• Smart Structures and Systems
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• v.16 no.1
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• pp.223-242
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• 2015

Wireless sensor networks (WSNs) have emerged as a novel solution to many of the challenges of structural health monitoring (SHM) in civil engineering structures. While research projects using WSNs are ongoing worldwide, implementations of WSNs on full-scale structures are limited. In this study, a WSN is deployed on a full-scale 17.3m-long, 11-bay highway sign support structure to investigate the ability to use vibration response data to detect damage induced in the structure. A multi-level damage detection strategy is employed for this structure: the Angle-between-String-and-Horizon (ASH) flexibility-based algorithm as the Level I and the Axial Strain (AS) flexibility-based algorithm as the Level II. For the proposed multi-level damage detection strategy, a coarse resolution Level I damage detection will be conducted first to detect the damaged region(s). Subsequently, a fine resolution Level II damage detection will be conducted in the damaged region(s) to locate the damaged element(s). Several damage cases are created on the full-scale highway sign support structure to validate the multi-level detection strategy. The multi-level damage detection strategy is shown to be successful in detecting damage in the structure in these cases.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2396-2398
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• 1998

The Distribution Automation System(DAS) Master Station(MS) is the core of the system, which has the functions of supervising, data acquisition, processing and man-machine interface. In this paper, we suggested the optimal configuration of the medium/small scale DAS MS in accordance with the consideration of various requirements such as reliability, scalability flexibility, etc.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.39-39
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• 2010

There have been many efforts to utilize the outstanding properties of graphene for macroscopic applications such as transparent conducting films useful for flexible/stretchable electronics. However, the lack of efficient synthesis, transfer, and doping methods limited the scale and the quality needed for the practical production of graphene films. In this presentation, we introduce ultra-large scale (~30 inch) synthesis and roll-to-roll transfer of graphene films showing excellent electrical and physical properties suitable for practical applications. Considering the outstanding scalability/processibility of roll-to-roll and CVD methods and the extraordinary flexibility/conductivity of graphene films, we expect the commercial production and application electrodes replacing the use of ITO can be realized in near future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.121-122
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• 2012

• Journal of the Korean Society of Physical Medicine
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• v.3 no.3
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• pp.185-192
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• 2008

Purpose : The purpose of this study is to examine the effect of the electro-acupuncture stimulation into the multifidus for the lumbar flexibility improvement and pain reduction. The subjects were consisted of 20 women patients with chronic low back pain. Methods : 20 women patients with chronic low back pain voluntary participated for the research. 15 minute electro-acupuncture stimulation(frequency: 4Hz, Intensity: below threshold of pain) with Infra-red therapy, 3 times a week during 6 weeks period. Acupuncture application given to the patients' trigger point of the multifidus. The Application of multifidus was L3, L4, L5 spinal vertebra levels Short form McGill pain questionnaire (SFMPQ) was used to measure patient's pain level. Lumbar flexibility measurement was trunk flexion and trunk extension. Global Perceived Effect Scale(GPES) was used to measure recovery or worse of patient's condition. Results : SFMPQ was after treatment showed significantly decreased more than before stimulation treatment (P<.05). Lumbar flexibility was after treatment showed significantly increase more than before treatment(P<.05). GPES was after treatment showed significantly increased more than before treatment(p<.05). Conclusion : This study will be used as treatment method of patient with chronic LBP. The multifidus muscle in chronic LBP patients clinical significance. Most of chronic LBP patients have multifidus contraction pattern. So chronic LBP patients necessary multifidus muscle release treatment.

• Journal of muscle and joint health
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• v.14 no.2
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• pp.109-117
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• 2007

Purpose: The purpose of the study was to identify the effect of a self-exercise program on low back pain, abdominal-back muscle strength and waist flexibility in hospital nurses. Method: An experimental research design was employed. 43 subjects (20 in the experimental group and 23 in the control group) who worked in a general hospital in W city agreed to participate in this study. The intervention had 6 sessions with self-exercise program including flexion and extension demonstrated by a trained research assistant. A Visual Analog Scale was used to measure the subjective pain severity. Abdominal-back muscle strength was measured with a back strength dynamometer, while waist flexibility was gauged by the standing of the subject's upper body. Analysis included descriptive statistics, $x^2$ test, t-test and ANOVA. Result: The experimental group exhibited significantly decreased low back pain, an increase in abdominal-back muscle strength, and increased waist flexibility after 6 sessions. The experimental group were not significantly increased in abdominal-back muscle strength than the control group. Conclusion: These results suggest that further research is needed to replicate for verification of clinical validity with the methodological rigors, and to utilize the self-exercise program for care and prevention of low back pain.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.61-69
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• 2019

Purpose : The purpose of this study was to investigate the effects of Straight leg lifts (SLL) and double leg lowering (DLL) exercise on abdominal muscle activity, visual analog scale (VAS), and flexibility in patients with chronic low back pain (LBP). Methods : A total of 30 LBP patients were divided into two groups: those with SLL exercise group 15 (male=8, female=7) and those with DLL exercise group 15 (male=7, female=8). Before the intervention, the abdominal muscle activity, VAS, and flexibility were measured. After 4 weeks of intervention, the above variables were measured in the same way. The SLL exercise bends the leg $45^{\circ}$ in the supine position, and the DLL exercise was performed as opposed to SLL. At this time, the pressure biofeedback unit (PBU) was placed behind the lumbar to reduce the instability of the pelvis and muscles. The subjects were instructed to use the PBU to maintain the target pressure determined (40 mmHg) during the exercise. Results : The external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) were significantly different in the SLL and DLL group, and EO, IO, and TrA activity improved more significantly increased in the DLL than SLL group (p<.05). The results on the VAS and flexibility were significantly different both group (p<.05). However, there was no significant difference between the groups (p>.05). Conclusion : SLL and DLL exercises in patients with LBP were able to confirm the increased activity of the abdominal muscles, decreased pain, and increased flexibility of the waist. In addition, DLL exercise is more effective in patients with LBP in terms of muscle activity.

• Journal of Korea Trade
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• v.27 no.4
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• pp.1-18
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• 2023

Purpose - The purpose of this paper is to study how flexibility and mutuality in determining trade terms impact logistics efficiency in the context of relational theory. Additionally, the effect of relational contracts on logistical efficiency relative to the value of the goods being traded is investigated. Design/methodology - According to the relational contract theory, we developed 17 factors utilizing a 7-point Likert scale to measure variables related to flexibility, mutuality, logistics efficiency, and the added value of goods. The survey occurred over four months, and was distributed directly, and via email, phone, and online Google surveys. A total of 403 surveys were collected out of 1,800 distributed, and 380 were analyzed. The principal respondents were import/export companies and members of the Korea International Trade Association and the Korea Small and Medium Business Export-Import Association. The collected data were analyzed using frequency analysis, exploratory factor analysis, and correlation analysis using SPSS ver. 26.0 statistical software, and hypothesis test results were derived using Process Macro ver. 3.5. Findings - This study provides evidence that negotiation flexibility for trade terms affects the efficiency of the logistics process, and the mutuality of such arrangements is shown to be associated with the flexibility and efficiency of logistics processes. Additionally, it has been established that companies whose trade goods possess a low degree of added value may experience increased efficiency in logistics operations if they agree to trade terms that are both flexible and mutually beneficial with their counterparts. Originality/value - This study suggests that in an environment of rapidly shifting global logistics and unpredictable related costs, trade companies may be able to improve logistics efficiency by establishing flexible, mutually beneficial trade terms when entering into contracts. Furthermore, it is suggested that companies dealing in low-value-added products may improve the logistical performance of approaching trade from a perspective of relational contracts.

• Physical Therapy Korea
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• v.24 no.4
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• pp.38-45
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• 2017

Background: To improve muscle flexibility, static stretch is the most common type and is considered safe and effective for improving overall flexibility of muscles. During the stretch, the intensity is more likely to be determined by the degree of an athlete's pain and practitioner's skills rather than quantitative measures of stretch. It is necessary to determine the optimal intensity for the stretch. Objects: The purpose of this study is to explore the relationship between hand held dynamometer (HHD) and verbal rating scale (VRS) in comparison of the effects of continuance time on active (walking) and inactive (sitting) movement after static stretch. Methods: A cross-sectional study was conducted with a sample (n=62) recruited from a university. Participants were randomly assigned to 2 different groups (n=31 for each group) based on participants' positions either remaining in sitting or freely walking around for a series of re-assessments. Data was collected at pre-warm up, pre-stretch, post-stretch, and additional assessments at the time of 3, 6, 9, 12, 15, 20 and 30 minutes after the stretch. Results: Relationship between VRS and HHD scores represents very weak correlation (Spearman's p=-.16, p>.05). Pearson's correlation analysis was conducted following the logarithmic transformation of the two scores. Pearson's correlation after the transformation still showed a very low relationship and a poor linear relationship between the two scores (Pearson's r=-.18, p>.05). Conclusion: The optimal intensity for stretch cannot be solely determined by the subjective pain perception. The objective measurement such as HHD could be used in conjunction with the pain perception.

• PNF and Movement
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• v.18 no.3
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• pp.351-363
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• 2020

Purpose: The purpose of this study was to investigate the effects of Pilates exercise on the back pain index, pelvic tilt angle, and physical fitness of pregnant women with low back pain. Methods: All study participants, all of whom had pregnancy-induced back pain, were randomly assigned to either a Pilates exercise group (PG, n = 8) or control group (CG, n = 7). The PG performed a Pilates exercise for 50 minutes three times a week for eight weeks. The back pain scale and pelvic tilt angle were measured using a visual analogue scale and angulometer, respectively. Cardiopulmonary endurance, flexibility, and grip strength were measured to examine the physical fitness. The variables were analyzed using two-way repeated-measures ANOVA with the Holm-Sidak post hoc procedure. Results: Back pain in the PG significantly decreased from 4.69 ± 1.28 to 1.06 ± 0.94, whereas the CG showed significantly increased back pain from 2.63 ± 2.20 to 4.71 ± 2.56. The left pelvic angle in the PG showed a significant decrease from 13.94 ± 3.70° to 12.29 ± 2.95°, while the CG showed a non-significant difference from 13.07 ± 4.42° to 17.37 ± 3.13°. The right pelvic angle in the PG showed a significant decrease from 13.50 ± 4.47° to 10.34 ± 3.66°, while a non-significant difference in the CG from 44 ± 4.98° to 15.30 ± 3.61° was found. These results showed that the regular participation in Pilates exercise was effective in reducing the pelvic tilt angle. In terms of physical fitness, the PG showed a significant increase in cardiopulmonary endurance, flexibility, and grip strength. However, the CG showed any significance increase in those variables. Conclusion: Eight weeks of Pilates exercise was associated with a decrease in lower back pain, a maintained or reduced pelvic tilt angle, and increased cardiopulmonary endurance, grip strength, and flexibility in pregnant woman with lumbar pain.