• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.267-272
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• 2002

Pitting corrosion is a very common occurrence in marine structures. Therefore, the 3-D finite element analysis is carried out to determine the stress intensity factors at the pit depth and also at the surface of the pit. The pits are modeled as a part of sphere, based on the pit depth and the pit diameter as specified by the Ship Structural Committee. The pit depth and pit diameter are function of the percentage of pitting that the plate is subjected to. A dog-bone shaped specimen is subjected to different intensities of pitting and the stress intensity factors are determined under axial tensile loads.

• Transactions of Materials Processing
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• v.23 no.3
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• pp.145-150
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• 2014

Precision control of the slab is crucial for product quality and production economy in hot strip mills. The current study presents a new model for predicting width spread of a slab with a rectangular cross section during roughing. The model is developed on the basis of the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. This model incorporates the effect of process variables such as the shape factor and the ratio of width to thickness. We compare the results of this model to 3-D finite element (FE) process simulations and also to results from a previous study.

• Journal of Veterinary Clinics
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• v.20 no.4
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• pp.523-526
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• 2003

Three dimensional computed tomographic images were obtained in two cases with trauma. The first case of a 3 year-old male Maltese, with ataxia and head tilting due to head trauma was referred to veterinary medical teaching hospital, Seoul National University. Remarkable findings were not found on survey radiographs. With the help of three-dimensional reconstruction computed tomographic imaging, parietal and occipital bone fracture was identified. The second case of 4 month-old female Yorkshire terrier with left forelimb lameness was referred right after trauma. Survey radiography showed obvious incongruity of the elbow joint. Lateral and medial condyle of the left humerus fracture and lateral displacement of the left ulna were apparent in three-dimensional computed tomographic image. It was considered that three-dimensional computed tomography could be used as an aid modality for the exact evaluation of extends and degree of fracture as well as planning of orthopedic surgery.

• Transactions of Materials Processing
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• v.12 no.7
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• pp.668-674
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• 2003

Rigid-plastic finite element analyses on the deformation of slabs at various width reductions have been performed. By using commercial finite element code, dog-bone profile, crop profile and the longitudinal width profile after edging and Horizontal rolling have been analysed. The deformation behavior of slab for the heavy edger mill has also been compared with that for the sizing press. From the deformation analyses, it was found that the sizing press-horizontal rolling method is more efficient in width reduction than that of heavy edger mill-horizontal rolling. The results of finite element analyses fer the deformation of slab were well confirmed by the actual operational data. It was found that the amount of width variation after sizing and rolling is about 5∼10mm.

• Transactions of Materials Processing
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• v.28 no.2
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• pp.83-88
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• 2019

This paper introduces a new concept - on-line FE model, as applied to metal rolling. The new technology allows for completion of process simulation within a tiny fraction of a second without loss of high-level prediction accuracy inherent to FEM. The three steps of an on-line FE model design namely, process metamorphosis, mesh design, and process variable design, are described in detail. The procedure is demonstrated step by step through designing actual on-line models for the prediction of the dog-bone profile in edge rolling. The validity and prediction accuracy of the on-line FE models are analyzed and discussed.

• Transactions of Materials Processing
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• v.28 no.2
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• pp.89-97
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• 2019

In this paper, we examine the application of a new concept - on-line FE model in various metal rolling processes. This technology allows for completion of process simulation within a tiny fraction of a second without losing the high level of prediction accuracy inherent to FEM. The procedure is systematically demonstrated through the design of actual on-line models for the prediction of the width spread in horizontal rolling of the slab using a dog bone profile and horizontal rolling of the strip with a strip profile. The validity and the prediction accuracy of the on-line FE models were analyzed and discussed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.591-601
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• 2000

The objective of this study was to find out whether the unilateral distraction of mandible has an influence on temporomandibular joint and if it does, how significant the influence is. Four beagle dogs were used in this study. Each dog had two implants placed into the left mandible. The mandible was distracted for 14days with an distraction device as an amount of 0.75mm, twice per day after osteotomy between two implants. Each animals were sacrificed at the second, fourth, sixth and eighth week after the total distraction amount of 10.5mm were gotten. Upon embedding and staining, the specimens were evaluated with a light microscope. The results were as follows. 1. For the second week group, the articular cartilage and osteoid seam of temporal bone and condyle were relatively well maintained. There were not any significant differences between distraction side and non distraction side. 2. For the fourth week group, the periosteal reaction was activated and the articular cartilage and osteoid seam of temporal bone and condyle were severely thickened - especially at posterior portion of distraction side. This findings revealed that the unilateral distraction forces has more influence on distraction side than on non distraction side, and on posterior portion than on anterior portion. 3. For the sixth and eighth week group, the thickness of meniscus in distraction side gradually recovered to the initial level. The thickened articular cartilage and osteoid seam of temporal bone and condyle were decreased in distraction side and showed relatively stable in non distraction side. From this results, we suggest that several considerations are required such as using an occlusal splint, maintaining the stability of bone distraction device and evaluating bone distraction rate to minimize the damages of temporomandibular joint tissues in early stage of distraction side.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.301-310
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• 2003

The purpose of this study is to evaluate the biocompatibility and the biorsorbability of several types of calcium polyphosphate made through change of manufacturing process for 12 month. To solve limitation of calcium phosphate, we developed a new ceramic, Calcium Polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP blocks were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$ and then milled to produce CPP powder. CPP powder, CPP block, and CPP granules added with $Na_2O$ were implanted in extraction sockets and histologic observation were performed at 12 months later. Like 3 months results, histologic observation at 12 months revealed that CPP matrix were mingled with and directly apposed to new bone without any adverse tissue reaction, CPP powder show direct bony contact, but new bone formation and fibrous tissue encapsulation showed in CPP block. 10% $Na_2O$ CPP granules show more inflammatory cells infiltration around graft materials compared at 3 month, but 15% $Na_2O$ CPP granules show less. This result revealed that regardless of addition of $Na_2O$, CPP had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ help biodegradation but optimal concentration of $Na_2O$ and other additive component to increase degradation rate should be determined in further study.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.2
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• pp.129-136
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• 1993

The purpose of this study is to evaluate whether the ashed tooth powder is utilized as an alternative material of the implant. For this purpose the author performed the experimental study to investigate the tissue response of sintered toothash and its histocompatibility. Bony defects to expose the body of marrow, $1{\times}1cm$ in size, were created in the right and left mandibular body of mature dog, and then the ashed tooth powders were filled in right side and the blood clot was filled in the left side as an control. The dogs were sacrificed at 4th, 7th, and 16th week after implantation and histologic examination was performed. The results of this study were obtained as follows : 1. Any inflammatory response was not noted after implanting of the ashed tooth powder during the whole experimental period. 2. At 4th week, ashed tooth powders were surrounded by mature connective tissue. And we could observe hydroxyapatite crystal structure within the ashed tooth powder. 3. At 7th week, we could observe that macrophage phagocyted the small granules of ashed tooth powders. 4. At 16th week, the union with host bone by growth of new trabeculae was observed. And there were remnants of ashed tooth power within some of new trabeculae.

• Journal of Veterinary Clinics
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• v.31 no.2
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• pp.133-136
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• 2014

An 8 kg, 9-month-old castrated male Shiba Inu presented with a history of intermittent bilateral hind limb lameness. On examination, grade III medial patellar luxation of the bilateral hind limbs was diagnosed. A novel surgical method involving relatively noninvasive tibial tuberosity transposition was used to restore normal alignment of the quadriceps mechanism. The procedure involved an incision on the medial cortical bone of the tibial tuberosity along the tibial crest and placement of a cortical screw on the medial side of the tibial crest to laterally transpose the tibial tuberosity. Lameness and patellar luxation of bilateral hind limbs were improved at a 3-month postoperative examination. This technique could be considered an effective treatment for medial patellar luxation in skeletal immature patients.