s{\sim}7.33m/s$, but there weren't significantly statistic differences between two groups. The hight score group were 0.68m/s faster than the low point group at the horizontal velocity at board take off event(<.05). About the average horizontal velocity of deceleration, AG1(-1.95m/s) reduces the speed more than AG2(-1.57m/s)(p<.05). And the hight score group were 0.37m/s faster than the low point group at the vertical velocity at horse take off event(<.05). When board taking off, the projectile angle of com were $38.7{\sim}37.8degree$ on the average. the comparative groups show almost same results. When horse taking off, the HPVy of the high point group were 37.6 degree which were a little higher than the low point group. The angular velocities of the players who takes on the horse with a right hand and then takes off with a left hand in the high point group were 14.97rad/sec, 10.82rad/sec in the low point group. However, the angular velocity of the players who takes on the horse with a left hand and then takes off on a right hand with the high point group were 14.97rad/sec, 15.56rad/sec in the low point group.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.399-406
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• 2009

The purpose of this study was to compare the effect of wearing roller shoes and jogging shoes on kinematic characteristics in lower extremity during walking. Eight male middle school students(age: $15.0{\pm}0.0^{\circ}$ yrs, height $175.9{\pm}6.6cm$, weight: $616.3{\pm}84.9$ N) who have no musculoskeletal disorder were recruited as the subjects. Temporal parameters, step length, stride length, center of mass, velocity of CM, angle of segment, angular velocity and range of motion were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions(p < .05). The results showed that stride length and velocity of CM in wearing roller shoes were significantly less than those found in wearing jogging shoes. These indicated that walking patterns may be changed by different shoe conditions and unstable braking condition because of wheel. Angle of ankle joint at LHC1 and LHC2 in wearing roller shoes was greater than the corresponding value for wearing jogging shoes. It seems that the ankle joints are locked in an awkward fashion at the heel contact to compensate for imbalance. Otherwise, dorsi flexion was not produced at the heel contact point in wearing roller shoes.

• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.530-542
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• 2005

In this study, GIS method has been used to get fractal characteristics. Using the projected area and surface area, 2 dimensional fractal characteristic of terrain was found out. Correlation of fractal dimension and mean slope were also checked over. Results are as below. 1) To get a fractal dimension, the method which is using the surface area is also directly proportional to complexity of the terrain as other fractal dimension. 2) Fractal dimensions using the surface area, that is proposed in this thesis are carried out as below : Uiseong : $2.02{\sim}2.15$ Yeongcheon : $2.10{\sim}2.24$. These values are in a range of fractal $2.10{\sim}2.20$ dimensions which has known. 3) Correlation of mean slope and fractal dimension is diminished about 30% in a region which is more than $25^{\circ}$ of mean slope. So, in this region using the fractal dimension method is better than using the mean slope. From this study, on formula using the projected area and surface area is still good to get a fractal dimension that has been found. But to confirm this method the region of research should be wider and be set up the correlation of mean slope, surface area and fractal dimension. It can be applicable to restoration of terrain and traffic flow analysis in the future research.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.276-282
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• 2015

Recently, during the multi-level fusion with pedicle screws, interspinous spacer are sometimes substituted for the most superior level of the fusion in an attempt to reduce the number of fusion level and likelihood of degeneration process at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the interspinous spacer combined with posterior lumbar fusion with a previously-validated 3-dimensional FE model of the intact lumbar spine (L1-S1). The post-operative models were made by modifying the intact model to simulate the implantation of interspinous spacer and pedicle screws at the L3-4 and L4-5. Four different configurations of the post-op model were considered: (1) a normal spinal model; (2) Type 1, one-level fusion using posterior pedicle screws at the L4-5; (3) Type 2, two-level (L3-5) fusion; (4) Type 3, Type 1 plus Coflex$^{TM}$ at the L3-4. hybrid protocol (intact: 10 Nm) with a compressive follower load of 400N were used to flex, extend, axially rotate and laterally bend the FE model. As compared to the intact model, Type 2 showed the greatest increase in Range of motion (ROM) at the adjacent level (L2-3), followed Type 3, and Type 1 depending on the loading type. At L3-4, ROM of Type 2 was reduced by 34~56% regardless of loading mode, as compared to decrease of 55% in Type 3 only in extension. In case of normal bone strength model (Type 3_Normal), PVMS at the process and the pedicle remained less than 20% of their yield strengths regardless of loading, except in extension (about 35%). However, for the osteoporotic model (Type 3_Osteoporotic), it reached up to 56% in extension indicating increased susceptibility to fracture. This study suggested that substitution of the superior level fusion with the interspinous spacer in multi-level fusion may be able to offer similar biomechanical outcome and stability while reducing likelihood of adjacent level degeneration.