• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.282-285
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• 1999

Fabrication and pakaging method for low delve voltage and 10Gbps Ti diffused waveguide LiNbO$_3$ optical intensity modulator are described. Optical waveguides were prepared by conventionaly electron-beam evaporation and Ti-indiffusion into Z-cut plate LiNbO$_3$. Traveling-wave electrodes were used for obtaining the wideband frequency response and impedance matching. Microwave effective index and characteristic impedance measured by time domain reflectometry and compared with the calculated value by conformal mapping. The characteristics of 10Gbps modulator at the 1550nm wavelength are as follows : perfect modulation voltage Is about 5V, optical insertion loss Is about 5dB, 3-dB bandwidth is 10GHz, and characteristic impedance is about 50$\Omega$.

• Journal of Navigation and Port Research
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• v.32 no.4
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• pp.271-277
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• 2008

When performing steering by an autopilot (automatic steering gear), a sensitivity adjustment is mainly determined by P value and D value. These values differ in the optimal combination by model of ship and external forces. This research was carried out simulation case studies and examined movement of Pure Car Carrier, which easily received ship by wind pressure influence in low speed We investigated the relation of horizontal migration(transfer) of ship's body and P-D value. Based on it, four parameters of P-D at approaching berth could be suggested Hence there were suggestions of parameters; Distance to maximum lee point, Time to maximum lee point, Time to return to original course and Time to 300th second. The correlation of these parameters and P-D value were also considered. As a result, we think that this index, like formulated P-D, leads to an easy and safe navigation by utilizing these indices.

• Clinical and Experimental Pediatrics
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• v.65 no.2
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• pp.65-72
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• 2022

Cholesterol, the main structural molecule of cell membranes, is involved in essential functions of the human body. Dyslipidemia is an established risk factor for cardiovascular diseases (CVDs) that is observed even in childhood. To reduce the risk of CVDs in children, several clinical guidelines have been published for the management of pediatric dyslipidemia. However, pediatric dyslipidemia is also associated with several health problems other than CVDs. This article reviews the current data on dyslipidemia-related pediatric health issues. There is strong evidence that low serum vitamin D levels, asthma, and mental health problems may be associated with dyslipidemia in the pediatric population regardless of body mass index. This review also highlights the need for further large-scale population-based studies in the Korean pediatric population to establish effective strategies for promoting children's health.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.333-343
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• 2024

This study aimed to investigate whether inhaling the aroma of essential oils could alleviate physiological stress responses and mimic the effects of forest therapy in urban settings. Briefly, 31 participants underwent stress index assessments for two days and inhaled the selected plant essential oils. The effects of this treatment on physiological responses were determined through electroencephalogram (EEG) and heart rate variability (HRV) measurements taken before and after inhaling the aroma of essential oils, extracting results for low frequency (LF) and high frequency (HF) components of HRV, as well as 𝜃 and 𝛼 brainwave activities. The results indicated that lavender oil did not yield significant differences, whereas pine, chamomile, and cypress oils exhibited significant differences in effects. Overall, stress relief was associated with enhanced 𝜃 and 𝛼 brainwave activities, a decrease in the LF component and an increase in the HF component of HRV. Among the essential oils studied, pine oil was the most effective. These findings underscore the potential of plant essential oils in replicating the therapeutic benefits of forest therapy, even in urban environments. Further investigations into their utilization are warranted to better understand and harness their therapeutic potential.

• Korean Journal of Optics and Photonics
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• v.6 no.2
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• pp.148-155
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• 1995

The low loss single-mode $Al_{0.042}Ga_{0.958}As/GaAs/Al_{0.042}Ga_{0.958}As$ strip-loaded waveguides had been designed using an effective index method and fabricated using a MOCVD technique and chemical wet etching method. The propagation loss and facet reflectivity were measured by the Fabry-Perot resonance method and sequential cleaving experiment at $1.31{\mu}m$ wavelength. As a result, the propagation loss is as low as 0.62 dB/cm and the facet refiectivity(R) equals to 0.299 for straight waveguides with width $ w=4.1{\mu}m$..

• Journal of Acupuncture Research
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• v.33 no.4
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• pp.219-224
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• 2016

Objectives : The purpose of this study was to report the clinical effects of needle-embedding acupuncture therapy combined with Korean medicine on a lumbar herniated intervertebral disc. Methods : We treated one patient with a lumbar herniated intervertebral disc with needle-embedding acupuncture therapy combined with Korean medical treatment. We checked the numeric rating scale(NRS), oswestry low back pain disability index(ODI) and straight leg raising test(SLRT). Results : In this case, the numeric rating scale decreased, while the straight leg raising test results improved. Conclusion : Needle-embedding acupuncture therapy could be effective for pain-reduction for a lumbar herniated intervertebral disc.

• PNF and Movement
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• v.14 no.2
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• pp.139-147
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• 2016

Purpose: This study examined whether a single application of a lumbar flexion muscle energy technique (MET) could significantly influence pain, functional status, and range of motion in chronic back pain patients with restricted active trunk flexion. Methods: Twenty volunteers were randomly assigned to either a control group or an experimental group. Ten subjects in the control group received no treatment. Ten subjects in the experimental group received five sessions with the muscle energy technique, five times per week for two weeks. Outcomes were measured before and after two weeks of treatment in both groups. Pain intensity was assessed using a visual analogue scale (VAS). Range of motion was measured using the sit-and-reach test (SRT). Functional disability levels were assessed using the Korean version of the Oswestry Disability Index (KODI). Results: The experimental group showed a significant difference in VAS, KODI, and SRT between pre- and post-treatment (p < .05), while the control group showed no significant changes. The changes in VAS, ODI, and SRT were statistically significant between the groups pre- and post-treatment (p < .05). Conclusion: This muscle energy technique is clinically effective for chronic low back pain patients.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.4
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• pp.189-202
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• 2009

Objectives : This study was performed to evaluate the effects of Chuna treatment (Saban-method technique) on acute lumbar sprain patients with limited range of motion(LOM). Methods : Three patients suffered from acute lumbar sprain with LOM, were treated with Chuna therapy(Saban-method technique), acupuncture, herbal medicine, physical therapy and measured by VAS(Visual Analogue Scale) and ODI(Oswestry Disability Index). Results : After Chuna treatment and oriental medical treatments, we found out a recovery from three patients suffering from acute low back pain with LOM. Conclusions : Through this study, we suggest that Chuna treatment(Saban-method technique) and oriental medical treatments was effective to cure acute lumbar sprain patient with LOM.

• Physical Therapy Rehabilitation Science
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• v.11 no.1
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• pp.78-87
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• 2022

Objective: The purpose of this study was to investigate the effect of high-intensity complex exercise program using whole-body vibration (WBV) and respiratory resistance on pain and dysfunction, psychosocial level, balance ability, and pulmonary function in low back pain (LBP) patients with high obesity. Design: A randomized controlled trial Methods: A total of 44 LBP patients withhigh obesity (body mass index, BMI≥30kg/m²) were randomly assigned to an experimental group (n=22) and a control group (n=22). Both groups underwent a lumbar stabilization exercise program. In addition, the experimental group implemented the high-intensity complex exercise program combined with WBV and respiratory resistance. In order to compare the effects depending on the intervention methods, numeric pain rating scale (NRPS), Roland-Morris disability questionnaire (RMDQ), fear-avoidance beliefs questionnaire (FABQ), balance ability, and pulmonary function were used for measurement. Results: Both groups showed significant differences in NRPS, RMDQ, FABQ, balance ability before and after intervention (p<0.05). In addition, the experimental groupshowed significant difference in the amount of change in RMDQ, balance ability and pulmonary function values than the control group (p<0.05). Conclusions: High-intensity complex exercise program using WBV and respiratory resistance has been proven to be an effective and clinically useful method to decrease dysfunction, increase balance ablilty, and pulmonary function for LBP patients with high obesity.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.343-350
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• 2013

PURPOSE: The purpose of this study was to compare the effects of a combined non elastic taping and lumbar stabilizing exercise against lumbar stabilizing exercise only during the lumbar stabilizing exercise in chronic low back pain. METHOD: Thirty-one patients of low back pain were randomly allocated to 2 groups: lumbar stabilizing exercise group (n=16) and nonelastic taping group(n=15) with lumbar stabilizing exercise. Taping and stabilizing exercise were performed twice a week for 4 weeks. The patients were assessed using by visual analog scale (VAS) and Korean version of Oswestry disability index (KODI). The measurements of each patients were measured before the intervention and 2 weeks post-experiment and 4weeks after the intervention. All data were analyzed using by SPSS 12.0 software for Window, the experimental data was analyzed using by paired samples t-test and repeated ANOVA. All statistical tests in this study were conducted at the .05 level of significance. RESULTS: The results of this study are in the nonelastic taping group, significant difference were found in th VAS between pre-test and post-test (p<.05). In addition, there were significant differences in the VAS between the two groups at post-test(p<.05). And in the nonelastic taping group, significant difference were found in the KODI between pre-test and post-test (p<.05). However, there were no significant differences in the KODI between the two groups at post-test (p<.05). CONCLUSION: These findings suggest that combination of nonelastic taping and lumbar stabilizing exercise is more effective for low back pain than stabilizing exercise alone. In conclusion, this study indicates that stabilizing exercise combined with nonelastic taping would be recommended in the clinic.