• Archives of Reconstructive Microsurgery
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• v.10 no.2
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• pp.111-117
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• 2001

Introduction : The Functional muscle transfer is used to reconstruct the injuried muscle and paralysis of the shoulder. Especially transfer of the trapezius has been the treatment of choice but it has disadvantages of inadequate function and deformed contour, and instability of humeral head in case of acromion resection. We report an operation for shoulder reconstruction after wide resection of malignant fibrous histiocytoma, using rotational latissimus dorsi flap and review the operation method and clinical outcome. Materials and Methods : A patient, 53 year old, with malignant fibrous histiocytoma in the acromioclavicular joint area had been underwent wide excision, including the deltoid, clavicular head of pectoralis major, part of trapezius, lateral 1/3 of clavicle and acromion including scapular spine. The rotational latissimus dorsi flap with its neurovascular pedicle was dissected and then placed over the resected area and transfer of muscle attached at coracoid process was done to achieve stability of the humeral head. The range of motion of the shoulder and test of muscle power were evaluated for functional outcome. Total follow-up period is 2 years 11 months. Results : At last follow-up, the range of motion of the shoulder is abduction $90^{\circ}$, flexion $90^{\circ}$, internal rotation $40^{\circ}$, external rotation $50^{\circ}$ and the muscle power is 4 grade in all direction and then we obtained good functional results. There are no complications such as instability or subluxation of the humeral head and deformed contour and he is a disease-free survival state. Conclusions : The transfered latissimus dorsi flap provides adequate lever arm and stabilization and covering of the humeral head by sufficient muscle volume and width. This procedure can be useful not only for the paralysed deltoid reconstruction but also for use in reconstructive surgery after wide resection of the shoulder for malignant tumor.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.285-293
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• 2012

The aim of this study is to identify the appropriate movement for maintaining postural balance during Front Kick and Turning Side Kick motions. To do so, ten Taekwondo athletes: five skilled players(S, body mass: $65.0{\pm}5.8kg$, height: $172.3{\pm}3.7cm$, age: $20.0{\pm}1.2yrs$, career: $9.0{\pm}1.9yrs$) and five less-skilled players(LS, body mass: $67.1{\pm}5.5kg$, height: $173.2{\pm}5.1cm$, age: $19.4{\pm}1.7yrs$, career: $9.6{\pm}1.7yrs$) participated in this study. A three-dimensional motion analysis was performed on the participants using eight infrared cameras and two force plate(sampling frequency of 200 Hz and 2000 Hz for S and LS players, respectively). The participants' motions were divided into: a front-kick phase(P1) and a turning-side-kick phase(P2). For P2(p<.05), the range and root mean square(RMS) of the ground reaction torque and the M-L mean velocity of COP were greater for LS than for S; similarly, for P2(p<.05), the M-L range, A-P range, and velocity of the COP were greater for LS than for S. Further, the M-L range and maximum velocity of the COP was greater for failure than for success(p<.05). The femoral biceps muscle for bending the knee joint was significantly stronger in S than in LS(p<.05). It is expected that these results will be useful in developing a training program for improving the balance and stability of Taekwondo poomsae athletes and improve their front-kick and turning-side-kick motions.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1139-1144
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• 2012

The ration of payload to weight of industrial robot amounts form 1:10 to 1:30. Compared with man who have a ration of 3:1, it is very low. One of the goals for the next generation of robots will be a ration. This might be possible only by developing lightweight robots. When two-link flexible arm is rotated about an joint axis, transverse vibration may occur. In this paper, vibration dynamics of flexible arm is modeled by using Bernoulli-Euler beam theory and Lagrange equation. Using the fact that matrix $\dot{D}-2C$ is skew symmetric, new controllers which have a simplified structure with less computational burden is proposed by using Lyapunov stability theory. We propose deterministic and adaptive control laws for two link flexible arm, and the validity of the proposed control scheme is shown in computer simulation for two-link flexible arm.

• Journal of Computing Science and Engineering
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• v.7 no.2
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• pp.99-111
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• 2013

Approximating a divergence between two probability distributions from their samples is a fundamental challenge in statistics, information theory, and machine learning. A divergence approximator can be used for various purposes, such as two-sample homogeneity testing, change-point detection, and class-balance estimation. Furthermore, an approximator of a divergence between the joint distribution and the product of marginals can be used for independence testing, which has a wide range of applications, including feature selection and extraction, clustering, object matching, independent component analysis, and causal direction estimation. In this paper, we review recent advances in divergence approximation. Our emphasis is that directly approximating the divergence without estimating probability distributions is more sensible than a naive two-step approach of first estimating probability distributions and then approximating the divergence. Furthermore, despite the overwhelming popularity of the Kullback-Leibler divergence as a divergence measure, we argue that alternatives such as the Pearson divergence, the relative Pearson divergence, and the $L^2$-distance are more useful in practice because of their computationally efficient approximability, high numerical stability, and superior robustness against outliers.

• Ocean and Polar Research
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• v.38 no.3
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• pp.247-257
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• 2016

The inter-comparison project for seawater salinity measurements, in which 25 laboratories from 16 countries took part, was conducted by JCOMM (Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology) for the first time in 2014. Two seawater samples of different salinity values ranging from 30-35 and 20-25 for Sample A and Sample B respectively and which had sufficient homogeneity and stability were distributed to all participants. Participants measured the salinity in their own laboratories at least 3 times and reported the results. Statistical treatments were applied to the results to assess discrepancies among laboratories. 20 out of the 25 laboratories used laboratory salinometers and statistics for this group were denoted as belonging to group ${\alpha}$; while 5 out of the 25 laboratories used hand-held measuring instruments and statistics for this group were denoted as belonging to group ${\beta}$. Bias described as discrepancy among laboratories in group ${\alpha}$ was within ${\pm}0.001$ and expanded uncertainty (k = 2) was in the vicinity of 0.002. The bias and the uncertainty of Korea Institute of Ocean Science and Technology (KIOST), in group ${\alpha}$, were 0.000 and 0.002, respectively. The biases of group ${\beta}$ were greater than group ${\alpha}$ because of constraints related to instrument accuracy. Biases from 3 laboratories in group ${\beta}$ exceed the accuracy specification of the corresponding instruments. Considering that the uncertainty of Standard Seawater (SSW) is of the order 0.001 to 0.002, the inter-comparison results show that 16 laboratories among the 25 laboratories made high quality measurements, largely indistinguishable from one another.

• Tunnel and Underground Space
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• v.13 no.4
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• pp.304-315
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• 2003

In this paper, the DDA method with a new hydro-mechanical algorithm is used to study the effect of rock discontinuities on uplift and seepage in concrete gravity dam foundations. This paper presents an alternative method of predicting uplift and seepage at the base of concrete gravity dams. A sensitivity analysis was carried out to study the importance of several parameters on dam stability such as the orientation, spacing, and location of discontinuities. The study shows that joint water flow and adverse geological conditions could result in unusual uplift at the base of concrete gravity dams, well in excess of what is predicted with the classical linear or hi-linear pressure assumption. It is shown that, in general, the DDA program with the hydro-mechanical algorithm can be used as a practical tool in the design of gravity dams built on fractured rock masses.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.778-791
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• 2005

A novel pneumatic artificial muscle actuator (PAM actuator), which has achieved increased popularity to provide the advantages such as high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks, has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. Then it is not easy to realize the performance of transient response of pneumatic artificial muscle manipulator (PAM manipulator) due to the changes in the external inertia load with high speed. In order to realize satisfactory control performance, a variable damper-Magneto­Rheological Brake (MRB), is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control method brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity, uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control method and without regard for the changes of external inertia loads.

• Journal of Conservation Science
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• v.19
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• pp.85-98
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• 2006

Rock property of the Seosan Maaesamjonbulsang is composed of biotite granite with medium grained texture. The triad Buddha is highly deteriorated by the joint, fracture, break-out, exfoliation, dew condensation of the surface and discoloration of the secondary pollutant. Host rock of the triad Buddha is divided dozens of rock blocks with various shape, and developed irregular discontinuity planes. Besides, the host rock is promoted biological pollution due to the surrounding crowded vegetation and high humidity environment. As the results of structural stability, it is confirmed that developed discontinuity system in the host rock is exposed instability sloping environment. Therefore, the host rock and surroundings are required maintenance, and required preservation by continuance monitoring for understand behavior of discontinuity system.

• Journal of Korean Neurosurgical Society
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• v.42 no.3
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• pp.179-183
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• 2007

Objective : Posterior arthrodesis in atlantoaxial instability has been performed using various posterior C1-2 wiring techniques. Recently, transarticular screw fixation (TASF) technique was introduced to achieve significant immediate stability of the C1-2 joint complex. The purpose of this study is to assess the clinical outcomes associated with posterior C1-2 TASF for the patient of atlantoaxial instability. Methods : We retrospectively reviewed data obtained from 17 patients who underwent C1-2 TASF and supplemented Posterior wiring technique (PWT) with graft between 1994 and 2005. There were 8 men and 9 women with a mean age of 43.5 years (range, 12-65 years). An average follow-up was 26 months (range, 15-108 months). Results : Successful fusions were achieved in 16 of 17 (94%). The pain was improved markedly (3 patients) or resolved completely (14 patients). There was no case of neurological deterioration, hypoglossal nerve injury, or vertebral artery injury. Progression of spinal deformity, screw pullout or breakage, and neurological or vascular complications did not occur. Conclusion : The C1-2 TASF with supplemental wiring provided a high fusion rate. Our result demonstrates that C1-2 TASF supplemented by PWT is a safe and effective procedure for atlantoaxial instability. Preoperative evaluation and planning is mandatory for optimal safety.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1983-1989
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• 2005

Industrial robots are powerful, extremely accurate multi-jointed systems, but they are heavy and highly rigid because of their mechanical structure and motorization. Therefore, sharing the robot working space with its environment is problematic. A novel pneumatic artificial muscle actuator (PAM actuator) has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. Its main advantages are high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks. The PAM is undoubtedly the most promising artificial muscle for the actuation of new types of industrial robots such as Rubber Actuator and PAM manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads in order to realize a human-friendly therapy robot To overcome these problems a novel controller, which harmonizes a phase plane switching control method with conventional PID controller and the adaptabilities of neural network, is newly proposed. In order to realize satisfactory control performance a variable damper - Magneto-Rheological Brake (MRB) is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control using neural network brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control using neural network and without regard for the changes of external inertia loads.