• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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• pp.589-597
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• 2011

In this paper, optimal tuning of a cross-coupled controller linked with the feedforward controller and the disturbance observer is studied to improve contouring and tracking accuracy as well as robustness against disturbance. Previously developed integrated design and optimal tuning methods are applied for developing the robust tuning method. Strict mathematical modeling of the multivariable system is formulated as a state-space equation. Identification processes of the servomechanism are conducted for mechanical servo models. An optimal tuning problem to minimize both the contour error and settling time is formulated as a nonlinear constrained optimization problem including the relevant controller parameters of the servo control system. Constraints such as relative stability, robust stability and overshoot, etc. are considered for the optimization. To verify the effectiveness of the proposed optimal tuning procedure, linear and circular motion experiments are performed on the xy-table. Experimental results confirm the control performance and robustness despite the variation of parameters of the mechanical subsystems.

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.259-262
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• 2006

Fibrous dysplasia(FD) of the bone is a slowly progressive, benign disease of unknown cause where normal architectures are replaced with fibrous and osteoid tissue. FD of the maxilla usually manifests as a bony enlargement with painless swelling and bone deformity, contouring to facial asymmetry. The lesion may involve the nasal fossae, orbits, or alveolus bone, causing diverse functional disturbance. Treatment options range from shaving to total maxillectomy and reconstruction depending on the presenting symptoms. Shaving, partial maxillectomy and maxillary sinus formation was performed in 5 patients with fibrous dysplasia in the past 2 years. Follow up period ranged from 1 month to 11 months. Aesthetic appearance, CT findings, and relief from symptoms were compared. In all patients, facial asymmetry was restored to symmetry and nasal obstructive symptoms were improved. With this procedure, expansion of the lesion will be controlled until puberty, preventing the development of new functional disturbances. After puberty, no further treatment can be anticipated due to the growth arrest inherent to the disease.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.389-397
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• 1997

In this paper, we propose a new method of contour error modeling for cross-coupled control of CNC machines. This modeling method is based on the information that the interpolator of a CNC machine generates knot points per each sampling time in order to approximate a given curved path as a series of small straight-line segments. The merits of the proposed method are : (1) its applicability for arbitrary curved contours and (2) its ability to calculate contour errors more accurately than the other conventional methods. The proposed method is evaluated and compared with the conventional methods using the three typical curved trajectories by computer simulations. Furthermore, it is shown that the cross-coupled controller based on this proposed error model improves contouring accuracy more effectively than the other methods.

• Archives of Plastic Surgery
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• v.43 no.4
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• pp.321-327
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• 2016

There are many women who want larger and brighter eyes that will give a favorable impression. Surgical methods that make the eye larger and brighter include double eyelidplasty, epicanthoplasty, as well as lateral canthoplasty. Double eyelidplasty produces changes in the vertical dimension of the eyes, whereas epicanthoplasty and lateral canthoplasty create changes in the horizontal dimension of the eyes. Epicanthoplasty, a surgical procedure which enlarges the eye horizontally, is performed at the inner corner of the eye, whereas lateral canthoplasty enlarges the outer edge of the eye. In particular, if the slant of the palpebral fissure is raised and the horizontal dimension of the palpebral fissure is short, adjusting the slant of the palpebral fissure through lateral canthoplasty can achieve an enlargement of eye width and smoother features. Depending on the patient's condition, even better results can be achieved if this procedure is performed in conjunction with other procedures, such as double eyelid-plasty, epicanthoplasty, eye roll formation surgery, fat graft, and facial bone contouring surgery. In this paper, the authors will introduce in detail their surgical method for a cosmetic lateral canthoplasty that lengthens the lateral canthal angle and corrects the outer tail of the eyes, in order to ease the unfavorable impression.

• Archives of Plastic Surgery
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• v.42 no.1
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• pp.68-72
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• 2015

For recent years, use of autologous fat injection has increased significantly in facial contouring surgery. Along with such increase in use, complications like atypical mycoplasma infection have been also on the increasing trend. The authors report two cases of Mycobacterium chelonae infection that occurred after autologous fat injection. Patients were treated as infection that resistant to common antibiotics and results were negative to routine culture and Gram staining. Acid-fast bacillus stain, polymerase chain reaction (PCR) test and mycobacterial cultures were conducted for diagnosis under suspicion of atypical mycoplasma infection. Then, combination antibiotics therapy, surgical treatment, and steroid injection were performed for treatment. Both patients were diagnosed with Mycobacterium chelonae in PCR test. They were positive to mycobacterial cultures. Combination antibiotics therapy was repeated to improvement of symptom. However, they could not be free from side effects such as deformation in facial contour, scar and pigmentation even after full recovery. When chronic wound infections after autologous fat injection, we must suspect atypical or mycobacterial infection and conduct examinations for a early diagnosis and proper antibiotic therapy that is effective to the nontuberculous mycobacteria.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.124-134
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• 1992

Fibrous dysplasia is a benign pathologic condition of bone in which fibrous tissue gradually expands and replaces normal bone into fibro-osseous lesion. It is a primary developmental abnormality of bone-forming mesenchyme in origin. This study shows clinical history, radiological and histopathological feature of fibrous dysplasia with the intention of establishing correct diagnosis, treatment plan and evaluation of prognosis. This paper reviews and summarizes the materials from 57 fibrous dysplasias submitted to the Department of Oral and Maxillofacial Surgery in College of Dentistry, Seoul National University. Conclusions obtained were as following : 1. Fibrous dysplasia developed mainly in teenagers and shows female predeliction. 2. Fibrous dysplasia developed much on the maxilla 3. Monostotic fibrous dysplasia was most popular form. 4. Main symptom of fibrous dysplasia was painless swelling. 5. Radiological feature of fibrous dysplasia was ground-glass appearance, 6. Histopathological feature of fibrous dysplasia was irregular immature bony trabeculae(woven bone). 7. Treatment of fibrous dysplasia was mainly conservative contouring surgery.

• Journal of Technologic Dentistry
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• v.11 no.1
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• pp.47-63
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• 1989

The study was made to clarify the degree of fatigue of dental technicians in service at the general &local hospital or the dental laboratories in the large cith of korea. The objectives of this study were 235 dental technicians who replied the questionaire which was sent by postal service out of 600 dental technicians selected by random sampling among the workers of the each dental laboratory. The instruments used in this study was the same one as developed by Industry Fatigue committee of Japan Industry Hygiene Association. This instrument was included total 30 items which is consisted of 10 perceived symptoms of fatigue in physical, mental and neuro-sensory dimension respectably. Reliability was tasted with the data of objectives, in which value of Cronbach's $\alpha$ was 9457. The following results were obtained. 1. It was revealed that the influencing demographic variables on the perceived symptoms of fatigue of dental technicians were sex, age, marital status, educational background, job carrier, working part, working hour and commuting hour. The shorted the age or job carrier, thge higher dearee of the perceived symptoms of fatigue. The longer working hours of commuting hours, the higher degree of the perceived symptoms of fatigue. The degree of the perceived symptoms of fatigue in females, unmarried person, the one with higher educational background, workers except orthodontic appliances and poorcelain contouring were higher than the other group. 2. The higher degree of the rest & leisure condition, the lower degree of the physical, mental and neuro-sensory perceived symptoms. 3. The higher degree of environmental condition of the working, the lower degree of the physical, mental and neurosensory perceived symptoms.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.100-107
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• 2001

On the planning for the systematic management and control of the air pollution display methods were used to evaluate the spatial pollutant concentration status. This study were conducted to investigate the practical using of Geographic Information System(GIS) technology on the air pollution control and management which were computer-based systems that were used to store and manipulate geographic information in the macro city. In this study 137 samples were corrected by passive samplers and analysed by GC/MSD for 16 VOCs in Seoul (25 distincts) distributed by TM-coordinate(2 km$\times$2km), and finally displayed by Arciew program(version 3.2, ESRI Inc, USA) for windows. The concentration of benzene and toluene showed high level in whole area of seoul area of Seoul and distribution of butylbenzen, trothroloetylene, stylen showed high level in whole area of Seoul except a few distincts and the distribution of isopropylbenzene, 1,2-dichroloethane showed higher level in core area than that of Kangnam and Kangbuk area. In conclusion, products of this study of using GIS technology apply on the spatial distribution of VOCs concentration was very effective than that of other methods(e.g., contouring concentration method, pie or column chart, graduated symbols), especially in mapping and symbolization of pollution status evaluation.

• Journal of the Korean Society of Safety
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• v.11 no.1
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• pp.133-141
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• 1996

In spite of a tendency automatizing manaufacturing processes, since power presses are highly repetitive at high speeds, they have still been using to a large extent in many industries. More often than not, press workers have to make decisions whether work materials are located well or not, they should rearrange them or not, and their bodies would be safe or not. If the decision would be wrong, of course, they cause severe damages to human workers so that many workers haven't been willing to work with them. However, with the help of computer technologies, it would be possible to aid the press workers' decisions, and to allow or prohibit them from inserting their hands between slide rams and dies. Thus, this research was aimed to evaluate and analyze possibilities of applying Image Processing Techniques for prevention of press accidents. Through a series of procedures including Capturing work sites and material, Image Enhancement, Contouring, and Edge Finding, work characteristics were obtained and analyzed. The results showed that there were somewhat differences in image characteristics between accident-induced work scenes and accident-free ones. Consequently, if the image analyses are well carried out in real time, they would give a successful help to human press workers.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.409-414
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• 2010

Purpose: Poland's syndrome encompasses a constellation of congenital chest wall, breast, and upper extremity deformities. We would like to present several techniques, which may be combined if necessary, used to treat the forms involving both the breast and chest wall according to the degree of deformity. Methods: In a retrospective series of 9 patients (3 men and 6 women), we report our experience with reconstructing breast and chest contour deformities associated with Poland syndrome. We recorded their age, gender, the surgical techniques, and the grade in Poland's syndrome according to the classification of Foucras. Results: The breast and chest wall deformities associated with Poland syndrome can be treated in individualized fashion according to the classification of Foucras. In case of 3 male patients with gradeI, II, the latissimus dorsi muscle pedicled flap improved the chest contour deformity. 3 female patients with grade II underwent the latissimus dorsi muscle pedicled flap with breast implant. 2 female patients with gradeIunderwent breast reconstruction with breast implant and fat injection each other. One female patient with severe chest wall deformity (grade III) underwent breast reconstruction using the free TRAM flap. All patients were satisfied with the results without specific complications. Conclusion: The Individualized correction for this syndrome according to the degree of patient's deformity and preference made the overall satisfaction of the patients high.