• Journal of the Korean Arthroscopy Society
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• v.7 no.1
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• pp.92-95
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• 2003

A 34-year-old man with ACL total rupture due to slip down injury, had received ACL reconstruction using autogenous hamstrings tendon with cross-pin femoral fixation. Postoperative course was as usual. But postoperative 3 months later, he complained posterolateral knee pain, recurrent effusion and mild instability. He was managed repeatitive aspiration and nonsteroid antiinflammatory drugs but was failed to relieve symptoms & signs. In CT scans, perforation of posteromedial femoral cortex of lateral femoral condyle was found. In second look arthroscopy, two pieces of broken femoral cross pin were found in between tibiofemoral Joint which was badly injured cartilage. We considered malposition of pins was the main cause of failure. We propose that femoral tunnel must be made more acute angle and femoral cross-pin guide must be positioned more external rotation 10-20 degree than transepicondylar axis made confirm the cross-pin tunnel position in order to avoid posterior cortex perforation and early failure.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.66-76
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• 2008

Recently, demands for the structural uses with domestic Japanese larch and SPF(spruce-pine-fir) lumber from North America have been increased. Shear properties of nailed joints that are the most simple and optimum fastening method in wooden constructions, especially in light frame construction. For the nailed joints, in North America and Japan, a number of basic and practical studies have been performed. The shear behaviors for the double nailed joint with variations of member and its direction, were examined. Shear properties of the shear specimens with SPF stud showed more remarkable variation than larch glulam and larch stud. Furthermore, the relationships between slip modulus and strength are not coincided in every case.

• Steel and Composite Structures
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• v.23 no.6
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• pp.727-736
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• 2017

The application of carbon fiber reinforced polymer (CFRP) in steel structures primarily includes two categories, i.e., the bond-critical application and the contact-critical application. Debonding failure and buckling failure are the main failure modes for these two applications. Conventional electrometric techniques may not provide precise results because of the limitations associated with single-point contact measurements. A nondestructive full-field measurement technique is a valuable alternative to conventional methods. In this study, the digital image correlation (DIC) technique was adopted to investigate the bond behavior and buckling behavior of CFRP-steel composite members. The CFRP-to-steel bonded joint and the CFRP-strengthened square hollow section (SHS) steel column were tested to verify the suitability of the DIC technique. The stereo-DIC technique was utilized to measure continuous deformation. The bond-slip relationship of the CFRP-to-steel interface was derived using the DIC data. Additionally, a multi-camera DIC system consisting of four stereo-DIC subsystems was proposed and applied to the compressive test of CFRP-strengthened SHS steel column. The precise buckling location and CFRP delamination of the CFRP-strengthened SHS steel column were identified. The experimental results confirm that the stereo-DIC technique can provide effective measurements for investigating the behaviors of CFRP-steel composite members.

• Journal of the Earthquake Engineering Society of Korea
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• v.26 no.2
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• pp.71-82
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• 2022

This paper presents the effect on the inelastic behavior and structural performance of concrete and filled steel pipe through a numerical method for reliable judgment under various load conditions of the CJS composite structural system. Variable values optimized for the CJS synthetic structural system and the effects of multiple variables used for finite element analysis to present analytical modeling were compared and analyzed with experimental results. The Winfrith concrete model was used as a concrete material model that describes the confinement effect well, and the concrete structure was modeled with solid elements. Through geometric analysis of shell and solid elements, rectangular steel pipe columns and steel elements were modeled as shell elements. In addition, the slip behavior of the joint between the concrete column and the rectangular steel pipe was described using the Surface-to-Surface function. After finite element analysis modeling, simulation was performed for cyclic loading after assuming that the lower part of the foundation was a pin in the same way as in the experiment. The analysis model was verified by comparing the calculated analysis results with the experimental results, focusing on initial stiffness, maximum strength, and energy dissipation capability.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.190-198
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• 2018

In recent years, non-welded building hardware has been installed by bolt assembly is used. The non-welded building hardware method can reduce accidents caused by welding, and can be constructed by bolt assembly, which can reduce labor costs and shorten the construction period. However, there is a need for a method to compensate for the occurrence of buckling at the time of construction. The purpose of this study is to evaluate the behavior of joints between steel pipe and fastener and to evaluate the behavior of joints of non-welded and welded hardware frame. As a result, it was found that the foundation steel structure without welded joints was deformed to a rotation angle of member much larger than the allowable interlayer displacement angle 0.01 to 0.02 required according to the seismic load rating in the seismic load resistance system.

• The Journal of the Petrological Society of Korea
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• v.20 no.4
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• pp.173-189
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• 2011

Basic to acidic dykes and systematic joints are observed pervasively in the Jukbyeon-Bugu area, Uljin, east Korea. In order to classify the dykes and joints and to determine the relative chronology, their geometries, kinematics, and cross-cutting relationships, and the petrography and geochemistry of dykes are synthetically analyzed. Based on the orientations and cross-cutting relationships of 144 dykes (137 basic and 7 acidic dykes) and 370 systematic joints, three basic dike swarms (M-10, M-80, and M-100), one acidic dyke group (AD), and four joint sets (J-10, J-40, J-80, and J-150) are classified. Some of the J-150 joints reactivated as dextral strike-slip fault are recognized in the field and named as F-340R. According to petrographic, geochemical, and occurrence features in the field, M-80 and M-100 dykes have originated from a co-magma and intruded under the same stress field, even though they have intruded through different passages, preexisting fractures and new fractures created by magmatic pressure, respectively. And the relative chronology of dyke swarms and joint sets in the study area is determined as follows : ${\rightarrow}$ ${\rightarrow}$ ${\rightarrow}$ ${\rightarrow}$ ${\rightarrow}$ . And the M-80 (M-100) and M-10 dyke swarms intruded under NNE-SSW and NW-SE trending horizontal minimum stress fields, respectively. According to a synthesis of the results of the previous and this studies, the M-80, M-10, and F-340R are interpreted to have been formed about 64-52 Ma, Eocene~Oligocene, and Miocene, respectively.

• Journal of Korean Foot and Ankle Society
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• v.16 no.2
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• pp.94-100
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• 2012

Purpose: The purpose of this study is to analyze the clinical features of distal tibia fractures and to evaluate the treatment outcomes of minimally invasive plate osteosynthesis (MIPO). Materials and Methods: From January 2004 to December 2009, 84 cases of 81 patients treated with plate fixation for distal tibia fracture were enrolled in this retrospective review. We investigated age, sex, injury mechanism, fracture patterns, and complications, and the clinical features were analyzed. To evaluate the treatment outcomes of MIPO, we divided into two groups. MIPO group consisted of 55 patients were treated with MIPO technique and conventional group consisted of 18 patients were treated with open reduction and internal fixation with conventional anterolateral plating. The results were compared between two groups by assessing bony union time, operation time, amount of blood loss, range of ankle motion, clinical score by American Orthopaedic Foot and Ankle Society (AOFAS) score, and post-operative complications. Results: The mean age of 81 patients with distal tibia fracture was 54.8 years. According to AO classification, A1:2:3 were 16, 20, 16 patients, B1:2:3 were 2, 8, 7, C1:2:3 were 1, 3, 11 patients. According to injury mechanism, slip down injury was patients, traffic accident was 26, fall from height injury was 14 patients respectively. The type A fractures were lower energy trauma and more older patients. The type C fractures were higher energy trauma and younger patients. MIPO group was better than conventional group in operative time, blood loss, bony union time, and ankle joint motion. In complications, MIPO group showed no nonunion and infection, one malunion, one skin necrosis, nine skin irritations, and one screw breakage. Conventional group showed two nonunion, four infections, two skin necrosis, and one metal failure. Conclusion: Distal tibial fractures caused by low energy trauma were on the increase. Minimal invasive plate osteosynthesis was shorter bony union time and operation time, less blood loss, and larger ankle motions than conventional open reduction and plate fixation.

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.207-223
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• 1995

A new medical delivery system which regulated outpatient department(OPD) use from tertiary care hospitals was adopted in 1989. Under the new system, patients using tertiary care hospital OPD without referral slip from clinics or hospitals could not get any insurance benefit for the services received from the tertiary care hospital. This study was conducted to evaluate the Patient Referral System(PRS) with respect to health care expenditures and utilization. Two data sets were used in this study. One was monthly data set(from January 1986 to December 1992) from the Annual Report of Korea Medical Insurance Corporation(KMIC). The other was monthly joint data set composed of personal data of which 10% were selected randomly with their utilization data of KMIC from January 1988 to December 1992. The data were analyzed by time-series intervention model of SAS-ETS. The results of this study were as follows: 1. There was no statistically significant changes in per capita expenditures following PRS. 2. Utilization episodes per capita was increased statistically significantly after implementation of PRS. The use of clinics and hospitals increased significantly, whereas in tertiary care hospitals the use decreased significantly immediately after implementation of PRS and increased afterwards. 3. Follow-up visits per episode were decreased statistically significantly after implementation of PRS. The decrease of follow-up visits per episode were remarkable in clinics and hospitals, whereas in tertiary care hospitals it was increased significantly after implementation of PRS. 4. There was no statistically significant changes in prescribing days per episode following PRS. Futhermore, clinics and hospitals showed a statistically significant decrease in prescribing days per episode, whereas in tertiary care hospital it showed statistically significant increase after implementation of PRS. 5. Except high income class, the use of tertiary care hospitals showed statistically significant decrease after implementation of PRS. The degree of decrease in the use of tertiary care hospitals was inversely proportional to income. These results suggest that the PRS policy was not efficient because per capita expenditures did not decrease, and was not effective because utilization episodes per capita, follow-up visits per episode. and prescribing days per episode were not predictable and failed to show proper utilization. It was somewhat positive that utilization episodes per capita were decreased temporarily in tertiary care hospitals. And PRS policy was not appropriate because utilization episodes per capita was different among income groups. In conclusion, the PRS should be revised for initial goal attainment of cost containment and proper health care utilization.

• Composites Research
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• v.37 no.3
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• pp.238-245
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• 2024

In this study, as part of the development of a monitoring system for the efficient maintenance of steel pipes, an experimental study was conducted to evaluate the performance of steel pipes treated with modified polyethylene coating. In the case of the conventional mechanical pre-coating method, there was a deterioration in polyethylene adhesion during expansion testing, which led to the application of a chemical pre-treatment process using a calcium-mixed phosphate zinc film to resolve this issue. SEM and EDX analyses showed that the densest structure was observed at a Zn/Ca ratio of 1.0, and improved heat resistance compared to the conventional method was confirmed. Additionally, to prevent coating detachment during expansion, an evaluation of adhesion and elongation was conducted on steel pipes with modified polyethylene coating, incorporating materials such as elastomers based on maleic anhydride grafting, metal oxides, blocking agents, and slip agents. Experimental results showed that the specimen (S4) containing all modified materials exhibited more than a 25% performance improvement compared to the specimen (S2) containing only metal oxides. Lastly, the development and performance evaluation of wedge-shaped socketing and pressing wheels, which are part of the pipe fixing accessories, were conducted to prevent surface coating damage on the completed pipes.

• The Journal of the Petrological Society of Korea
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• v.14 no.2 s.40
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• pp.108-115
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• 2005

Gyeonggi metamorphic complex in the Gwangju area include banded biotite gneiss and quartzofeldspathic gneiss. Detailed structural analysis suggests that structural elements in the study area were formed by at least five phase of deformations. Penetrative compositional foliations(S1) formed in the banded gneiss during the first metamorphism and deformation (D1). After intrusion of plutonic rocks, the second deformation (D2) produced S2 foliations in the banded gneiss and quartzofeldspathic gneiss during the second metamorphism. D3 structures are represented by isoclinal folds (F3) whose axial surfaces are parallel to S3 foliations. The N-S oriented shortening (D4) was accommodated by closed upright F4 fold with about 100m of axial surface separation. F4 fold is refolded by regional F5 folding resulting in different orientation and fold style of F4 fold according to the position of F5 fold. The F4 fold with tight interlimb angle is subparallel to the axial surface (north-south) of F5 fold in the core of the F5 fold. In contrast the F4 fold trends northeast in the western limb and northwest in the eastern limb of F5 fold. The interlimb angle is larger in the limbs than that in the core of F5 fold. The trace of foliations is constrained by mainly F4 and F5 folds. Joint fanning around fold is developed in the limbs of F5 fold and bc joints are dominant in the hinge area of F5 fold. A strike-slip fault had developed in tile central part of the study area after F5 folding. The orientation of joint and foliation is rotated anticlockwise about $15^{\circ}$ by the landslide occurred during the Quaternary.