• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.63-71
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• 2018

Strands with ultimate strength of 2,400 MPa was developed and applied in the KCI Code and the KS standard. A high-strength prestressed strand to be applied to a structure, a suitable anchorage system should be used together. Recently, a post tension anchorage for 2,400 MPa strands was developed. but there is not much research on performance evaluation. Therefore, in this study, structural analysis of local zone with 9 strands, 15 strands, and 19 strands anchorage were investigated respectively, which are most widely used for post tensioning anchorages with 2,400 MPa strands, according to PTI anchorage zone design method, and Load transfer performance from ETAG013 and/or KCI-PS101 was evaluated. Furthermore, the adequacy of the test was also analyzed by nonlinear numerical analysis. As results, the anchorages with 2,400 MPa strands satisfied the structural performance of the local area and satisfied the load transfer performance condition.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.266-274
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• 2002

A typical case where the effects of prying in the base angle type anchorage system with expansion bolt. This connection consists of an angle which is attathed to an equipment cabinet and bolted to a concrete slab via an expantion bolt. A seismic analysis of the cabinet may indicate a vertical load, P, transferred to the vertical leg of the angle due to overturning of the cabinet. Due to the eccentricity, b(e), and the continuous beam action in the base member, the load resisted by the bolt will be amplified by a factor λ. Thus, in this study, experimental evaluation of the anchorage system is executed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.167-175
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• 2018

Load transfer experiments have been carried out to evaluate the performance of the anchorage and it has been stated that the specimens were manufactured and tested according to ETAG 013. On the other hand, the amount of spiral reinforcement and auxiliary reinforcement exceeded the amount specified in ETAG 013. In this study, the load transfer test method and the criteria specified in ETAG 013 were considered and the PT anchorage system was applied to manufacture specimens with high strength concrete and a high tensile prestressing strand. A load transfer test according to ETAG 013 was performed to evaluate the performance of the circular anchorage. As a result, it was confirmed that ETAG 013 is a very strict specification that does not satisfy the performance of an anchorage unless the specimens of an appropriate size and spiral reinforcement are used. To assess the stability of the specimens, increasing the size of the specimen by 15%, rather than increasing the amount of auxiliary reinforcement, is considered to be the correct method in accordance with ETAG 013.

• The korean journal of orthodontics
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• v.44 no.2
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• pp.88-95
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• 2014

Objective: The purpose of this study was to compare the treatment duration and dentoskeletal changes between two different anchorage systems used to treat maxillary dentoalveolar protrusion and to examine the effectiveness of en-masse retraction using two miniscrews placed in the midpalatal suture. Methods: Fifty-seven patients (9 men, 48 women), who had undergone level anchorage system treatment at Aichi-Gakuin University Dental Hospital (Nagoya, Japan) were divided into two groups according to the method of maxillary posterior anchorage reinforcement: midpalatal miniscrews (25 patients, mean age 22 years) and conventional anchorage (32 patients, mean age 19 years). The en-masse retraction period, overall treatment duration, pre-treatment effective ANB angle, and change in the effective ANB angle were compared with an independent-samples t -test. Results: Compared to the headgear group, the duration of en-masse retraction was longer by approximately 4 months in the miniscrew group (p < 0.001). However, we found no significant difference in the total treatment duration between the groups. Moreover, a greater change in the effective ANB angle was observed in patients treated with miniscrews than in those treated with the conventional method (p < 0.05). Conclusions: The level anchorage system treatment using miniscrews placed in the midpalatal area will allow orthodontists more time to control the anterior teeth during en-masse retraction, without increasing the total treatment duration. Furthermore, it achieves better dentoskeletal control than does the conventional anchorage method, thereby improving the quality of the treatment results.

• Journal of the Korean Geotechnical Society
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• v.37 no.2
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• pp.33-48
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• 2021

The rock anchorage of a suspension bridge is an outstanding anchorage type from environmental and economical perspective, although it should be applied when the bearing foundation is fresh enough to resist large cable loads. In practice, geotechnical engineers have encountered difficulties in designing the anchorage structure due to the fact that the physical behaviors of rocks against cable loads have not yet been fully proved and its design method was not established yet. In this study, model tests and numerical studies were performed to evaluate the behavior of the rock anchorage system planned under hard rock layers in domestic islands, and results suggest that the shape of asymmetric rock wedges can resist the tension loads with self weight and shear resistance. Additionally, real scale trial tests were carried out to verify the accuracy of an inclined drilling penetrating hard rock layers to install tendon to the bearing plate.

• Smart Structures and Systems
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• v.22 no.1
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• pp.57-70
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• 2018

For the long-term structural health monitoring of civil structures, the effect of ambient temperature variation has been regarded as one of the critical issues. In this study, a principal component analysis (PCA)-based algorithm is proposed to filter out temperature effects on electromechanical impedance (EMI) monitoring of prestressed tendon anchorages. Firstly, the EMI monitoring via a piezoelectric interface device is described for prestress-loss detection in the tendon anchorage system. Secondly, the PCA-based temperature filtering algorithm tailored to the EMI monitoring of the prestressed tendon anchorage is outlined. The proposed algorithm utilizes the damage-sensitive features obtained from sub-ranges of the EMI data to establish the PCA-based filter model. Finally, the feasibility of the PCA-based algorithm is experimentally evaluated by distinguishing temperature changes from prestress-loss events in a prestressed concrete girder. The accuracy of the prestress-loss detection results is discussed with respect to the EMI features before and after the temperature filtering.

• 대한치과보철학회:학술대회논문집
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• 2001.11a
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• pp.72-72
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• 2001

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.65-70
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• 2007

Until a recent date Wan-do Port has made efforts to advance its marine policy toward the base of marine distribution industry. Therefore the administration of Wan-do port has carried out many projects on improvements of harbour system very actively. The improvement of ship traffic system would be one of them. This research examined the general view of present situations of marine traffic system in Wan-do waters area and suggested improvements in ship route and anchorage.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.49-54
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• 2014

Development in vehicle industry could increase interest in children's safety recently. However the research of children safety is not being conducted as many as that of adult's. Especially the basic study for the vehicle crash on-board children was not much. This study focused on the effect of seatbelt anchorage points to evaluate children's safety in frontal crash. The current regulation of the seatbelt anchorage points is suitable for ranged from female 5% to male 95%. The assessment of children's safety at buckle up of no used CRS(child restraint system) was performed using frontal sled tests. The frontal crash pulse in sled tests was designed to the average of about 30 KNCAP frontal crash pulses. To reduce number of experiments, DOE is used. The Q6 child dummy and standard seat in UN R 129 were used. According to the analysis of test results, children's safety has been influenced by the points of seatbelt anchorage.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.464-474
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• 2009

To distalize the maxillary molars, the traditional techniques such as extra-oral traction, Wilson distalizing arches, removable spring appliances and Schwarz plate-type appliances have been used. But, these need considerable patient cooperation. For minimal patient compliance, many practitioners use the pendulum appliances. Several clinical studies demonstrated pendulum is effective molar distalization appliance in the growing patient(using the premolars and the palate as anchorage). But unfortunately, maxillary anterior teeth also shift mesially as the molar moves distally. As a result anchorage loss is occurred. To overcome these disadvantages, we used bone-supported pendulum, combined the conventional pendulum with Skeletal Anchorage System(SAS). The miniscrew was implanted in the anterior paramedian region of the median palatal suture, which has comparatively sufficient bone thickness and is low risk to damage on the dental follicles. We report three cases, using bone-supported pendulum for the maxillary molar distalization in children. After treatment, we find out anchorage stability, minimal unfavorable anterior tooth movement and sufficient molar distalization.