• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.41-49
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• 2014

Detection and processing techniques for small objects on seabed by the active synthetic aperture sonar can be increased the detection performance because it can be used by short sensor array in small unmanned underwater systems that are spatially constrained. But the limited conditions on constant speed and straight movement of the platform cause a large error in the number of external environmental factors and exact phase synthesis process. In this study, analyzed the applicability of active synthetic aperture processing that is mounted on such a system, and compared detection resolution change in accordance with the phase difference mismatch caused by the along track disturbance. Various simulations were performed as a coherently focus processing model by adding along track disturbance mismatched parameter on the configuring simulator. As the result, detection performance of active synthetic processing for small objects on seabed was found a number of changes by the phase difference mismatch errors according to track disturbances and S/N ratio variations.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.441-447
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• 2007

Internal derangement of the temporomandibular joint(TMJ) is defined as an abnormal relationship of the articular disc to the condyle. Mandibular manipulation is one of the conservative treatments to be considered first to manage the patients with anterior disc displacement without reduction. Mandibular manipulation is used to increase articular mobility and to restore the displaced disc into an anatomically normal position. While Farrar's technique has been popularly used, Minagi et al., Mongini and Suarez introduced the manipulation technique conducted by the patients themselves. But there is no study on the efficacy of self-manipulation technique, comparing with conventional one. The aim of this study was to investigate the efficacy of the conventional and self-manipulation technique, which was modified to complement the previously described technique by Minagi et al., in the treatment of patients with anterior disc displacement without reduction. TMD patients, who visited Department of Oral Medicine of Seoul National University Dental Hospital from December, 2002 to November, 2004 and were diagnosed as anterior disc displacement without reduction by TMJ magnetic resonance imaging (MRI) were enrolled. Conservative treatments including physical therapy, exercise, behavioral therapy, stabilization splint therapy, and manipulation therapy were done to every single patient until the symptomsimproved enough to discharge the patient. The charts were reviewed retrospectively according to the type of manipulation. In the results, patients whose maximum mouth opening was more than 40 mm was higher in the self-manipulation group(69.9%) than in the conventional manipulation group(42.9%). But difference between two groups was not significant. According to the fact that we decided to discharge the patients whentheir mouth opening increased to more than 40 mm and subjective symptoms such as pain and discomfort were improved as well, treatment period of discharged patients was significantly shorter in the self-manipulation group($29.2{\pm}12.3$ weeks) than in the conventional manipulation group ($61.0{\pm}38.0$ weeks) (p<0.01). In conclusion, in the treatment of TMD patients with anterior disc displacement without reduction, the self-manipulation technique which is performed by patients themselves is an effective treatment modality for increasing the range of mouth opening and shortening the total treatment period.

• Journal of Oral Medicine and Pain
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• v.35 no.2
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• pp.149-154
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• 2010

In benign exophytic lesion in TMJ such as osteoma, chondroma, osteochondroma, synovial chondromatosis etc, symptom such as pain, mouth opening limitation, Most case of condylar exophytic lesion manifest with facial asymmetry, malocclusion, mandibular midline deviation. An osteochondroma and synovial chondromatosis are most commom benign condylar tumor. However this tumor is most frequently found on long bone and flat bone and is unusual on the skull. We report cases of osteochondroma, synovial chondromatosis of TMJ and review literatures.

• Journal of Oral Medicine and Pain
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• v.38 no.4
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• pp.357-366
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• 2013

This study is designed to evaluate the treatment outcome of occlusal stabilizing splint and to assess follow-up study of condylar bony changes using cone beam computed tomography(CBCT) in adolescents patients (12-19 years) with TMJ osteoarthritis(OA). 167 eroded condyles in 149 subjects were chosen among the patients who presented to the Department of Oral Medicine of Pasan National University Hospital, diagnosed as TMJ osteoarthritis by clinical exam, x-ray and CBCT from 2009 to 2012. They were treated conservatively with physical therapy, medication, behavioral therapy and occlusal stabilizing splint therapy. After average 9 months, CBCT was retaken and subjective symptoms and clinical findings were investigated. Condyle bony changes were classified by unchanged, less severe and more severe. The obtained results were as follow: 1. Pain, Noise, LOM(Limitation of motion) and MCO(Maximum comfortable opening) measurement of TMJ OA patients were markedly improved after conservative treatment. 2. In the occlusal stabilizing splint therapy group, Pain and LOM were statistically significant improved than non-occlusal stabilizing splint therapy group. 3. In the acute occlusal stabilizing splint therapy group, Pain and LOM were remarkably improved. 4. In comparison of CBCT1 and CBCT2 images, the transition of bone changes to lesser severe was most commonly in joint with erosive change. 5. In the non-occlusal stabilizing splint therapy group, the transition of condylar bone changes from erosion to more severe was many than occlusal stabilizing splint therapy group.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.636-644
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• 1999

Experimental and simulation results are presented on the Aperture-Coupled microstrip patch antennal with U-shaped slot. Experiment and simulation results include impedance bandwidth, copolar and crosspolar-pattern characteristics and gain measurements. Simulation results show the advantages of U-slotted patch antenna comparing with the normal patch antenna. More than 35% impedance bandwidth is obtained with reasonably restricted cross-polar radiation pattern. The U-slotted radiation element fed by aperture-coupling method can be more easily extended to array structure, compared with that fed by coaxial cable.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.198-205
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• 2005

In this paper, the miniaturization of aperture-coupled RHCP patch antenna for the GPS system is treated. Circularly polarization characteristics is implemented by truncating diagonal corners of the square patch. Antenna size is reduced by inserting four uniform slits at the patch edges, which was equivalently lengthened the surface current by meandering it, This antenna uses aperture-coupled feeding structure with crossed-slot shape in order to give easy miniaturization of RHCP patch antenna. Simulated and measured results show that $42.7\%$ lower antenna size is obtained, and also $56\%$ lower -10dB bandwidth and $38.5\%$ lower 3dB AR bandwidth are obtained. when the proposed design scheme is applied to a commercial GPS antenna structure, $42.9\%$ lower patch size and $56\%$ lower 3dB AR bandwidth compared to commercial antenna at the same frequency are obtained.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.167-180
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• 1997

79 surgically managed mandibular condylar fracture patients included the 25 patients treated with Dr, Nam's method were analysed the postoperative resluts in Oral and Maxillofcial Surgery, School of Dentistry, Wonkwang University since 1993 to 1995. Mean patient's age is 32.5 years (range, 8 to 65 years), and follow-up periods were a minimum of 3 months to 28 months. 19% condylar fractures were associated with mostly symphysis portion. According to the patient's age, severity of condylar fractures, clinical signs and symptoms, radiographic findings, treatmenet plans had been performed. Rigid fixation have performed greatly, and then fragment removal of fractured mesial pole of proximal segment of the condylar and little cases of reshaping and eminoplasty and lag screw have been applied. Two cases of the both condylar resorption and deviated condyle posteriorly in Dr. Nam's method. None of infection or necrosis signs of treated condyle surgically. In my opinion, whenever possible, displaced condylar fracture can be managed surgically with rigid fixation, but not Dr. Nam's method. Usually if perform the surgical management of condylar fractures you should maintain maxillomandibular fixation for 2 weeks, or more and has to follow-up functional mandibular exercise should be kept continuously.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.260-261
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• 2003

최근들어 플라스틱 렌즈는 여러 분야에 응용되고 있으며 광학적 시스템에도 널리 사용되고 있다. 광학적 플라스틱은 제작이 용이하고 크기에 제한을 받지 않아 그 수요가 크게 확대되고 있다. 그러나, 광학적인 시스템에 사용되기 위해서는 높은 순도가 요구되면서 또한 재질의 균일성이 확보되어야 하고 개구율이 점차 높아 가는 현실에서는 그 특성의 연구가 또한 중요하다. 본 연구에서는 간섭계를 구성하여 광학 디스크 경사에 따른 파면을 측정하고 광학수차 평가를 통하여 광학적인 시스템에 미치는 영향을 분석하였다. (중략)

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.545-550
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• 2010

Freeman-Sheldon Syndrome (FSS, also known as "Whistling Face Syndrome") is a rare genetic condition which characteristically includes a small "whistling" mouth, a flat mask-like face, club feet, joint contractures usually involving the fingers and hands, and under-development of the cartilage of the nose. Intelligence is usually normal. Most of the features of this syndrome are due to muscle weakness. The patient, 11 years old boy was consulted from pediatrics to pediatric dentistry due to dental management. After clinical & radiographic examinations, severe multiple problems were found. Dental problems were microsomia(whistling mouth) & micrognathia, perioral muscle contracture, restricted mouth opening, poor oral hygiene & care, generalized dental caries, high palatal vault, severe malocclusion & crowding. And Orthopedic problems, ophthalmic & respiratory, anesthetic problems were found. Then He also had psychiatric problem, hospital(dental) phobia due to previous medical history(frequent hospitalization). And he had genital problem, cryptochidism, too. Due to these intricate problems, he suffered with feeding, swallowing difficulties and showed growth retardation. For enhancing patient's oral health, pediatric dentist, orthodontist, oral surgeon, pediatrician, psychiatrist, orthopedist, they all agree with early, cautious intervention and treatment. So, he has been treated by multidisciplinary care, now he is recovering general health maintenance.

• Journal of Oral Medicine and Pain
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• v.33 no.4
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• pp.395-399
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• 2008

Orofacial pain and limited range of mouth opening as symptoms of temporomandibular disorder are mainly triggered by the structural and/or functional changes of temporomandibular joint and related structure itself. But careful diagnostic evaluation should be needed because they may be occurred by another pathologic conditions such as neoplasm in head and neck region. If there would be atypical pain characteristics or clinical features, systemic comorbid symptoms, or poor response to treatment, advanced imaging modalities such as CT or MRI will be mandatory for differential diagnosis. We experienced the case which was diagnosed as nasopharyngeal cancer mimicking temporomandibular disorder, and reviewed clinical considerations for proper differential diagnosis.