• Journal of the Korean Geotechnical Society
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• v.36 no.8
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• pp.35-47
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• 2020

For permanent anchors used for slope reinforcement, bearing capacity and durability should be secured during the period of use. However, according to recent domestic and foreign studies, phenomena such as tension fractures, damage to anchorages, deformation and damage to slope and reduction of residual load over time have been reported along the long-term behavior of the anchors. These problems are expected to increase in the future, which will inevitably lead to problems such as increasing maintenance costs and relevant facility collapse. It is necessary to improve maintenance procedures and methods of ground anchors more practically. In this study, the problems and limitations of domestic maintenance methods were analyzed by conducting a literature study, and the measurement data of load cells installed on the install ground anchors were analyzed to determine the change in the residual load with regard to the elapsed date of the anchors. Based on the results, the effect of the construction conditions of anchors and the soil compositions on the increase and decrease of load were identified.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.22-26
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• 2013

The purpose of this study was to improve the design of a mooring line by attaching a lumped mass to it on the seabed. A numerical analysis of the redesigned mooring system is performed to analyze the effect of the weight of the attached lumped mass using the commercial software Orcaflex. The ultimate tension of the mooring system with the lumped mass is compared with that of a bare mooring line in the original design. An appropriately designed weight for the lumped mass is found to induce a critical lifted point in the mooring line by floater motion in the ultimate condition to move toward the floater position from the anchor point, while maintaining a similar safety factor for the mooring line. On the other hand, it is shown that excess weight for the lumped mass induces snapping in a mooring line, resulting in low safety factor for the mooring system. The distance between lumped weights is shown to be a minor parameter affecting the safety of a mooring line, although a shorter line has an advantage from an economic point of view. Using the optimal weight for the lumped mass attached to the mooring line on a seabed reduces the mooring line length and installation area occupied by a mooring system under real sea conditions.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.95-99
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• 2013

We introduce arthroscopic Bankart repair technique using antegrade suture passer that can effectively restore detached anteroinferior capsulolabral complex for shoulder anterior instability. After diagnostic arthroscopy is performed using posterior, anteroinferior and anterosuperior portals, we confirm Bankart lesion and perform debridement and decortications of anteroinferior glenoid edge and neck. Suture anchor is inserted through anteroinferior portal at 2 mm medial side of glenoid edge (4:30 direction). Scorpion$^{TM}$ loaded suture is directly advanced to detached and retracted anteroinferior capsulolabral complex and the suture is passed at 10~15 mm medial side of detached anteroinferior capsulolabral complex (5:30 direction). The suture is retrieved by Scorpion's hook and then is tied using samsung medical center (SMC) sliding knot technique. Then suture anchors are serially inserted (2:30, 3:30) and capsulolabral complex repair is performed using suture hook and suttle-relay technique. This technique that can obtain anatomical restoration of anteroinferior glenohumeral ligament with proper tension is useful technique to reduce postoperative recurrence and makes it possible for less experienced surgeons.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.75-82
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• 2015

An experimental study has been carried out to examine development length effects for high strength headed deformed bars. Current design codes limit the specified yield strength of headed bars to 400 MPa. Such the limit is due to the lack of experimental studies on headed bars made of high strength materials. Thus a test program was planed with headed bars with the yield strength of 600 MPa. The threaded head type with head shapes of round plate and circular cone was selected in this study. The experimental variables were development length, number of bars, and head shape. Specimens were classified into L-type and S-type depending on the development length. The development length of L-type was computed according to the design code without considering the limit. S-type specimens had shorter development lengths than the L-type. Further classification was made depending on the shape of heads. A-types have the head shape of round plate and B-types have the shape of circular cone. Three L-type specimens were fabricated with the variable of number of bars (1, 2, and 3). Four specimens for each of SA and SB types were made with development lengths of 50%, 45%, 40%, and 35% compared with L-type. Pullout tests was carried out with 11 specimens. The test results were compared with computed strengths with the design code equations (Appendix II). Based the current studies, it can be said that high strength headed deformed bars used in this study be able to provide such strengths computed with the current design code without considering the yield strength limit.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.19-29
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• 2009

In this study, a numerical analysis was performed to predict the sequential behavior of anchored retaining wall where the failure accident took place, and verified accuracy of prediction through the comparisons between prediction and field measurement. The emphasis was given to the wall behaviors and the variation of sliding surface based on the two different methods of elasto-plastic and finite element (shear strength reduction technique). Through the comparison study, it is shown that the bending moment and the soil pressure at construction stages produce quite similar results in both the elasto-plastic and finite element method. However, predicted wall deflections using elasto-plastic method show underestimate results compared with measured deflections. This demonstrates that the elasto-plastic method does not clearly consider the influence of soil-wall-reinforcement interaction, so that the tension force (anchor force and earth pressure) on the wall is overestimated. Based on the results obtained, it is found that finite element method using shear strength reduction method can be effectively used to perform the back calculation analysis in the anchored retaining wall, whereas elasto-plastic method can be applicable to the preliminary design of retaining wall with suitable safety factor.

• Archives of design research
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• v.18 no.4 s.62
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• pp.53-64
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• 2005

The emergence of new communication media, digital, is something of a wonder, as well as a cultural tension. The industrial technologies that dramatically expand human abilities are being developed much faster than the speed of adaptation by humans. Without an exception, it creates new contents and form of the culture by shaking the very foundation of the notion about human beings. Korean broadcasting environment has stepped into the era of multi-media, multi-channel as the digital technology separated the media into network, cable, satellite and internet. In this digital culture, broadcasting, as a medium of information delivering and communication, has bigger influence than ever. Such changes in broadcasting environment turned the TV viewers into new consumers who participate and play the main role in active communication by choosing and using the media. This study is trying to systemize the question about the core identity of broadcasting through brand as the consumers stand in the center of broadcasting with the power to select channel. The story schema theory can be applied as a cognitive psychological tool to approach the active consumers in order to explain the cognitive processes that are related to information processing. It is a design with stories, which comes up as a case of a brand's story telling. The range of this study covers the current issue and educational programs in network TV during the period of May and August of year 2005. The cases of Korean and foreign programs were compared by the station each program is broadcasted. This study concludes that it is important to take the channel identity into the consideration in the brand strategy of each program. Especially, the leading programs of a station must not be treated as a separate program that has nothing to do with the station's identity. They must be treated to include the contents and form that builds the identity of the channel. Also, this study reconfirmed that building a brand of the anchor person can play as an important factor in the identity of the program's brand.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.16-24
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• 2012

Purpose: This study was designed to investigate the rate of incidence, location and the clinical value of the rotator cuff retear by analyzing MRI scans, which was taken after an arthroscopic rotator cuff repair. Materials and Methods: This study included a total of 109 patients, who underwent a shoulder MRI scan after an average of 10.6 months later from the arthroscopic rotator cuff repair. We only defined the 'retear' when the Sugaya type IV and V was observed in the sagittal section of the MRI. The location of the retear was divided into the medial and lateral areas by the site, which was 1 cm medial to the anchor insertion. We investigated the incidence rate and the location of the retear, in terms of the age, sex, initial tear size and the suture method. Also, we compared the functional score of the retear group and the non-retear group, after an average of 13.9 months follow-up. Results: There were 38 of the 109 patients that showed the rotator cuff retear. Of these patients, 25 were male patients, and 13 were female patients. Of the 38 patients with the rotator cuff retear, 21 patients were included in the <3 cm retear group, and 17 were included in the ${\geqq}3$ cm retear group. At the end of the follow up period, all 109 patients showed a statistical significant improvement in the shoulder functional score. Conclusion: According to the follow up of the MRI scan, which was taken after the rotator cuff repair, the retear rate reached 34.9 %, and there were no significant differences on the age and the suture method. More rotator cuff retear occurred in male patients, and the initial tear size was positively correlated with the incidence rate of the rotator cuff retear. Also, the retear was more frequently observed at the medial side. That is because when the suture was performed, excessive tension was loaded on the medial side of the suture site.