• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.235-244
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• 1998

The solutions of orbital maneuver problem using the sliding mode control in the presence of the erath gravitational perturbations is obtained. Especially, the optimization of consuming fuel for maneuver is performed. The impulsive solution to Lambert's problem using the combined equation method to minimize total ${\Delta}V is used for the desired orbit and the maneuver times. Two-step sliding mode control method is introduced for satisfying the boundary conditions of finite-thrust rendezvous problem at the end of maneuver time. Using the new approach to the orbit maneuver problem, two-step sliding mode control, orbit maneuvers are processed. The solutions to a rendezvous using the optimal control are obtained, and they are compared to the results by two-step sliding control.According to the new approach for orbit maneuver, the thrust-coast-thrust type controller is obtained to make satellite to track desired Lambert's orbit, and the total ${\Delta}V$ required for maneuver is resonable in comparison with the impulsive solution to Lambert's problem. The final state variables, also are close to the boundary conditions at the end of maneuver times.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.12
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• pp.658-662
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• 2018

Background and Objectives The early assessment of treatment is not done for benign paroxysmal positional vertigo (BPPV) since the well-known phenomenon of fatigability after a repeated positional test can mimic successful treatment. The aim of this study is to evaluate the clinical implication of 'fatigability' after Epley maneuver and to identify the therapeutic efficacy of Epley maneuver in posterior canal BPPV (PC-BPPV). Subjects and Method This study was prospectively conducted by two dizziness clinics on 51 consecutive patients diagnosed with PC-BPPV. All patients included in the study received Epley maneuver treatment. The therapeutic results were reassessed immediately after a single trial of Epley maneuver. After 30 minutes, results were reassessed repeatedly to confirm the fatigability of diagnostic procedure immediately after treatment. If the treatment was not successful after 30 minutes, Epley maneuver was repeatedly performed until complete resolution. Results Immediately after the first maneuver, 45 of 51 (88.2%) patients had neither vertigo nor nystagmus during the positional test. All patients demonstrated complete resolution after receiving one to three Epley maneuvers on the day of diagnosis. 'Fatigability (false negative result)' was confirmed for only one case (1 of 6 patients, 16.7%), in which nystagmus was observed after 30 minutes but not identified immediately after the first Epley maneuver. Conclusion The therapeutic efficacy of Epley maneuver is very high in PC-BPPV. Considering the possibility of fatigability when reassessment is performed immediately after therapeutic maneuver, clinicians should avoid assessing the outcome immediately after treatment in patients with PC-BPPV.

• Journal of Korean Physical Therapy Science
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• v.27 no.3
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• pp.75-83
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• 2020

Background: The effect of the Valsalva maneuver applied in resistance exercise has shown contradictory results. This study aims to investigate the effect of the Valsalva maneuver on resistance exercise by examining the changes that occur by applying the Valsalva maneuver during trunk flexion and extension resistance exercise in healthy adults. Design: Randomized controlled trial. Methods: 34 healthy adults were conveniently recruited. According to the with or without Valsalva maneuver, the flexion and extension of the trunk were measured and evaluated. Results: Paired t test showed that there was a statistically significant difference in maximum torque of trunk flexion in the resistance exercise with Valsalva maneuver. However, there was no statistically significant difference in trunk extension (p<.05), in the total and average work of trunk flexion and extension (p<.05). Conclusion: The results of this study in which the difference in the amount of exercise according to the application of the Valsalva maneuver was not significant, show that the practice of the Valsalva maneuver, which has a risk of injury, should be avoided in rehabilitation exercises.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.513-523
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• 2013

PURPOSE: The purpose of this study was to investigate characteristics of the forced pulmonary function test effect and abdominal muscles activation by combined complex exercise with abdominal drawing-in maneuver training of chronic stroke patients. METHODS: 14 post stroke patients(10 males and 4 females) involved voluntary this study and we divided two groups into CEG(complex exercise group) and CEAG (complex exercise and abdominal drawing-in maneuver group).(n=7, per goup). Each groups implicated the 2 times, 30minute exercises for 6 weeks a day. The CEAG performed the complex exercise 15 minutes and 15 minutes of abdominal drawing-in maneuver. For data analysis, the mean and standard deviation were estimated; non-parametric independent t-test was carried out. RESULTS: According to the study, in the combined complex exercise with abdominal drawing-in maneuver group, FVC and activation of transversus abdominis/internal oblique were statistically significant difference compared to the complex exercise group. CONCLUSION: These results indicate that the combined complex with abdominal drawing-in maneuver was efficient in enhancing abdominal muscles activation and pulmonary function of chronic stroke patients.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1676_1677
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• 2009

This paper uses the softstarter function of the inverter in the place of business where the flow control is possible, multi maneuver method as the application (with 1 inverter various pump maneuver/standstill which is soft) box the plan which prevents the small hand of the equipment which is caused by maneuver electric current presented.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.108-113
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• 1991

In this paper, an improved method for tracking maneuvering target is proposed. The proposed tracking filter is constructed by combining the input estimation approach with the variable dimension filtering approach. In this approach, the filter also provides the estimated time instant at which target starts maneuver, when the target maneuver is detected. Using this estimated maneuvering time, the maneuver input is estimated and the tracking system changes to the maneuver model. Simulations are performed to demonstrate the efficiency of the proposed tracking filter.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.845-849
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• 1992

The disturbance and time delay can often cause a significant error in the estimation of trajectory of a underwater vehicle. The time delay considered in this study is due to the delayed rudder response to the rudder input from the guidance control part. The simulation tests are performed on maneuver with constant rudder angle, zigzag maneuver, dive-climb maneuver, and corridor pattern maneuver. The results are compared with those of without delay cases.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.496-499
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• 1995

In this paper, a new detection scheme, the detectable maneuver set (DMS) scheme, is proposed by incorporating the trade-off property between target maneuver magnitude and detection time delay. With this new detection scheme, small maneuvers can be effectively detected without enlarging window size. Simulation results show that the proposed DMS scheme gives better tracking performance.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.653-658
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• 1994

This paper presents numerical analyses of the low speed yo-yo maneuver of an aircraft to determine controls of thrust, bank-angle and angle-of-attack in the subsonic region in terms of the optimal control theory. Minimum-time flight paths are numerically calculated to overtake an opponent aircraft flying in some steady-state level turnings under several assumptions: both of aircraft are point masses and maneuver in the 3-Dimensional space. Their weights are considered constant in the maneuver. As a result of the analyses, the effectiveness of the low speed yo-yo maneuver is shown.