• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.2
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• pp.53-67
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• 2008

In this study, seismic control performance of friction dampers installed in a reinforced concrete shear wall-moment frame system, of which main lateral force resisting system is a shear wall, is investigated. Three configurations of friction dampers are investigated. One is a diagonal brace type reinforcing the shear wall directly, another is a diagonal brace type reinforcing the moment frame without the shear wall, and the other one is a vertical boundary element type installed at both ends of the shear wall. In addition, various levels of the total friction force and its distribution methods are examined. Time history analysis considering material nonlinearity is conducted for seismic loads increased by the enhanced design code compared to the initial design loads, and energy dissipation, lateral loads and structural member damages are analyzed. As a result, the shear wall-reinforcing diagonal brace type with the total friction force of 30 % of the reference friction force gives the best performance on the whole, and the distribution methods of the friction force do not have remarkable difference in effects. Also, concentrated installation in adjacent four stories shows just a little compromised control performance compared to the entire story installation.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.137-149
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• 2009

Objectives : This study was designed to analyze whether General Coordinative Manipulation(GCM) Intervention could have effects on the balanced restoration of asymmetrical posture. Methods : Sixty eight(68) healthy volunteers(1st hypothesis: 46, 2nd hypothesis 22) participated in two GCM interventions, which have been performed 2 times a week for 3 weeks. The Global Postural System(GPS) Unit was used to measure the posture, and measurements were performed before and after the application of each intervention group. A paired t-test and wilcoxon test were used to determine the statistical significance. Results : The outcome of examining the hypothesis is as follows: 1. The 1st hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of upper extremity and the extension type of lower extremity, excluding self-care, shows the efficiency in treatment on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 3 of 4 body types. 2. The 2nd hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of lower extremity and the extension type of upper extremity, excluding self-care, shows the treatment in efficiency on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 2 of 3 body types. Conclusions : GCM intervention programs on the two hypothesis groups have an affect on the balanced restoration of the postural control system.

• Journal of Korean Association for Spatial Structures
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• v.8 no.1
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• pp.89-97
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• 2008

The object of this paper is to evaluate on behavior the experimentally of beam-to-column joints for modular steel frame with the hollow structural steel section to LEB C-shape. Beam-to-column joints carried out test on the joint shape bracket-type and welded-type to consideration which the joints for modular steel frame was capacity, deformation and failure mode. Test of results, the beam-column joints decided to the lateral buckling strength in LEB C-shape regardless of joint-shape and joint failure. The strength & stiffness for joints increase as the bracket-thickness. The results from theory of lateral buckling are compared to the experimental results. The ratio of experimental results to theory value is $0.83{\sim}0.95$ in the case of bracket-type and welded-type of $0.87{\sim}0.9$, indicating an accurate and safe estimation.

• Journal of Korean Foot and Ankle Society
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• v.16 no.3
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• pp.175-180
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• 2012

Purpose: To evaluate the radiological and clinical results after open reduction and internal fixation with calcaneal F plate and locking calcaneal plate using lateral extensile approach in the treatment of intra-articular calcaneal fracture Materials and Methods: This study included 34 cases of 33 patients followed up for at least 6 months postoperatively. F plate was applied in 18 cases (Group 1), locking plate was used in 16 cases (Group 2) and compared radiological and clinical results between two groups. Results: Radiollogically, the mean Bohler angle was improved from $5.5^{\circ}$ preoperatively to $20.1^{\circ}$ postoperatively and $18.8^{\circ}$ at the last follow up in group 1 and $8.6^{\circ}$ preoperatively, $21.4^{\circ}$ postoperatively and $20.3^{\circ}$ at last follow up in group 2. Bone union was observed in all cases and 4 cases of screw loosening were noted in Group 1 with extended fracture to anterior process. At the last follow up, both groups showed clinical results in American orthopedic foot and ankle society ankle hindfoot score, 76(77 in Sanders type II and 75 in type III) in group 1 and 72(73 in type II and 70 in type III) in group 2. Conclusion: F plate and locking plate showed firm fixation and satisfactory clinical results in the treatment of intra-articular calcaneal fracture. We suggest applying locking plate in cases with extended fracture to anterior process, considering screw loosenings in those who were treated with F plate fixation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.961-968
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• 2006

Curbs and L-type gutters installed at the edge of a road are very important structures to protect pedestrians from traffic accidents and to restraint slip of cars due to rain. However, existing construction method where great parts of the construction progress are done by human power has many problems in workability, quality and cost etc. In this paper, a new construction method for improvement in workability and quality for curbs and L-type gutters is developed. In order to investigate the structural safety and quality of curbs and gutters installed by the new method, tensile and lateral load tests are performed on curbs installed by existing and new methods and uniaxial compression tests are also performed on concrete samples of gutters constructed by existing and new methods. The test results show that the alignment of curbs and the strength of gutter concrete are very much improved by applying the new method. The tensile and lateral load capacities of the curbs installed by the new method are 10.7 and 2.5 times higher than those of curbs by existing method, respectively.

• Korean Journal of Radiology
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• v.23 no.8
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• pp.803-810
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• 2022

Objective: To investigate the clinical application of differential subsampling with Cartesian ordering (DISCO) contrast-enhanced (CE) magnetic resonance angiography for anterolateral thigh (ALT) flap transplantation, using operative findings as a reference. Materials and Methods: Thirty patients (21 males and nine females; mean age ± standard deviation, 45.5 ± 15.6 years) who were scheduled to undergo reconstruction with ALT flaps between June 2020 and June 2021 were included in the prospective study. Before ALT flap transplantation, patients were scanned using CE-DISCO imaging. All acquired DISCO images of the 60 lower limbs (both sides from each patient) were analyzed using maximum intensity projection and volume rendering methods. Two experienced radiologists were employed to examine the patterns of the lateral circumflex femoral artery (LCFA), its branches, and perforators and their skin termini, which were compared with the operative findings. Results: Using CE-DISCO, the patterns of the LCFA and its branches were clearly identified in all patients. Four different origins of the LCFA were found among the 60 blood vessels: type I (44/60, 73.3%), type II (6/60, 10.0%), type III (8/60, 13.3%), and type IV (2/60, 3.3%). Owing to a lack of perforators entering the skin, two patients did not undergo ALT flap transplantation. For the remaining 28 patients, the ALT flaps in 26 patients were successfully operated without flap reselection during the operation, while the remaining two patients underwent other surgical procedures due to the thin diameter of the perforator or injury of the perforator during the operation. The success rate of flap transplantation was 92.8% (26/28). All transplanted flaps exhibited good blood supply and achieved primary healing without infection or delayed healing. Conclusion: CE-DISCO imaging can be an effective method for preoperative perforator imaging before ALT flap transplantation.

• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.101-112
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• 1999

Structural walls have been mostly used for the design of reinforced concrete buildings in seismic areas because they play a role as an efficient bracing system and offer great potential for lateral load resistance and drift control. The lateral resistance system for the earthquake load should be designed to have enough ductility and stable hysteretic response in the critical regions where plastic deformation occurred beyond yielding. The behavior of the reinforced concrete element to experience large deformation in the critical areas by a major earthquake is affected by the performance of the confined core concrete. Thus, the confinement of concrete by suitable arrangements of transverse reinforcement results in a significant increase in both the strength and ductility of compressed concrete. This paper reports the experimental results of reinforced concrete structural walls for wall-type apartment structure under axial loads and cyclic reversal of lateral loads with different confinement of the boundary elements. The results show that confinement of the boundary element by open 'U'-bar and cross tie is effective. The shear strength capacity is not increased by the confinement but deformation capacity is improve.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.112-119
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• 2004

This paper develops a computer model of a cabover type large truck for estimating the effects of the mounted method of frame on handling performance. The computer model considers two mounted methods of frame; flange mounted and web mounted. Frame is modeled by finite elements using MSC/NASTRAN in order to consider the flexibility of frame. The reliability of the developed computer model is verified by comparing the actual vehicle test results with the simulation results. The actual vehicle test is performed in a double lane change course, and lateral acceleration, yaw rate, and roll angle are measured. To estimate the effects of the mounted method of frame on handling performance, simulations are performed with the flange mounted and web mounted frame. Simulation results show that the web mounted frame＇s variations of roll angle, lateral acceleration, and yaw rate are larger than the flange mounted frame＇s variations, especially in the high test velocity and the second part of the double lane course. Also, simulation results show that the web mounted frame＇s tendencies of roll angle, lateral acceleration, and yaw rate advance the flange mounted frame＇s tendencies, especially in the high test velocity and the second part of the double lane course.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.43-59
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• 2014

Many bridges are subject to lateral damage for their girders due to impact by over-height vehicles collision. In this study, the optimum configurations of carbon fiber reinforced polymers (CFRP) laminates were investigated to repair the laterally damaged prestressed concrete (PS) bridge girders. Experimental and analytical investigations were conducted to study the flexural behavior of 13 half-scale AASHTO type II PS girders under both static and fatigue loading. Lateral impact damage due to vehicle collision was simulated by sawing through the concrete of the bottom flange and slicing through one of the prestressing strands. The damaged concrete was repaired and CFRP systems (longitudinal soffit laminates and evenly spaced transverse U-wraps) were applied to restore the original flexural capacity and mitigate debonding of soffit CFRP longitudinal laminates. In addition to the static load tests for ten girders, three more girders were tested under fatigue loading cycles to investigate the behavior under simulated traffic conditions. Measurements of the applied load, the deflection at five different locations, strains along the cross-section height at mid-span, and multiple strains longitudinally along the bottom soffit were recorded. The study investigated and recommended the proper CFRP repair design in terms of the CFRP longitudinal layers and U-wrapping spacing to obtain flexural capacity improvement and desired failure modes for the repaired girders. Test results showed that with proper detailing, CFRP systems can be designed to restore the lost flexural capacity, sustain the fatigue load cycles, and maintain the desired failure mode.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.293-299
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• 2008

If a conventional type of Plastic Board Drain (PBD) is installed to the deep clay deposit, it is subjected to a high lateral earth pressure. a flow channel of PBD may be reduced by the collapse of cores and clogged by the intrusion of filter into the space between cores which are made by lateral pressure. It could decrease the ability of initial discharge capacity and the reliability of long term discharge capacity. A cylindrical plastic board drain (C-PBD) considered in this study consists of cylindrical core and several supports so that it can prevent the reduction of area of flow channel from the higher lateral earth pressure effectively. The discharge capacity of C-PBD was compared to that of a conventional PBD through performing experiments using the composite discharge capacity apparatus which can consider in-situ condition such as penetration of drains, ground settlement and discharge capacity. As a result, C-PBD showed much better performance than PBD in the ability of discharge. It was observed that the C-PBD was folded whereas the conventional PBD was folded after the experiment.