• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.98-129
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• 1995

The purpose of this study was to evaluate how mandibular implant-supported fixed complete prosthesis, implant and mandible responded mechanically, according to curvature of arch, number and location of fixture, and amounts of load. The shape of mandibular arch was tapered or square form and, 4 or 6 fixtures were implanted in each arch model. A vertical load of 10kg was applied at the center of prosthesis and a vertical load of 20kg was applied at the location of the 10mm or 20mm cantilever posterior to the most distal implant. Three-dimensional finite element analysis was performed for stress distribution and deflection using commercial software(ABAQUS program) for Sun-SPARC Workstation. The results were as follows : 1. The case square arch form was more stable to compare with that of tapered arch form in respect of stress distribution and displacement under vertical load on the center of prosthesis. 2. 6-implants cases were more stable than 4-implants cases for decreasing bending torque under vertical load on the center of prosthesis. 3. Under vertical load on cantilever extension, the case of 10mm long cantilever was more stable than that of 20mm long cantilever in respect of stress distribution and displacement. 4. Under vertical load on cantilever extension, 6-implants cases had a tendency to reduce displacement and to increase the reaction force of supporting point due to increasing of the bending stiffness of the prosthesis than 4-implant case. 5. When the ends of 10mm or 20mm long cantilever were loaded, the most distal implant was under compressive stress but the second most distal implant was under the highest tensile stress and the remaining implants were under varying tensile stress. 6. Because 6-implants cases had smaller displacement than 4-implants cases, 6-implants cases were more favorable in respect of prevention of screw loosening under repeated loadings.

• Korean Journal of Plant Taxonomy
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• v.39 no.4
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• pp.309-314
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• 2009

Two naturalized species, Glyceria declinata $Br{\acute{e}}b$. and Puccinellia distans (Jacq.) Parl. are herein newly reported from Korea. Glyceria declinata, 'Yu-Reop-Yuk-Jeol-Bo-Ri-Pul', was found along the Seomjin River, Gurye-eup, Gurye-gun, Jeollanam-do, as well as along the Gwangjucheon River, Sa-dong, Dong-gu, Gwangju. It is distinguished from G. acutiflora by spikelets 15-20mm long and obtuse lemma. Puccinellia distans, "Cheo-Jin-Mi-Kku-Ri-Gwang-I", was found in Yeongjong Island, Incheon, Yongyu Island, Incheon and Chojijin, Ganghwa-gun. It is distinguished from P. nipponica by lemmas 1.8-2.5mm long, ligule 1-2mm long and the lower branches of panicle usually reflexed after anthesis.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.521-528
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• 2005

The purpose of this research is to find out the degree of cartilage regeneration by inserting the atelo-collagen scaffold obtained from dermis of a calf on cartilage defect site. Dissection underneath the perichondrium by the periosteal elevator on both side of ears of six New Zealand white rabbits were made to expose the cartilage, leaving pairs of circular holes 3, 6, 9 mm width with punches. One hole was left for a control, and on the other hole atelo-collagen scaffold of the same size was transplanted. In postoperative 1, 2, 4 weeks, the tissues were dyed. The length of long axis of neocartilage was measured through an optical microscope with a 0.1 mm graduation at original magnification, ${\times}40$. In the first and second week, both group showed no sign of cartilage regeneration. In the fourth week, regeneration on marginal portions was observed on all groups and the average values of length of long axis of neocartilage according to defect size were as follows: In the cases with 3mm defect, it was $0.85{\pm}0.30mm$ in the control group, and $1.85{\pm}0.38mm$ in the graft group; in the cases with 6 mm defect, $1.33{\pm}0.58mm$ in the control group, and $2.25{\pm}0.46mm$ in the graft group; and in the cases with 9 mm defect, $2.33{\pm}0.77mm$ in the control group, and $4.47{\pm}1.39mm$ in the graft group. This means that the collagen scaffold has an influence on the regeneration of neocartilage. But the relative ratio of the length of neocartilage to cartilage defect size was not significant in the statistics.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.325-328
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• 2008

This study is to investigate experimentally the long-term deflection of concrete beams with glass fiber reinforced polymer (GFRP) reinforcing bars subjected to the sustained flexural load for periods of up to 6 months. A total of four beams were tested. All beams were designed with net span of 2,700 mm and rectangular cross-section of 200 mm width and 300 mm depth. From the test results the time-dependent deflection of concrete beams with GFRP bars was about 40 to 70% of the initial deflection. As well as this paper compares the long-term deflection calculated by 440.1R-06 design guide and that of tested beams. The comparison indicated that the calculated long-term deflection overestimate the observed long-term deflection of concrete beams with FRP rebars.

• Steel and Composite Structures
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• v.32 no.5
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• pp.571-582
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• 2019

This study aimed to assess the feasibility on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell. First, 5-m-wide and 15-m-long 9%Ni steel plates were test manufactured from a steel mill and specimens taken from the plates were tested for strength, toughness, and flatness to verify their performance based on international standards and design specifications. Second, plates with a thickness of 10 mm and 25 mm, a width of 4.8~5.0 m, and a length of 15 m were test fabricated by subjecting to pretreatment, beveling, and roll bending resulting in a final width of 4.5~4.8 m and a length of 14.8m with fabrication errors identical to conventional plates. Third, welded specimens obtained via shield metal arc welding used for vertical welding of inner tank shell and submerged arc welding used for horizontal welding were also tested for strength, toughness and ductility. Fourth, verification of shell plate material and fabrication was followed by test erection using two 25-mm-thick, 4.5-m-wide and 14.8-m-long 9%Ni steel plates. No undesirable welding failure or deformation was found. Finally, parametric design using wide and long 9%Ni steel plates was carried out, and a simplified design method to determine the plate thickness along the shell height was proposed. The cost analysis based on the parametric design resulted in about 2% increase of steel weight; however, the construction cost was reduced about 6% due to large reduction in welding work.

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.2
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• pp.19-27
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• 2012

Structural insulated panels, which are structurally performed panels consisting of a plastic insulation bonded between two structural panel facings are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. By now, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to suggest fundamental reports such as racking resistance, axial capacity, transverse load capacity, and lintel load capacity for SIPs. Test results showed that maximum load was 44.3kN, allowable load was 14.7kN for racking resistance, and that maximum load was 137.6kN, allowable load was 37.4kN/m for axial compression capacity. For transverse load capacity, test results showed $10.3kN/m^2$ of maximum load, $3.4kN/m^2$ of allowable load. For lintel load capacity for SIPs dependent to lengths, allowable loads were 20.4kN for 600mm long lintel, 23.9kN for 1,200mm long lintel, 19.3kN for 1,800mm long lintel, and 2,400mm long lintel had 14.1kN of allowable load. In the near future, when the allowable load for wall application is established, SIPs is considered to substitute the existent post-and-lintel construction to bearing wall structure.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.561-566
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• 2001

A long bar impact test to alumina plates(AD 85 and AD 90) was carried out by using fabricated impact testing apparatus. The apparatus adopting a long bar of 2.1m in length made it possible to measure directly the applied impact force to the specimen during bar impact. The dimension of specimens was $33{\times}33mm$ and thickness was 3.4mm. Confinement of D2=18mm outer diameter and D1=10.5mm inner diameter was used to provide contact pressure to the specimen. Contact pressure of p=100 or 200MPa was applied to specimen before impact test. Damage caused in those cases were compared with the case of without contact pressure. The damage of specimen was different depending upon the pressure level of confinement. The existence of confinement had suppressed the development of radial cracks from the bottom of specimen and reduced the extent of damage as compared with cases without contact pressure(p=0MPa). Because the application of contact pressure to the specimen increased the apparent flexural stiffness of specimen during bar impact, it had produced the change of developed damage in the specimen; from the radial cracks to the local contact stress dominant damage. It would contribute to the improvement of the ballistic property in ceramic plates.

• Journal of Chest Surgery
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• v.32 no.10
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• pp.916-923
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• 1999

Background: Many institutes are interested in lung metastatectomy than before because of the improved long term survival, low mortality, and low morbidity after lung metastatectomy. However, prognostic factors affecting long term survival are controversial. We attempt to analyze the prognostic factors affecting retrospectively by comparing the results of lung metastasectomy. Material and Method: Between Jan. 1990 and Dec. 1997, 74 operations were taken in 63 patients with pulmonary metastases in various primary sites. We analyzed the postoperative long term survival according to sex, cell type, laterality, disease free interval(DFI), operation, the number of metastases, and the size of the largest metastasis. Result: There were 27 male and 36 female patients. Sex did not appeared to affect survival time(p=0.849). The primary tumor was carcinoma in 32, sarcoma in 28, and others in 3. Cell type, considering carcinoma and sarcoma, did not relate to survival time(p=0.071). DFI had no influence on the outcome(p=0.902). The type of operative procedure had no influence on the outcome(p=0.556). The laterality of metastases, 47 unilateral(74.6%) and 16 bilateral(25.4%), had no influence on the outcome(p=0.843). The number of metastases excised(one, two or three, four or more) did not appear to affect survival(p=0.263). The size of largest metastasis(<=10mm, 11mm-30mm, and >30mm) did not appear to affect survival(p=0.751). Previous factors were evaluated in both the carcinoma and sarcoma patients respectively. DFI was the only significant prognostic factor in metastatic lung sarcoma(p=0.0026). Conclusion: Survival was not related to sex, cell type, laterality, DFI, operative procedure, number of metastases, nor the size of the largest metastasis. DFI was related to the survival time in sarcoma group but further study is needed.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.59.3-59.3
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• 2019

Very Long Baseline Interferometry (VLBI) is a special technique which can provide high angular resolutions of milliarcsecond and sub-milliarcsecond sales in radio astronomical observations. Recently, the mm/sub-mm VLBI observations becomes more widely available and related activities are increasing accordingly. In this talk, I'll introduce ongoing global mm-VLBI activities and EHT collaboration and our (Korean) contributions to them.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.309-313
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• 2001

Life cycle and host plants of Scotinophara lurida(BURMEISTER) were studied from 1999 to 2001. Egg of S. lurida was oval-shaped with light-gray in color. Nymphs were reddish brown, dark brown, and brown, and the body was 1.19~7.24mm long, depending on their developmental stages from the 1st to the 5th instar. Adults were black and the body were 9.34mm and 8.47mm long in female laid 30.7 eggs in average for its life span. Developmental period was 4.3 days for eggs, and 45.8 days for nymphs. Total 9 host plant species was identified by the greenhouse observation in Chungbuk province.