• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.71-78
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• 2012

The dynamic behavior of spatial structures is different depending on the aspect ration of arch structure, as the rise-span ratio or open-angle, and these spatial structures show differently the character of seismic response in accordance with stiffness and connection of the lower support structures that are directly influenced by earthquake. Therefore, in this paper, dynamic analysis is conducted for seismic response of single layer arch structures by the influence of column's stiffness and connection, to reflect the different vertical and horizontal vibration mode of single layer arch structures. The vertical response of single layer arch structures is more influence by lower columns and the influence of column's connection rotational stiffness is not large, except to the hinged connections.

• Journal of Korean Association for Spatial Structures
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• v.3 no.3 s.9
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• pp.95-103
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• 2003

Frame is one of the most commonly used structural systems for the resistance of applied loads. Many researchers have recently conducted their studies to investigate the effect of several parameters such as the connection flexibility, boundary condition of each support, beam-to-column stiffness ratio. These parameters play important roles on the characteristic behavior of frames. A simplified spring model is proposed to obtain the story drifts of frames with various beam-to-column connection stiffnesses in this research. A point bracing system with adequate spring stiffness is also suggested to establish the relationship between the applied load and the resisting translational spring stiffness within the limit state of story drift.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.340-342
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• 2001

This paper presents a utility interactive photovoltaic generation system with the angle of inclination and direction. This paper summarizes the results of these efforts by offering a snapshot of the configuration of photovoltaic in residential applications. The status of PV system components and inter-connection and safety equipment will be summarized. also, This System is able to alteration the angle of inclination and direction. Hence this paper discusses only points that might be useful for application.

• Journal of the Korean Institute of Rural Architecture
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• v.14 no.1
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• pp.21-28
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• 2012

Campus facilities were recently remodeled to provide the substantial learning rights of handicapped students in many campus to embody the dignity and value as man. So this study aims to identify the exterior connection facilities for handicapped students of S and D campuses. The summaries of this research are as follows. Installations of even crossing area(1.5mx1.5m) per 50m and even rest area(1.5mx1.5m) per 30m in walking or access ramp. Improving in accordance with exterior connection facility repairing master plan in S campus. Bringing down an angle degrees of the inclined walking or access ramp in D campus. Installation of exterior braille guide sign for blind students. All handicapped students must be guaranteed the same learning rights as normal men to remove obstacles as the upper mentioned imperfections in using exterior campus facilities.

• Steel and Composite Structures
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• v.16 no.2
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• pp.157-185
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• 2014

This paper examines the behaviour of two types of practical open beam-to-tubular column connection details subjected to combined moment, axial and/or shear loads. Detailed continuum finite element models are developed and validated against available experimental results, and extended to deal with flexural, axial and shear load interactions. A numerical investigation is then carried out on the behaviour of selected connections with different stiffness and strength characteristics under various load combination scenarios. The influence of applied levels of axial tensile or compressive loads on the bending stiffness and capacity is examined and discussed. Additionally, the interaction effects between shear forces and co-existing bending and axial loads are examined and shown to be comparatively insignificant in terms of stiffness and capacity in most cases. It is also shown that the range of connections considered in this paper can provide rotational ductility levels in excess of those required under typical design scenarios. Based on these findings, a simplified component-based representation is proposed and described, and its ability to represent the connection response under combined loading is verified using results from detailed numerical simulations.

• Structural Engineering and Mechanics
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• v.81 no.4
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• pp.493-502
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• 2022

Shear lag phenomenon has long been considered in numerous structural codes; however, the AISC provisions have now no longer proposed any unique equation to calculate the shear lag ratio in bolted connections for angles in general. It is noticeable that, however, codes used in this case are largely conservative and need to be amended. A parametric study consisting of 27 angle sections with equal legs and different with bolted connections was performed to investigate the effects of shear lag on the ultimate tensile capacity of angle members. The main parameters were: steel grade, connection length and eccentricity from the center of the plate, as well as the number of rows of bolts parallel to the applied force. The test results were compared with the predictions of the classical 1-x/l law proposed by Mons and Chesen to investigate its application to quantify the effect of shear lag. A parametric study was performed using valid FE models that cover a wide range of parameters. Finally, based on the numerical results, design considerations were proposed to quantify the effect of shear lag on the ultimate tensile capacity of the tensile members.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.1
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• pp.23-32
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• 2018

In this study, we conducted a shake table test to verify the seismic performance of the paneling system with steel truss composed of bolt connections. The control group was set to the traditional paneling system with steel truss connected by spot welding method. Test results showed that the bolted connection type paneling system has excellent deformation capacity without cracking or brittle fracture of the steel truss connection parts compared to the welding type paneling system. Furthermore, in the bolted connection type, slight damage occurred at the time of occurrence of the same story drift angle as compared with the existing method, it is considered that it has excellent seismic performance. In compliance with the performance-based design recommended for the current code (ASCE 41-13) on non-structural components, it is judged that in the case of the bolted connection type paneling system, it can be applied to all risk category structures without restriction. However, in the case of traditional paneling system with spot welding method, it is considered that it can be applied limitedly.

• Steel and Composite Structures
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• v.39 no.4
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• pp.383-399
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• 2021

In the study, three 1:3-scale unequal span steel-concrete composite substructures with top-seat angle and double web angle connection were designed and identified as specimens GTSDWA-0.6, GTSDWA-1.0, and GTSDWA-1.4. Pseudo-static tests and refined numerical model analysis were conducted to examine the anti-progressive collapse performance of a semi-rigid steel-concrete composite substructure. The results indicated that the failure modes of the three specimens revealed that the fracture occurred in the root of the long leg of the top/seat angle in tension at the connection. With increases in the span ratio of the left and right composite beams, the bearing capacities of the composite substructures decreased, and the corresponding displacement increased. With respect to GTSDWA-0.6 and GTSDWA-1.4, the resistance due to the short composite beam corresponded to 62% and 60%, respectively, and the total resistance provided by the short composite beam exceeded that of the long composite beam. With respect to GTSDWA-1.0, the resistance due to the left and right composite beams was similar. All three specimens underwent the flexure mechanism and flexure-axial mixed mechanism stages. They resisted the external load mainly via the flexure mechanism. Moreover, the addition of stiffeners on both sides of the top and seat angles is advantageous in terms of improving the collapse resistance and ductility of unequal span composite substructures.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.1
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• pp.32-44
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• 2023

Purpose: The purpose of this study was to investigate the effect of implant connection type on marginal bone loss (MBL) and to analyze the factors that affect MBL. This study focuses on single implants planted in the upper and lower first molar area. Materials and Methods: A total of 87 implants from 68 patients were tracked for a period over 5 years. There were 57 external connection type (EC) implants and 30 internal connection type (IC) implants in 38 males and 30 females. The MBL and EA were measured from intraoral radiograph images taken after 5 years at most. Results: Significant difference in MBL between EC and IC type was observed in patients without GBR or diabetes. Patients without GBR exhibited an MBL of -0.065 ± 0.859 mm in EC type and -0.627 ± 0.639 mm in IC type (P = 0.025). Using multiple regression analysis, a statistically significant negative correlation was observed between MBL and conditions including implant-abutment connection type (β = -0.303), diabetes (β = -0.113), emergence angle > 30° (β = -0.234), and age (β = -0.776). Conclusion: Within this results, IC type implants had less MBL than EC type, and implant prosthesis with emergence angle over 30° showed greater MBL. To minimize the MBL of the implant and ensure implant stability, careful consideration should be given to the EA of implant prosthesis and its connection type.

• Journal of Korean Physical Therapy Science
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• v.24 no.3
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• pp.12-17
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• 2017

Purpose: The purpose of this study was to investigate the effects of backrest angle on lower extremity muscle strength in adult. Method: This research results are based on 10 healthy adults. 10 degree difference in pelvic angle does not effect the cross-connection of the Hamstring muscles, and created 3 types of rest with 20 degree differences each at 95, 115, and 135 degree angles. Result: significantly difference in contractibility muscle strength in accordance to the 3 rake angle. Conclusion: After putting together all these results, since both the expansibility muscle strength and contractibility muscle strength of the knee showed to be effected as the backrest angle changed during isokinetic muscle strength assessment, further research should be conducted if similar research results as this study can be acquired at various angles.