• Journal of the Korean Academy of Clinical Electrophysiology
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• v.7 no.1
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• pp.35-42
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• 2009

Purpose : The purpose of this study was to investigate the effects of Swiss ball lumbar stabilization exercise on the strength and flexibility, balance for the subjects. 30 university students who aged an average $23.21{\pm}4.41$ years. Methods : The exercise program lasted for 4 weeks with a frequency of 3 times per week within 12 to RPE. The result was analyzed by case study were measured by sit-up for strength, and back muscle strength, and trunk flexion test and trunk extension lifting for flexibility, and also measured by balance test before and during, and after the Swiss ball exercise program. Statistical analysis was performed using SPSS/Win(15.0) version and t-test. Results : By the result of this study, we found that the number of performing sit-up strength was increased, and back muscle strength was increase, and trunk flexion test and trunk extension lifting was increased after the 4 weeks Swiss ball exercise program. Conclusion : These finding indicate that Swiss ball lumbar stabilization exercise using Swiss ball could be beneficial to the subjects. The effect of increasing strength and flexibility, balance was flexibility.

• Computers and Concrete
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• v.25 no.3
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• pp.273-282
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• 2020

A new seismic design methodology for precast concrete diaphragms has been developed and incorporated into the current American seismic design code. This design methodology recognizes that diaphragm inertial forces during earthquakes are highly influenced by higher dynamic vibration modes and incorporates the higher mode effect into the diaphragm seismic design acceleration determination using a first mode reduced method, which applies the response modification coefficient only to the first mode response but keeps the higher mode response unreduced. However the first mode reduced method does not consider effects of diaphragm flexibility, which plays an important role on the diaphragm seismic response especially for the precast concrete diaphragm. Therefore this paper investigated the effect of diaphragm flexibility on the diaphragm seismic design acceleration for precast concrete shear wall structures through parametric studies. Several design parameters were considered including number of stories, diaphragm geometries and stiffness. It was found that the diaphragm flexibility can change the structural dynamic properties and amplify the diaphragm acceleration during earthquakes. Design equations for mode contribution factors considering the diaphragm flexibility were first established through modal analyses to modify the first mode reduced method in the current code. The modified first mode reduced method has then been verified through nonlinear time history analyses.

• Structural Engineering and Mechanics
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• v.56 no.2
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• pp.169-188
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• 2015

There are two types of nonlinear analysis methods for building frameworks depending on the method of modeling the plastification of members including lumped plasticity and distributed plasticity. The lumped plasticity method assumes that plasticity is concentrated at a zero-length plastic hinge section at the ends of the elements. The distributed plasticity method discretizes the structural members into many line segments, and further subdivides the cross-section of each segment into a number of finite elements. When a reinforced concrete member experiences inelastic deformations, cracks tend to spread form the joint interface resulting in a curvature distribution. The program IDARC includes a spread plasticity formulation to capture the variation of the section flexibility, and combine them to determine the element stiffness matrix. In this formulation, the flexibility distribution in the structural elements is assumed to be the linear. The main objective of this study is to evaluate the accuracy of linear flexibility distribution assumed in the spread inelasticity model. For this purpose, nonlinear analysis of two reinforced concrete frames is carried out and the linear flexibility models used in the elements are compared with the real ones. It is shown that the linear flexibility distribution is incorrect assumption in cases of significant gravity load effects and can be lead to incorrect nonlinear responses in some situations.

• Earthquakes and Structures
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• v.15 no.5
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• pp.463-471
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• 2018

The virtual forces of the original local flexibility method are restricted to inducing stress on the local parts of a structure. To circumvent this restriction, we developed a pseudo local flexibility (PLFM) method that can successfully detect damage to hyperstatic beam structures using fewer modes. For this study, we further developed the PLFM so that it could detect damage in plate structures. We also devised the theoretical background for the PLFM with non-local virtual forces for plate structures, and both the lateral and rotary degree of freedom (DOF) measurements were considered separately. This study investigates the effects of the number of modes, the actual location that sustained damage, multiple damage locations, and noise in modal parameters for the damage detection results obtained from damaged numerical plates. The results revealed that the PLFM can be used for damage detection, localization, and quantification for plate structures, regardless of the use of the lateral DOF and/or rotary DOF.

• Structural Engineering and Mechanics
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• v.40 no.1
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• pp.121-148
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• 2011

Closed form solutions for equilibrium and flexibility matrices of the Mindlin-Reissner theory based eight-node rectangular plate bending element (MRP8) using Integrated Force Method (IFM) are presented in this paper. Though these closed form solutions of equilibrium and flexibility matrices are applicable to plate bending problems with square/rectangular boundaries, they reduce the computational time significantly and give more exact solutions. Presented closed form solutions are validated by solving large number of standard square/rectangular plate bending benchmark problems for deflections and moments and the results are compared with those of similar displacement-based eight-node quadrilateral plate bending elements available in the literature. The results are also compared with the exact solutions.

• Structural Engineering and Mechanics
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• v.8 no.3
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• pp.285-297
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• 1999

A method is presented to find the location and magnitude of damage in a structure using data from dynamic tests. The test data include a combination of natural frequency measurements, taken before and after the occurrence of damage, and response measurements taken after damage. An algorithm is developed to identify localized increases in the flexibility of the structural members. Increases in flexibility are attributed to damage. The algorithm uses the sensitivity of the flexibility matrix to changes in the natural frequencies of the structure to identify the damage. A set of under determined equations is solved using an objective function which is derived from measurements of the system moments. Damage ranging from 10 to 60% increase in the flexibility of a member was successfully identified in a 50 d.o.f. structure, using a small number of natural frequency and velocity measurements.

• 대한근관절건강학회:학술대회논문집
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• 2001.04a
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• pp.179-190
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• 2001

The purpose of this study was to explore the effects of GEAP on pain, joint function, activities of daily living(ADL) and fatigue in chronic arthritis patients. The GEAP was held twice a week for 6 weeks for chronic arthritis patients at one university hospital in Seoul, Korea. Thirty four subjects completed the program, who were recruited at four times from September, 1999 to September, 2000. The effect of GEAP were evaluated as follows: Pain severity and number of painful joints ADL, fatigue were measured before and after the GEAP. In order to examine the joint flexibility and strengthening, the followings were measured: the extent of the upward arm reach in both sides(flexibility of shoulder), the ability to touch fingertips of the both hands in back pat and rub(flexibility of arm), the degree of range of motion (ROM) of both ankles in their dorsiflexion(flexibility of ankle) and plantarflexion with standing with toe(strengthening of ankle), and the degree of knee extension, and the grip strength. Paired t-test and Wilcoxon signed rank test were used for data analysis and the significance of the differences in the variables was examined to compare the data obtained before and after the GEAP. After the GEAP, followings were found: 1. Pain severity and number of painful joints was significantly decreased. 2. The flexibility of both shoulders and arms, knee, both ankle were significantly improved. 3. The strengthening of both arms was significantly improved, but the strengthening of ankle was not changed. 4. ADL was significantly increased. 5. Fatigue was significantly decreased. In conclusion, GEAP used in this study was clearly proved to be an effective exercise program to reduce pain and fatigue, to enhance joint function and ADL in people with chronic arthritis. It is suggested that the GEAP should be recommended as one of the useful and appropriate nursing interventions for chronic arthritis patients.

• The Journal of Korean Physical Therapy
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• v.13 no.1
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• pp.73-82
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• 2001

In order to study the effect of the isometric exercises on the flexibility. the strength and the waist and hip circumferences, 10 female university students who aged 22.10 ${\pm}$ 1.10 years were measured by sit-up for strength, and trunk flexion test and trunk lifting for flexibility, and also measured by waist and hip circumferences before and during, and after the Swiss ball exercise program. Statistical analysis was performed using SPSS/PC WIN 7.0 version. and one-way repeated ANOVA Test, The results of the test were as shown; We found that the number of performing sit-up was increased. and the trunk flexion test and trunk lifting was increased, and the waist and hip circumferences were increased after the 6 weeks Swiss ball exercise program. These findings indicate that Isometric exercise using Swiss ball could be beneficial to the low back pain patients due to the effect of increasing strength and flexibility of the patients.

• KIEAE Journal
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• v.12 no.1
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• pp.21-27
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• 2012

This study aims at finding the trend changes of spatial configuration in housing units of Korean apartments in the 2000s. Among the housing units in the apartments built by large construction companies, we have selected ones with small and regular sizes, $59m^2$ and $84m^2$ respectively, and investigated the number of bays, the location of wet zone and the spatial flexibility in the housing units selected for analysis. In conclusion, the number of bays in the housing unit has gradually increased, after allowing for the structural change of the balcony in the legal. It is estimated that the trend has came from the intent to increase the numbers of the externally exposed surfaces of the balcony, ensure a good view, lighting, ventilation and spatial flexibility. The location of wet zone, water-needed space such as a bathroom or a kitchen, has changed in the direction to facilitate the expansion and modification of space. Variable range of space has gradually expanded by using the balcony and wet zone as much as possible. In order to configure more effectively spaces in housing environments, the future study should be implemented to develop tools for realizing sustainable housing environment at the levels of not only the housing unit. but also the entire building, housing site, and city.

• Journal of muscle and joint health
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• v.15 no.1
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• pp.62-72
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• 2008

Purpose: There has been a need to integrating the self-help program for arthritis with the Tai Chi for arthritis(SHTCA). The purpose of this study was to develop and to examine the effect of SHTCA for arthritis applying the nine movement Tai Chi. Method: This study was designed the pre-post test, quasi-experimental design. A total 47 participants were recruited in W-city in Korea, an experimental group(26) and a control group(21) at pre-test, but after the eight weeks the composition of the groups were changed to 22 experimental group and 15 control group. The experimental group participated in the SHTCA once a week for eight weeks. SHTCA program consisted of understanding of the arthritis, contracting of the promise, exercise for muscle strength and joint flexibility and the nine movements of Tai Chi exercise. The measures used to examine the effect of the SHTCA were shoulder flexibility, back flexibility, grasping power, balance, abdominal obesity rates, perception of health status, and EQ-5D standardized five dimensions, mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Results: At The completion of the eight weeks of SHTCA applying the nine movement Tai Chi, the experimental group reported a significance in a number of variables compared to those of the control group: the right shoulder flexibility(p=.018), left shoulder flexibility(p=.031), right grasping power(p=.014), left grasping power(p=.024), the perception of health status(p=.005) and abdominal obesity rates(p=.027). Conclusion: This SHTCA applying the nine movement Tai Chi would be helpful on right shoulder flexibility, left shoulder flexibility, right grasping power, left grasping power, abdominal obesity rates and the perception of health status for arthritis patients.