• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.205-213
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• 2017

The WUF-W moment connection is a pre-qualified connection that can be used for special moment frames specified in current seismic design specifications. Since the stress distribution near the connection varies according to access hole configuration, the cyclic performance of WUF-W connections is strongly affected by the access hole configurations. To evaluate the connection performance according to various access hole configurations, it is expensive to conduct experiments with many connection specimens. Instead, finite element analyses (FEA) can be performed. Throughout the FEA, stress and strain distribution in the connection can be monitored at each loading step. The purpose of this study is to construct nonlinear 3-dimensional FE models for accurately predicting the cyclic behavior of WUF-W connections. For predicting connection fracture using FEA, an appropriate response index detecting the incidence of connection rupture is proposed.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.651-658
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• 2010

Sixteen concrete mixes reinforced with hybrid steel-polybinyl alcohol (PVA) fibers and a control concrete mix with no fiber were tested in order to examine the effect of the micro and macro fibers on the slump and different mechanical properties of concrete. Main variables investigated were length and volume fraction of steel and PVA fibers. The measured mechanical properties of hybrid fiber reinforced concrete were analyzed using the fiber reinforcing index and compared with those recorded from monolithic steel or PVA fiber reinforced concrete. The initial slump of hybrid fiber reinforced concrete decreased with the increase of the aspect ratio and the volume fraction of fibers. In addition, splitting tensile strength, modui of rupture and elasticity, and flexural toughness index of concrete increased with the increase of the fiber reinforcement index. Modulus of rupture and flexural toughness index of hybrid fiber reinforced concrete were higher than those of monolithic fiber reinforced concrete, though the total volume fraction of hybrid fibers was lower than that of monolithic fiber. For enhancing the flexural toughness index of hybrid fiber reinforced concrete, using the steel fiber of 60 mm length was more effective than using the steel fibers combined with 60 mm and 30 mm lengths.

• Journal of Korean Foot and Ankle Society
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• v.27 no.1
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• pp.12-16
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• 2023

Purpose: Postoperative exercise for acute Achilles tendon rupture is important for a patient's return to daily life and sports. On the other hand, the protocol requires considerable effort to educate patients and continuous checking. This study evaluated the outcome of a new simple and delayed rehabilitation protocol after Achilles tendon rupture repair. Materials and Methods: From July 2014 to November 2020, one hundred eighty-three patients were operated on by one surgeon. The exercise protocol was classified into two methods. One group (immediate protocol, control group) started immediate full weight bearing with a 20° plantar flexion range of motion from two days postoperatively. Ankle dorsiflexion was restricted to 0°. The other group (delayed protocol, case group) started full weight bearing with a controlled ankle motion boot from two weeks postoperatively. No range of motion exercise was allowed until six weeks postoperatively. Age, sex, body mass index, ankle range of motion, muscle power, time to return to previous physical activity, functional score, and complication rate were evaluated. The results of the two groups were compared using a Mann-Whitney test. Statistical significance was set as p<0.05. Results: The range of motion, double heel rising, and one-leg standing were achieved faster in the control group (p<0.05). However, single-heel rising, repeated single-heel rising, return to previous activity (work, run, and sport), and functional scores showed no statistical difference (p>0.05). Conclusion: Simple and delayed postoperative rehabilitation of acute Achilles tendon rupture without active range of motion exercises showed satisfactory functional results and a low complication rate.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.11 no.2
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• pp.35-44
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• 2016

Objective : The objective of this study is to report the effect of Korean Rehabilitation Treatment with CHUNA Manual Therapy and Exercise Therapy on Postoperative Anterior Cruciate Ligament rupture of knee. Methods : Two patients were treated by Korean Rehabilitation with CHUNA Manual Therapy and Exercise Therapy at knee. We evaluated the effectiveness by Visual Analog Scale(VAS) and Western Ontario and McMaster Universities Arthritis Index(WOMAC) and Range of motion(ROM) Results : Both patients had significant improvement on Knee ROM, VAS score and WOMAC index. Also physical examination of Knee was improved. Conclusions : This study showed that Korean Rehabilitation Treatment with CHUNA Manual Therapy and Exercise Therapy has meaningful effect on Postoperative of anterior cruciate ligament rupture of knee. But there is a limit on this study due to sufficient number of cases. Further studies will be needed.

• Steel and Composite Structures
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• v.35 no.3
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• pp.353-370
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• 2020

This paper describes a new type of replaceable fuse for moment resisting frames. Column-tree connections with beam splice connections are frequently preferred in the moment resisting frames since they eliminate field welding and provide good quality. In the column-tree connections, a part of the beam is welded to the column in the shop and the rest of the beam is bolted with the splice connection in the field. In this study, a replaceable reduced beam section (R-RBS) connection is proposed in order to eliminate welding process and facilitate assembly at the site. In the proposed R-RBS connection, one end is connected by a beam splice connection to the beam and the other end is connected by a bolted end-plate connection to the column. More importantly is that the proposed R-RBS connection allows the replacement of the damaged R-RBS easily right after an earthquake. Pursuant to this goal, experimental and numerical studies have been undertaken to investigate the performance of the R-RBS connection. An experimental study on the RBS connection was used to substantiate the numerical model using ABAQUS, a commercially available finite element software. Additionally, five different finite element models were developed to conduct a parametric study. The results of the analysis were compared in terms of the moment and energy absorption capacities, PEEQ, rupture and tri-axiality indexes. The design process as well as the optimum dimensions of the R-RBS connections are presented. It was also demonstrated that the proposed R-RBS connection satisfies AISC criteria based on the nonlinear finite element analysis results.

• Geomechanics and Engineering
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• v.29 no.6
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• pp.599-614
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• 2022

In this study, the reliability analysis of internal and external stabilities of Reinforced Soil Walls (RSWs) under static and seismic loads are investigated so that it can help the geotechnical engineers to perform the design more realistically. The effect of various variables such as angle of internal soil friction, soil specific gravity, tensile strength of the reinforcements, base friction, surcharge load and finally horizontal earthquake acceleration are examined assuming the variables uncertainties. Also, the correlation coefficient impact between variables, sensitivity analysis, mean change, coefficient of variation and type of probability distribution function were evaluated. In this research, external stability (sliding, overturning and bearing capacity) and internal stability (tensile rupture and pull out) in both static and seismic conditions were investigated. Results of this study indicated sliding as the predominant failure mode in the external stability and reinforcing rupture in the internal stability. First-Order Reliability Method (FORM) are applied to estimate the reliability index (or failure probability) and results are validated using the Monte Carlo Simulation (MCS) method. The results showed among all variables, the internal friction angle and horizontal earthquake acceleration have dominant impact on the both reinforced soil wall internal and external stabilities limit states. Also, the type of probability distribution function affects the reliability index significantly and coefficient of variation of internal friction angle has the greatest influence in the static and seismic limits states compared to the other variables.

• The Journal of Internal Korean Medicine
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• v.44 no.5
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• pp.1050-1061
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• 2023

This study reported the case of a patient with quadriparesis due to cerebral aneurysm rupture, subarachnoid hemorrhage, and intraventricular hemorrhage (IVH) treated with Korean medicine. The patient was treated with acupuncture, herbal medicine (mainly Tonggyuhwalhyeol-tang-gagam), Western medicine, moxibustion, cupping, and rehabilitative therapy for 75 days, and improved after administration. After treatment, the Manual Muscle Test grade improved from 4/4-/3+/3 to 4+/4+/4+/4+, the Korean version of the modified Barthel Index score improved from 9 to 100, the National Institute of Health's Stroke Scale score improved from 2 to 0, the Global Deterioration Scale score improved from 3 to 2, and the Korean version of the Mini-Mental State Examination score improved from 22 to 30. During administration, the patient did not show seizures, shock, or loss of consciousness, and the vital signs were stable in the normal range. We followed up the brain computed tomography findings for 2 times and found that there was no definite evidence of intracranial hemorrhage or IVH or re-rupture or rebleeding after Korean medicine treatment. This study suggests that Korean medicine treatment with blood-invigorating and stasis-removing herbs could be a safe and effective intervention option for improving quadriparesis due to cerebral aneurysm rupture and subarachnoid hemorrhage.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.109-114
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• 2002

Propose : The purpose of this retrospective study was to test the posterior cruciate ligament (PCL index) for diagnosis of a tear of the anterior cruciate ligament (ACL) by means of MR imaging. Materials and Methods : From Mar. 1997 to Feb. 2001, concomitant magnetic resonance imaging (MRI) and knee joint arthroscopy were performed in 56 patients of either pain or instability of the knee. The shortest distance between the femoral and tibial attachment of PCL (X) and the distance from that line to the tip of the arc marked by the PCL (Y) on the sagittal plane images were measured. The quotient of these two parameters (Y/X) defined the PCL index. Results : Using MRI diagnosis, there were 35 patients diagnosed with ACL rupture and 21 patients were ruled out of ACL injury. Using arthroscopy, 32 of the 35 patients diagnosed by MRI showed ACL rupture, and 20 of the 21 patients were ruled out of ACL injury. The mean PCL index was 0.40 in the 33 patients diagnosed with ACL rupture through arthroscopy. The mean PCL index was 0.23 in 23 patients with an uninjured ACL through arthroscopy. In 33 patients with ruptured ACL, this value exceeds 0.31. The index value was 0.31 in 3 patients with uninjured ACL. The value of the index was not above 0.31 with an uninjured ACL. PCL index on MRI had a sensitivity of $91\%$ and a specificity of $94\%$ for determining the status of the anterior cruciate ligament. Conclusion : Injury to the ACL changes the PCL index markedly. In diagnostically unreliable MR images, amelioration of the PCL index could help in the diagnosis of ACL injury.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.200-207
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• 2003

The seismic behaviors of steel moment connections are investigated based on the numerical analysis of the connections with US and Japanese typical details. The rupture index, representing the fracture potential, is used to evaluate the ductility of the connections at the critical location. The results show that the presence of a slab increases the beam strength, imposes constraint near the beam top flange, and consequently, induces concentrated deformation near the beam access hall, which reduces the ductility of the connection. The total deformation capacity of the connection depends not only on a beam but also on a column and panel zone.

• Agricultural and Biosystems Engineering
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• v.2 no.2
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• pp.59-62
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• 2001

The starch content of apples, which is related to the maturity and ripeness, was quantified by using a computer vision system. The stained area was measured by image analysis when an apple slice was stained with KI/I$_2$ solution. The ratio of stained area of the apple slice to its whole area, so called the starch index, was defined as an indicator of the starch content. When Tsugaru apples were manually sorted into immature, turing and mature groups, their starch indices were 0.374, 0.312 and 0.129, respectively. The starch index had relationships to various physicochemical properties of Tsugaru apples. At the statistically significant level of 0.1%, it was correlated with the pH value, bio-yield force, rupture force and color of intact and skin-removed apples. At the 1% significant level, it had the correlation with the density and moisture content.