• Journal of Ocean Engineering and Technology
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• v.21 no.3 s.76
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• pp.71-76
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• 2007

Recently, many industries have been employing the application of laser beam welding, due to the resulting high welding quality, such as smaller width of melting and heat affective zone, smaller welding deformation, and fine grains of weldment, compared to arc welding. However, in order to appropriately utilize this welding process with steel structure, the characteristics of welding residual stresses and fracture toughness in welded joints are to be investigated for reliability. Therefore, in this study, the mechanical properties of weldments by arc and laser welding are investigated using FEM to confirm the weldability of laser welding to the general structural steel (HT50). The Charpy impact test and 3-points bending CTOD test are carried out in the range of temperatures between $-60^{\circ}C\;and\;20^{\circ}C$, in order to understand the effect on the fracture toughness of weldments. From the research results, it has been found that the maximum residual stress appears at the center of plate thickness, and that the fracture toughness is influenced by strength mis-match.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.101-104
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• 1998

Backgrouds: Twent five years have passed since the opening of the first pain clinic in korea, in 1973 at Yonsei University Hospital. The number of pain clinics are gradually increasing in recent times. It is important to plan for future pain clinics with emphasis on improving the quality of pain management. Therefore we reviewed the patients in our hospital to help us in planning for the future of our pain clinic. Methods: We analyzed 2656 patients who had visited our Kim Chan Pain Clinic, accordance to age, sex, disease, and type of treatment block, from July 1996 to August 1997. Results: The prevalent age group was in the fifties, 27.3%, seventy years and older compromised 9.2%. The most common disease were as follows: lower back pain(46.2%); cervical and upper extremities pain(23.1%); trigeminal neuralgia(7.2%); and hyperhydrosis(5.8%) Both nerve blocks and medication were prescribed as treatment. Lumbar epidural block(16.3%) and stellate ganglion block(15.6%) were the most frequent blocks performed among various nerve blocks. Among nerve block under C-arm guidance, lumbar facet joint block(24.4%) and lumbar root block(22.5%) were performed most frequently. Trigeminal nerve block(18.4%), thoracic(17.0%) and lumbar sympathetic ganglion block(11.4%) were next most prevalent blocks performed frequent block. Conclusions: Treatments at our hospital were focused on nerve blocks and medications prescriptions. Nerve blocks are of particular importance in the diagnosis and treatment of chronic pain. However in future, to raise the quality of pain management, we need to fucus on a multidisciplinary/interdisciplinary team approach.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.95-102
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• 2001

Temporomandibular ankylosis is defined as a situation in which the condyle is fused to the fossa by bone or fibrous tissue. Conditons such as trauma, infection, or systemic disease may predispose to various types of ankylosis, bringing about different levels of limitation in mandibular movement. Most patients with temporomandibular ankylosis are associated with limitation of maximal mouth opening, deviation of the chin toward the affected side, impaired occlusion, chronic pain, compromised oral hygiene, severe facial asymmetry & impeded mandibular molar eruption occurring in childhood. Several techniques to release ankylosis have been described in the literature, showing variable and often unsatisfactory results. The most frequently used operations are gap arthroplasty, interpositional arthroplasty, and exicision and joint reconstruction with autogenous or alloplastic materials. We have managed the two patients of TMJ ankylosis. They had previously TMJ surgery and we treated with gap arthroplasty & active physial therapy. We have obtained favorable results and report these cases with literatures review.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.53-76
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• 1991

The study was designed to analyse the reorganization of the rabbit TMJ meniscus which was anteriorly displaced by surgery. The author compared the anteriorly displaced groups with control group. After surgical opening of the left rabbit TMJ space, cut the posterior attachment of the meniscus, and pushed it under the undercut area of the condyle head. Experimental groups were sacrificed by 1, 2, 4, 8 weeks after surgery. The samples were analysed with light microscope under T-B stain and electron microscope. The results were as follows: 1) The rabbit TMJ meniscus consisted of thick anterior and posterior band running different way, and comparative thin intermediate band runining antero-posteriorly. 2) Round oval shape chondrocyte-like cells were imbeded between the collagen fiber bundles and composed of proteoglycan granules, that showed metachromasia with toluidine blue, around the cell matrix. 3) Type II collagen fiber bundles in experimental group occured degenerative changes in organic patterns at 8 weeks, but those of type I collagen fiber bundles sustained longer, 4) The typical fibrocartilage of the rabbit TMJ meniscus was changed into fibrotic mode in process of time and showed the degenerative changes, which contained hyperplasia, calcification, resorption and hyalinization in the connective tissue. 5) The hyperplastic change of the synovial membrane in 4 week group and transitional change from fibrocyte to chondrocyte in cell type in 8 week group were observed. 6) The diameters of collagen fibers were diminished with the degenerative changes, the shape of the fibers became wavier and more nonorganic in running pattern and fiber bundle spaces widened.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.1
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• pp.14-20
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• 2013

Objectives: This study sought to evaluate the effect of simultaneous application of arthrocentesis and occlusal splint. Materials and Methods: A retrospective study of 43 patients (3 males, 40 females) whose symptoms had improved was conducted at the Department of Oral and Maxillofacial Surgery, Dong-A University Hospital between 2008 and 2010. Subjects were divided into three groups: Group A (17 patients with arthrocentesis and occlusal splints simultaneously applied), Group B (13 patients whose symptoms did not improve with occlusal splints, undergoing arthrocentesis after occlusal splint use for 8 weeks), and Group C (13 patients that only used occlusal splints). We compared these groups in maximum comfortable opening (MCO) and the visual analogue scale of pain and noise. Follow-up was performed at 1 week, 1 month, 3 months, and 6 months. Results: The improvement of symptoms was noted in all three groups, but Group A had a quicker improvement than the other groups, in terms of pain reduction and MCO increases. Conclusion: The simultaneous application of arthrocentesis and occlusal splints can reduce patient discomfort more quickly.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.1
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• pp.15-24
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• 1992

The purpose of this study was to analyze the mandibular asymmetry of the patients with the temporomandibular dysfunction. In this study, 20 dental students aged between 22 and 27 years, Chosun University, who did not possess any restoration and symptoms like the temporomandybular joint click, pain, and opening limitation of the mandible were selected as the normal group. And 80 patients who were analyzed into the patients with the temporomadibular dysfunction(TMD) were divided into group I as the internal derangement and group II as external derangement. Both the normal group and the TMD Group were faked submento-vertex cephalogram by routine methods after that the unilateral mandibular length(L) and the amount of mandibular asymmetry and deviation were measured and analyzed. The results were as follows : 1, Unilateral mandibular length(L) of the normal group and the TMD group were $112.7{\pm}10.20mm\;and\;102.65{\pm}8.10mm$ respectively (P<0.01). 2. The amount of mandibula asymmetry of the normal group and the TMD group were $5.95{\pm}4.63mm\;and\;5.68{\pm}4.35mm$ respectively (P<0.5). 3. The amount of mandibular deviation of the normal group and the TMD group were $6.00{\pm}4.07\;and\;4.67{\pm}3.40mm$ respectively (P<0.3). 4. In the TMD group, unilateral mandibular length(L) in the affected site and the non-affected site were $102.73{\pm}8.68mm\;and\;102.53{\pm}7.68mm$ respectively (P<0.5).

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.625-633
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• 2008

Recently, the participation, opening and joint ownership of the users are important issue. The users want professional and accurate information from web. But users often suffer from retrieving accurate information. Even though the users find information they want, it is not guaranteed that the information is reliable since there are too much information placed on the web. Thus, we propose the novel rank metric to promote reliability and efficiency in information retrieval. In order to verify our approach, we implement a web site based on the proposed rank metric for nonofficial medical science information. The proposed rank metric based on user's level. This is to give score of text through differential rate depending on the user's level. The proposed rank metric enhances the reliability of text which is reflecting the user's mental factor. Thus, this method can be used for enhancing the reliability of text.

• The Journal of Korean Academy of Prosthodontics
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• v.20 no.1
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• pp.83-91
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• 1982

The mandibular movement during mastication has been studied, however there is still much controversy, therefore the purpose of this study was to establish the fundamental data in order to provide the functional occlusion and information in prosthodontic treatment, and the diagnosis of temporomandibular joint disorder. The author analyzed the characteristics of the border and masticatory movements using the Mandibular Kinesiograph. The value, direction, deviation angulation of the border and masticatory movements were studied on the sagittal and frontal planes in 24 male subjects age of 22-28 without orofacial problems. The obtained results were as follows: 1. The values of border movement on the sagittal plane were an average of $25.81{\pm}5.14mm$ in vertical component and $24.37{\pm}3.76mm$ in ant-post component, and the posterior terminal hinge movement, $9.31{\pm}3.62mm$ in vertical component and $7.59{\pm}2.65mm$ in ant-post. component. 2. The distribution range of the masticatory movement within the border movement was an average of $19.2{\pm}12.81%$ of maximum ant-post, values and $55.5{\pm}16.1%$ of maximum values of border movement, and the movement path, for the most part, was directed to posterior deviation and ranged from 0.98 to 12.00mm, on an average of $5.15{\pm}3.49mm$. 3. On the frontal plane, a number of left and right deviation in 24 subjects was same, however, the right deviation was an average of $2.51{\pm}1.67mm$ compared with the left deviation. 4. On the frontal plane, the point of maximum lateral deviation was an average of $49.7{\pm}11.0%$ of maximum opening values. 5. The angulation between the terminal hinge movement path and the masticatory path was an average of $24.00{\pm}4.65$.

• 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.

• The Journal of Fisheries Business Administration
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• v.24 no.2
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• pp.17-53
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• 1993

Pusan is the largest fishing port in Korea, and deals with more than I million ton of fish catches annually, including catches of coastal and off-shore fisheries as well as those of deep-sea fishery. However, it hen had no fishing port facilities specialized fer deep-sea fishery since it started 30 years ago. Economic and physical losses resulting from this have teen enormous. Although fishing port facilities are a part of infra-structures built by Governments, the construction of them has been delayed due to financial difficulties of Central or local governments. To overcome this harsh situation to which deep-sea fishery cooperations faced, some cooperations have decided to construct fishing port facilities including fish-pier specialized for deep-sea fishery in Gamcheon port. The construction expenses of these facilities were financed by private funds to which they themselves jointly contributed. As a result, a fish-[pier, which has the capacity of serving one fishing vessel of 10, 000 ton or four of 5, 000 ton or four of 1, 000 ton at the same time, will be opened in here by 1994. The paper examines the master plan to revitalize the deep-sea fisheries industry in a deep depression with the opening of these physical facilities. The framwork of the plan is pursued in two different aspects, which are both hardware and software. In a hardware aspect, the plan in to develop Pusan into a city which is suitable for one of the best fishing ports in the world. That is, it is to develop the city into a place famous for sightseeing as well as the distribution and processing of fish-products centering around fish-piers. On the other hand, in a software aspet, it is regarding improvement of the distribution system of fish-products. One way to do that is to make up some deficiencies of the current system of a producers' joint sale. And the other is to establish an exchange of fish-products futures. Through these institutions, we could abrsorb speculative funds, which would otherwise be invested in speculation on fish-products, into productive investment opportunities, We believe that if the plan is realized, the deep-sea fishery in Korea will revive from a long-tasted depression and make progress to become one of the mai industries of Korea.