• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.448-456
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• 2011

Introduction: Condylar fractures are common in the maxillofacial region, comprising 29-40 percent of all mandibular fractures, accounting for about 20-62 percent). Previous studies reported that pediatric condylar fractures can cause disorders in facial growth and function, and the treatment methods have been controversial. Recently, conservative treatment has shown good results in skeletal growth and functional recovery but the conservative treatment of pediatric condylar fractures has shown unpredictable and undesirable results in some cases, such as facial asymmetry and temporomandibular joint disorder. This study examined the specific age groups and specific mandibular condylar fracture type in growing children treated conservatively in the past. Materials and Methods: Eighteen patients (10 men and 8 women) who received conservative treatment for unilateral condylar fractures in Dankook University Dental Hospital between 2000 to 2007 were followed up for a mean period of 7.2 years. Results: In the survey of 18 pediatric patients who received conservative treatment for condylar fractures, the incidence of temporomandibular dysfunction and growth disturbance was 45% and 35%, respectively. Conclusion: In all complications, the symptoms observed most frequently was mouth opening displacement of the mandible exceeding 2 mm. The other complications of functional and growth disturbance included facial asymmetry concentrated along specific condylar types. Complications including facial asymmetry and functional and growth disturbances showed an increasing tendency according to the specific fracture types. Functional and growth disturbances in the undisplaced condylar fracture type showed a lower incidence(P <0.05). Functional and growth disturbances differed according to the fracture type, which has poor relationship with articular fossa and condyle(P <0.05). Functional and growth disturbance in the cases of the high-level condylar fracture type showed a higher incidence(P <0.05). The functional and growth disturbances of the fracture types were similar in the fragment-contact and non-contact groups(P >0.05).

• Steel and Composite Structures
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• v.35 no.3
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• pp.439-447
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• 2020

This paper presents two sets of full three-dimensional thermoelastic finite element analyses of superimposed thermo-mechanically loaded Spar Wingskin Joints made with laminated Graphite Fiber Reinforced Plastic composites. The study emphasizes the influence of residual thermal stresses and material anisotropy on the inter-laminar delamination behavior of the joint structure. The delamination has been pre-embedded at the most likely location, i.e., in resin layer between the top and next ply of the fiber reinforced plastic laminated wingskin and near the spar overlap end. Multi-Point Constraint finite elements have been made use of at the vicinity of the delamination fronts. This helps in simulating the growth of the embedded delamination at both ends. The inter-laminar thermoelastic peel and shear stresses responsible for causing delamination damage due to a combined thermal and a static loading have been evaluated. Strain energy release rate components corresponding to the Mode I (opening), Mode II (sliding) and Mode III (tearing) of delamination are determined using the principle of Virtual Crack Closure Technique. These are seen to be different and non-self-similar at the two fronts of the embedded delamination. Residual stresses developed due to the thermoelastic anisotropy of the laminae are found to strongly influence the delamination onset and propagation characteristics, which have been reflected by the asymmetries in the nature of energy release rate plots and their significant variation along the delamination front.

• Journal of Distribution Science
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• v.14 no.10
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• pp.137-146
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• 2016

Purpose - Korean agriculture is facing internal and external environmental changes and the need for secure stable outlets. Active participation and mutually beneficial cooperation between enterprises and agricultural is necessary for a win-win situation. This study investigates the case for distribution cooperation and a cooperative system. To respond to the diverse needs of consumers and market reclamation, there is a need to analyze and categorize distribution cooperation. Research design, data, and methodology - A literature study, relevant interviews with enterprises, and meetings with local government practices were conducted. A survey frame was derived through the participation of agricultural enterprises and distribution cooperation models were categorized identifying win-win cooperation and best practices. It was organized on the basis of six best practice examples of distribution cooperation between industry and agricultural sectors, divided into three types: opening distribution channels, exporting cooperation, and developing new products. Results - An innovation management system that can adapt to environmental changes and problems of agriculture is necessary. A company has to supply high-quality agricultural products reliably to meet the preferences of consumers by introducing products that promote domestic market differentiation. In addition, consumers are choosing a variety of products that may include not only high quality products but also local products and safe products. The main areas of cooperation are the direct provision of agrifood raw materials to consumers. Next, would be to help agricultural sectors distribute and pioneer international markets. The ideal step for distribution cooperation is the joint investment in new products by business and agriculture. Conclusions - Agriculture and win-win cooperation with enterprises is in an early stage of social contribution. To implement a distribution cooperation model between business and agricultural sectors, it is crucial to establish a structured support system including joint councils. Additional requirements include strengthening agricultural capacities, creating a legal basis for provision, and producing a win-win cooperation environment. The promotion of win-win cooperation and agricultural enterprises needs to exist in various forms in order to establish a different type of incentive system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.2
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• pp.141-146
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• 2002

Purpose: Various treatment methods have been utilized for recurrent dislocation of the TMJ (temporomandibular joint). The purpose of this study is to define the effect of the eminectomy with discoplasty that had been performed in patients with TMJ luxation. Materials and Methods: Twenty patients (22 joints), whose diagnosis were TMJ dislocation were selected in 772 patients (871 joints) who had been underwent TMJ surgery between 1988 and 2000. The selected patients were divided into two groups. Group I (12 joints) was the habitual-luxation group which involves the recurrent TMJ dislocation patients. Group II (10 joints) was the open lock-history group which involves the patients who had more than two episodes of TMJ luxation and TMJ disorders. The history of TMJ luxation, maximum mouth opening and other TMJ signs and symptoms before and after surgery were reviewed. Results: In group I, one patient who had been underwent both TMJ operation had a intermittent locking, but it disappeared after post-operative 32 months. In group II, intermittent pain was present in one patient who had bruxism, but it was disappeared by splint therapy. No more TMJ dislocations and other pains were checked in other patients of group I and II. Conclusion: Eminectomy with discoplasty may be used to successfully treat the TMJ habitual luxation accompanied with abnormal condition of the disc-condyle complex.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.5
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• pp.375-380
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• 2009

Objective : Trauma has been a controversial issue although it has been considered to be a major factor for the temporomandibular disorder(TMD). We evaluated the relationship between macrotrauma or microtrauma and TMD. Methods : This study was performed in patients with TMD undergoing treatment at SNUBH from October 2006 to January 2007. Sixty one male patients and 166 female patients(total 227) were included and the average age was 34 years(ranging from 14 to 85 years). We investigated the possible etiologic factors, diagnosis and treatment with the review of medical records and radiography. Chronic pain, depression, somatic score(including pain item), somatic score(excluding pain item) were evaluated on the basis of diagnostic index from the Research Diagnostic Criteria on TMD. Results : Eighteen patients(7.9%) out of 227 patients suffered from TMD as a result of macrotrauma. Ninety four(41.4%) patients had microtrauma and six patients(2.6%) had both macro- and microtrauma(etiologic factor). The main symptoms included pain. joint noise and mouth opening limitation while the other symptoms were headache and tinnitus. The patients had suffered from TMD for average 41 weeks (ranging from 1 to 480 weeks). 116 patients took splint as a major treatment. As a prognosis, 19 patients(8.4%) recovered completely. 26(11.0%) had improvement and 181(80%) had persistent symptoms. 1 patient(0.4%) underwent an arthroplasty. Diagnostic index from RDC chart showed that macrotrauma was the highest score(except depression score) among the other etiologic factors. Conclusion : This study showed that macro- and microtrauma can be considered to be the major etiologic factors of TMD, which also affect the chronic, depression and somatic discomfort.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.231-236
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• 2006

Rheumatoid arthritis(RA) is an of autoimmune inflammatory systemic disease. It is characterized by uncontrolled proliferation of synovial tissue and a wide array multisystem comorbidities. The disease may involve any joint of the body, but often statrs in the peripheral joints. It was reported that more than 50% of RA patients exhibit clinical involvement of TMJ. This report is a case report of dental management and progression for 16 months in patients who had severe bony change in TMJ involved rheumatoid arthritis Dental management was included palliative treatment such as interocclusal splints, physical therapy, mouth opening exercise. Although it was progressed rapidly osteolytic bone change during follow-up, no more advanced occulsal change and improved symptom and jaw motion. Further investigations about rule of dentistry in TMJ involvement in RA maybe needed.

• Journal of Korea Port Economic Association
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• v.25 no.1
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• pp.271-292
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• 2009

Opening and regional economic integration are characteristic of global economic trends that have been made since the 1990s. Accordingly, all economic blocs of the world are largely reorganized into three poles, European Economic Bloc, American Economic Bloc and Northeast Asian Economic Block which are respectively led by EU, the United States and the rapidly emerging economic power, China. Considering this direction of global economy, the current status of Northeast Asia, China's unprecedentedly enormous port development project and Japan's introduction of an epoch-making port policy towards the restoration of its port competitiveness, Korea is urgently need to take its own initiatives and positive actions that can cope with the above situations. The purpose of this study is to propose ways of strategic cooperation for Korea-Japan joint development. For the purpose, this researcher provides the concept and preconditions of hub-port, investigates hub-port development strategies of rival companies in Northeast Asia and discusses the potential of the development of the Korea-Japan Strait Economic Zone which is located between Busan port and Japan's Honshu(Simonoseki port) and Kyushu(Kitakyushu port).

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.101-114
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• 2003

The purpose of this study was to examine the major kinematicak variance to Increase the club head velocity during the driver swing two PGA prp-golfers utilizing 3-dimensional Image analyzing linear velocity of the club-head during the impact quantiatively. To achive these purpose, two high speed camera in 120 field/s and one high-speed camera in 500 field/s were used in this study. The program made by Younghoo Kwon(1944) was used to analysis the digitalization of reference point, digitalization of joint venter, synchronization, calculation of 3-Dimensional coordinate by DLT method, and smoothing. Through this study, the conclusions are as follow. 1. During the drivel swing, in the percentile of the total time, two pro-golfer showed 0.925, 0.929 second from adress to top-swing, 0.236, 0.929 second from top-swing to impact. 2. During the driver swing, in the displacement of the center of the body, two pro-golfer showed 45.3, 45.23% from adress, 44.3, 44.24% front impact. 3. In the velocity variance, The maximum club-head velocity two pro-golfer showed 43.36, 43.24m/s respectively the down swing. The ball velocity showed 63.12, 63.06m/s. 4. In the rotational angle of the shoulder joint. two pro-golfer showed $-13.5,-13.53^{\circ}$, during the back swing respectively. Two subject adressed opening status og upper body. 5. In the rotational angle of the right knee angle showed $156.3,154.7^{\circ}$ from the adress.

• Journal of Oral Medicine and Pain
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• v.48 no.1
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• pp.31-36
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• 2023

This report presents the case of a 14-year-old male with rheumatoid arthritis (RA) in both temporomandibular joints (TMJs), in whom a bone scan and laboratory tests were used to confirm the diagnosis. The patient visited the Department of Orofacial Pain and Oral Medicine at the affiliation hospital with a complaint of a 1-year history of bilateral TMJ pain and sound. Clinical examination revealed bilateral TMJ and masseter muscle pain during mouth opening and palpation. Radiological examination revealed no significant morphological changes in either TMJ. The patient was prescribed medications at the first visit to address the pain, inflammation, and stiffness. A bone scan and laboratory tests were planned/scheduled for differential diagnosis between simple arthralgia and osteoarthritis. The bone scan revealed increased radiotracer uptake in both TMJs. The laboratory tests revealed a RA factor of 82.4 IU/mL, which is more than four times the normal range. The final diagnoses were bilateral TMJ early rheumatoid arthritis (ERA) and juvenile idiopathic arthritis. We created a stabilization splint and referred the patient to the Department of Rheumatology for further evaluation of the ERA. After fitting of the stabilization splint and giving instructions regarding its use, the patient has been receiving monthly follow-up checks for symptoms and undergoes follow-up blood tests every 3 months. About 14 months after the initial visit, the pain had significantly decreased from a Visual Analog Scale score of 5 to 1, and the RA factor decreased to 66.6 IU/mL. A regular follow-up check will continue until the end of growth.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.365-373
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• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.