• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.445-454
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• 2020

Structural damage identification (SDI) is a crucial step in structural health monitoring. However, some of the existing SDI methods cannot provide enough identification accuracy and efficiency in practice. A novel whale optimization algorithm (WOA) based method is proposed for SDI by weighting modal data and flexibility assurance criterion in this study. At first, the SDI problem is mathematically converted into a constrained optimization problem. Unlike traditional objective function defined using frequencies and mode shapes, a new objective function on the SDI problem is formulated by weighting both modal data and flexibility assurance criterion. Then, the WOA method, due to its good performance of fast convergence and global searching ability, is adopted to provide an accurate solution to the SDI problem, different predator mechanisms are formulated and their probability thresholds are selected. Finally, the performance of the proposed method is assessed by numerical simulations on a simply-supported beam and a 31-bar truss structures. For the given multiple structural damage conditions under environmental noises, the WOA-based SDI method can effectively locate structural damages and accurately estimate severities of damages. Compared with other optimization methods, such as particle swarm optimization and dragonfly algorithm, the proposed WOA-based method outperforms in accuracy and efficiency, which can provide a more effective and potential tool for the SDI problem.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.6
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• pp.1439-1450
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• 1995

Bellows is a familiar component in piping systems as it provides a relatively simple means of absorbing thermal expansion and providing system flexibility. In routine piping flexibility analysis by finite element methods, bellows is usually considered to be straight pipe runs modified by an appropriate flexibility factor; maximum stresses are evaluated using a corresponding stress concentration factor. The aim of this study is to develop a bellows finite element, which similarly includes more complex shell type deformation patterns. This element also does not require flexibility or stress factors, but evaluates more detailed deformation and stress patterns. The proposed bellows element is a 3-D, 2-noded line element, with three degrees of freedom per node and no bending. It is formulated by including additional 'internal' degrees of freedom to account for the deformation of the bellows corrugation; specifically a quarter toroidal section of the bellows, loaded by axial force, is considered and the shell type deformation of this is include by way of an approximating trigonometric series. The stiffness of each half bellows section may be found by minimising the potential energy of the section for a chosen deformation shape function. An experiment on the flexibility is performed to verify the reliability for bellows finite element.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.4
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• pp.369-379
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• 2011

Purpose : The purpose of this study is to compare the initial effect of nerve mobilization (NM), static stretching (SS), and contract-relax (CR) techniques to find the best method in improving hamstring flexibility and gait function in patients with hemiplegia. Methods : Eleven patients with hemiplegia were included in this study. Passive knee extension (PKE) range of motion and the sit and reach (SR) test were used to measure hamstring flexibility, while timed up and go (TUG) and the 10m walking (10MW) test were used to measure the subject's gait. Measurements on each test were assessed prior to the experiment, immediately following the experiment, and 30 minutes after the experiment. Analysis of the results utilized a repeated measures analysis of variance to examine hamstring flexibility and the difference in walking ability. Results : The results suggest significant increases in NM, SS, and CR techniques as they relate to hamstring flexibility (p<.05) following (both immediate and 30 minutes post experiment) PKE range of motion and the SR test, but post-hoc showed no significant difference between the three techniques (p>.05). Additionally, the results suggest significant increases in NM, SS, and CR techniques as they relate to gait function (p<.05) following the TUG test, but found no significant difference in the 10MW test (p>.05). Post-hoc analysis between the three techniques suggests that only the NM technique significantly changed gait function. The time of TUG and 10MW test showed no significant difference between the three techniques before an experiment, just after an experiment, and 30 minutes following the experiment according to the measurement points in time (p>.05). Conclusion : This study suggests NM, SS, and CR techniques immediately improve hamstring length and flexibility while improving gait function in patients with hemiplegia.

• 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.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.11a
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• pp.191-192
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• 2007

This design plan aims at the designing of the pharmacy counter as the space in which the two inter-related elements of the pharmacy, for example, the pharmacist and the customers, selling medicines and transmitting health informations, etc. keep in contact with each other. To create an ambience of intercommunication for health care and relaxation, it must be set up the basic concepts like Functionality, Flexibility, Transparence and Material-Change. As the design solutions : - first of all the long counter must be divided into the independent places with character and function. - in accordance with the basic concepts functionality and flexibility each small counter must represent a one's own form language that is determined according to a given function and also open and flexible to the change of the situation. - the various kinds of display module are introduced to bring out the functionality and the aestheticity simultaneously. - to make a contrasting image to each other various materials are arranged on and around the counters.

• Structural Engineering and Mechanics
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• v.70 no.6
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• pp.649-659
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• 2019

Vibration-based structural damage detection through optimization algorithms and minimization of objective function has recently become an interesting research topic. Application of various objective functions as well as optimization algorithms may affect damage diagnosis quality. This paper proposes a new damage identification method using Moth-Flame Optimization (MFO). MFO is a nature-inspired algorithm based on moth's ability to navigate in dark. Objective function consists of a term with modal assurance criterion flexibility and natural frequency. To show the performance of the said method, two numerical examples including truss and shear frame have been studied. Furthermore, Los Alamos National Laboratory test structure was used for validation purposes. Finite element model for both experimental and numerical examples was created by MATLAB software to extract modal properties of the structure. Mode shapes and natural frequencies were contaminated with noise in above mentioned numerical examples. In the meantime, one of the classical optimization algorithms called particle swarm optimization was compared with MFO. In short, results obtained from numerical and experimental examples showed that the presented method is efficient in damage identification.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.289-300
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• 2013

The aims of this study are to investigate the differences of the preschoolers' executive function and verbal ability according to their age, and to identify whether the preschoolers' executive function is related to their verbal ability. The participants in this study are 151 children, ages 3-and 5-years old from five child-care centers located in a middle-income region of Seoul. Statistical methods used for the data analysis are the frequencies, means, standard deviations, an independent t-test, and Pearson correlation. The major findings are as follows. First, an age difference is found for children's executive function. The 5-year-olds are more likely to succeed on tasks of executive function than the 3-year-olds. Also, age difference is found for children's verbal ability. The 5-year-olds perform better on tests of verbal ability than the 3-year-olds. Last, the 3-year-olds' and 5-year-olds' executive function is related to their verbal ability. Inhibition and cognitive flexibility are significantly correlated with verbal ability. These results suggest that preschoolers' executive function and verbal ability develop during preschool age. These results also suggest that preschoolers' executive function is related to their verbal ability.

• Journal of muscle and joint health
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• v.18 no.1
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• pp.83-92
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• 2011

Purpose: The purpose of this study was to identify the changes of physical function, perceptual and cognitive function, emotional function, and functional independence in the institutionalized aged according to functional group activity program (self help Tai Chi exercise plus functional task). Methods: Study subjects were 20 institutionalized aged from June to October in 2010. The subjects received functional group activity program two times a week for 15 weeks. Physical function (grip strength, coordination, lower extremity strength, balance, gait, trunk flexibility), perceptual and cognitive function, emotional function(depression, social skill), and functional independence were measured before and after the program. Results: The subjects showed significantly increased physical function (coordination, lower extremity strength, gait, trunk flexibility), perceptual and cognitive function, emotional function (depression, social skill), and functional independence. The functional group activity program may be an effective strategy for institutionalized elders to enhance their functions. Conclusion: The functional group activity program may be effective on elderly institutions which have limitation in human, material, environmental resources.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.24 no.1
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• pp.23-29
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• 2018

Background: This study aimed to the effects of hip mobilization on pain, trunk flexibility, function for chronic low back pain patients. Methods: Patients were randomly assigned to control group (n=15) and experimental group (n=15). Both groups received conventional physical therapy, three times a week for four weeks. Experimental group was performed additional hip mobilization, three times a week for four weeks. All measurement of each subject were measured at pre-intervention and post-intervention (after 4 weeks). Results: Assessed items included the visual analog scale score (VAS), Korean version of the Oswestry disability Index (KODI) a significant reduction was observed post intervention compared to pre-intervention values in both group (p<.01). Trunk flexibility was significant increased post intervention compared to pre-intervention values in both group (p<.01). There were significant difference between two groups in VAS (p<.01), trunk flexibility (p<.05) and except KODI. Conclusions: Our results indicate that conventional physical therapy with the hip mobilization may be useful for improving chronic low back pain patient.

• Journal of Korean Academy of Nursing
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• v.39 no.4
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• pp.584-593
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• 2009

Purpose: The purpose of this study was to investigate the effect of stretching, muscle strengthening, and walking exercise on the cardiopulmonary function and health-related quality of life in hemodialysis patients. Methods: Twenty-one patients in the intervention and the control group participated in the exercise respectively on maintenance hemodialysis at four university hospitals. The exercise was composed of 20 to 60 min per session, 3 sessions a week for 12 weeks. The effect of exercise was assessed by cardiopulmonary function (peak oxygen uptake, peak ventilation, peak respiration rate, maximal heart rate, and exercise duration) using a cycle ergometer. Grip strength was measured by dynamometer, and flexibility was measured by sit and reach measuring instrument. Health-related quality of life was measured using Medical Outcomes Study Short Form-36. Results: Peak oxygen uptake, peak ventilation, peak respiration rate, exercise duration, grip strength, flexibility, and physical component scale were significantly improved in the intervention group after 12 week's exercise compared to the control group. Conclusion: These findings indicate the exercise can improve cardiopulmonary function, grip strength, flexibility, and physical component scale of health-related quality of life in hemodialysis patients.