• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.11
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• pp.1033-1041
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• 2011

In this paper, a collision avoidance maneuver frequency for the KOMPSAT-2 and the KOMPSAT-5 is analyzed. For the statistical prediction of the avoidance maneuver frequency, mission orbits, responsive time, accepted collision probabilities, and positional uncertainties of primary and secondary objects are considered. In addition, the collision avoidance maneuver frequency of the KOMPSAT-2 is compared to the case that NORAD catalog during one year is used to calculate that of the KOMPSAT-2. As a result, the collision avoidance maneuver frequency is one per year on average and effective factors on the statistical prediction of the avoidance maneuver frequency are investigated. Efforts to improve its prediction accuracy are also discussed.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.190-197
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• 2018

Background and Objectives : Positional OSAS is characterized by an apnea-hypopnea index (AHI) score >5, which, while sleeping in the supine position, is double that in non-supine position. This study was performed to compare the clinical characteristics of positional OSAS and non-positional OSAS patients, and the effects of the modified jaw thrust maneuver during drug-induced sleep endoscopy (DISE) between positional OSAS and non-positional OSAS patients. Materials and Methods : 68 positional OSAS patients and 19 non-positional OSAS patients were included. They all underwent full-night polysomnography and DISE. The modified jaw thrust maneuver was introduced during DISE. Airway structural changes induced by the modified jaw thrust maneuver were evaluated and documented. Results : There were no statistically significant differences in Friedman stage or tonsil grade, body mass index, Epworth sleepiness scale (ESS) score, blood pressure, AHI, or obstructive pattern between the positional and non-positional OSAS patients. However, mean arterial oxygen saturation (SaO2), lowest SaO2, and total arousal index values were more severe in the non-positional OSAS patients. After introduction of the modified jaw thrust maneuver, retrolingual level obstruction showed a tendency toward a higher rate of airway opening in positional OSAS patients than in non-positional OSAS patients. Conclusions : The effects of a mandibular advancement device (MAD) can be estimated by carrying out a modified jaw thrust maneuver during DISE. The tendency toward a higher rate of airway opening in positional OSAS patients than non-positional OSAS patients in retrolingual level obstruction after jaw thrust maneuver introduced during DISE may be clinically important for MAD.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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• pp.79-87
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• 2021

Objective: To compare the effects of lumbar dysfunction and balance when office workers with chronic back pain performed the abdominal drawing-in maneuver. Methods: A total of 16 office workers with chronic low back pain were included in this study. The participants were randomly divided into two groups: the general and abdominal drawing-in maneuver groups. The intervention was applied for 6 weeks, 3 times a week, 70 min per day. Participants in the general exercise group(n=8) performed the general physical therapy and lumbar flexibility exercise, whereas those in the abdominal drawing-in maneuver group(n=8) performed the general physical therapy and lumbar stabilization exercise using abdominal drawing-in maneuver(3 times/week for 6 weeks). All tests, were the Korean Oswestry disability index (KODI) and balance ability, were completed pre and post-intervention. Results: Significant improvements in the KODI and balance ability test were observed in the abdominal drawing-in exercise group (p<.05), whereas no significant changes (p>.05) were observed in the general exercise group. Conclusion: This study revealed that abdominal drawing-in maneuver can effectively improve the lumbar dysfunction and balance ability of office workers with chronic back pain.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.205-211
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• 2022

Purpose: This study investigated the effects of an intervention that combined the abdominal drawing-in maneuver and frequency-specific neuromuscular electrical stimulation on changes in trunk muscle activity, muscle fatigue, and balance in stroke patients. Methods: Thirty stroke patients were randomly assigned to two groups. Fifteen subjects were assigned to group I which performed the abdominal drawing-in maneuver combined with low-frequency neuromuscular electrical stimulation and the other 15 subjects to group II where the abdominal drawing-in maneuver was combined with high-frequency neuromuscular electrical stimulation. Muscle activity and fatigue were measured using surface electromyography before the intervention. Balance was measured using the Trunk Impairment Scale and re-measured after six weeks of intervention for comparative analysis. Results: Both groups showed a significant increase in muscle activity and balance (p<0.05), and there was no significant difference between the groups (p>0.05). In the changes in muscle fatigue, only the experimental group II showed a significant increase in muscle fatigue (p<0.05). The difference between the groups was statistically significant (p<0.05). Conclusion: It was confirmed that among stroke patients, the combination of the abdominal drawing-in maneuver and low-frequency neuromuscular electrical stimulation was more effective in changing the muscle activity and balance of the trunk by minimizing the occurrence of muscle fatigue compared to the combination of the abdominal drawing-in maneuver and high-frequency stimulation. These results can be used as basic data for clinical trunk stabilization training.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1392-1395
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• 2004

In order to successfully develop attitude and orbit control subsystem(AOCS), AOCS engineer performs hardware selection, controller design and analysis, control logic and interface verification on electrical test bed, integrated system test, polarity test, and finally verification on orbit after launching. Attitude and orbit control subsystem for KOMPSAT-2 consists of standby mode, sun mode, maneuver mode, science mode, and power safe mode to stabilize and to control the spacecraft for performing the mission. The sun mode is usually divided into sun point submode, earth search submode and safe hold submode. The maneuver mode is divided into attitude hold submode and ${\triangle}$ V submode, while the science mode divided into science coarse submode and science fine submode. Moreover, it is added to back-up mode which uses wheels as an actuator for sun mode and maneuver mode. In this paper, we describe the controller design process and the performance of the design results with respect to the sun mode and the maneuver mode based on thrusters as an actuator using on flexible model.

• Journal of Korean Biological Nursing Science
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• v.11 no.1
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• pp.68-76
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• 2009

Purpose: The purpose of this study was to evaluate the hemodynamic changes in degree and duration that occur during Valsalva maneuver (VM). Furthermore, we wanted to investigate the patterns and mechanisms of physiological hemodynamic control. Method: Thirty six healthy college students were recruited from Y university. Each participant was provided with written informed consent. Blood pressure (BP), heart rate (HR), cardiac output (CO) were continuously recorded using the Finometer. Result: During the phase I of VM, means of systolic and diastolic pressures were increased by 32.15% and 38.28%, respectively, compared with basal values. HR and CO were decreased by 9.91% and 13.01%, respectively. Immediately after the maneuver (phase III), systolic and diastolic pressures were decreased by 5.05% and 6.24%, respectively, compared with those obtained in the phase II. HR and CO were elevated by 13.33% and 11.93%, respectively, compared to the levels of earlier phases. BPs were represented with overshoot in the phase IV, and recovered by baseline values about 20 sec after VM. Conclusion: These results demonstrated that hemodynamic changes are variable in the event of VM even in healthy humans. It will be valuable to accumulate more quantitative hemodynamic information in special populations such as the elderly and the patients with cardiovascular problems.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.719-728
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• 2017

This paper proposes a synthesis of new guidance law to generate an evasive maneuver against enemy's missile interception while considering its impact angle, acceleration, and field-of-view constraints. The first component of the synthesis is a new function of repulsive Artificial Potential Field to generate the evasive maneuver as a real-time dynamic obstacle avoidance. The terminal impact angle and terminal acceleration constraints compliance are based on Time-to-Go Polynomial Guidance as the second component. The last component is the Logarithmic Barrier Function to satisfy the field-of-view limitation constraint by compensating the excessive total acceleration command. These three components are synthesized into a new guidance law, which involves three design parameter gains. Parameter study and numerical simulations are delivered to demonstrate the performance of the proposed repulsive function and guidance law. Finally, the guidance law simulations effectively achieve the zero terminal miss distance, while satisfying an evasive maneuver against intercept missile, considering impact angle, acceleration, and field-of-view limitation constraints simultaneously.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.107-119
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• 2013

We study three axis attitude control method including two axis high agile maneuver using four reaction wheels and two control moment gyros. We investigate singularity conditions due to two control moment gyros and propose singularity escape method. Based on this, we propose actuator control algorithm for high agile maneuver. Also, we propose actuator momentum management method which preserves momentum of reaction wheels and control moment gyroscopes before and after satellite attitude control. Through numerical simulation, we show that our method achieves three axis attitude control including two axis high agile maneuver and preserves actuators' momentum.

• PNF and Movement
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• v.15 no.3
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• pp.217-226
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• 2017

Purpose: The purpose of this study was to determine the effects of a modified abdominal draw-in maneuver on trunk stability and functional capacity as well as pain in patients with chronic low back pain. Methods: The study included 3 patients with chronic low back pain who volunteered to participate. The modified abdominal draw-in maneuver included a posterior pelvic tilt, a traditional abdominal draw-in maneuver, and a vibration sensory feedback device. Voluntary abdominal contraction using the vibration sensory feedback device was performed by the subjects for more than 1 hour per day, 5 times per week, for 6 weeks along with common low back pain treatment. Electromyographic signals in the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles were measured to compare muscle activation. The degree of pain was measured using the visual analogue scale (VAS), and functional capacity was measured using the Korea Oswestry Disability Index (K-ODI). All results were compared to the means before and after intervention. Results: After the intervention, the RA, EO, and IO showed increased muscle activation and the ES showed decreased muscle activation. The visual analogue scale decreased after intervention and the K-ODI decreased after intervention. Conclusion: Modified abdominal draw-in maneuvers in daily life combined with therapeutic exercises may be effective in relieving pain and dysfunctions in chronic low back pain patients.

• The Journal of Korean Physical Therapy
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• v.24 no.1
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• pp.1-6
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• 2012

Purpose: The grip strength is influenced by various factors, such as position of the upper extremity, characteristics of the hand, and general physical condition. In this study, we investigated whether abdominal muscle activity in combination with the abdominal drawing-in maneuver has any effect on the grip strength in healthy young adults. Methods: This study included 31 healthy subjects (16 males, 15 females). We used surface electromyography and pressure bio-feedback unit for this experiment. All Subjects were placed in a cock-lying position with comfort and the grip strength was measured. On the following day, the pressure bio-feedback unit was placed beneath their fifth lumbar vertebra, and the, grip strength was measured again. This time, the measurement was taken while drawing-in their abdomen below the navel gently and gradually, while maintaining a neutral pelvic position. Results: The grip strength was significantly increased when subjects performed the drawing-in maneuver than when they were comfortable (p<0.05). In addition, activations of the rectus abdominal muscles significantly increased (p<0.05). Conclusion: In the current study, we found that abdominal muscle activity, in combination with the abdominal drawing-in maneuver, affected the grip strength, positively. Therefore, we suggest that this result should be considered when evaluating the grip strength.