• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.235-244
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• 1998

인공위성의 궤도조정에 사용되는 소모연료의 최적화를 위해, 비 선형 제어 시스템인 슬라이딩 제어 기법을 사용하여 지구 비대칭 중력장에 의해 섭동력을 고려한 궤도조정 문제의 해를 구하였다. 결합 방정식을 이용한 해법을 통해 총 속도 변화량이 최소가 되는 Lambert 궤도를 목표궤도로 설정하고 그에 따른 궤도조정 시간을 결정하였다. 결정된 궤도조정 시간이 종료되는 시점에서 제한된 추력에 의해 제어되는 인공위성의 상태 백터가 경계조건과 일치되도록 하기 위하여, 슬라이딩 제어를 반복적으로 사용하는 2단 슬라이딩 제어기법을 도입하였으며, 이를 인공위성 랑데뷰 문제에 적용하여 최적 에어방법에 의한 결과와 비교하였다. 새롭게 제안된 제어방법을 이용한 궤도조정은 이상적인 전이궤도인 Lambert 궤도와 근접한 궤도를 갖도록 하는 thrust-coast-thrust 형태의 추력을 나타내었으며, 이 때 필요한 속도의 변화량은 Lambert's two-impulsive 방법에 의한 값에 매우 근접한 값을 나타내었다. 또한 궤도조정 시간이 종료되었을 때, 궤도의 모든 상태변수들이 최종 경계조건과 거의 일치되는 결과를 얻을 수 있었다.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• 제61권12호
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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.

• 대한물리치료과학회지
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• 제27권3호
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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.

• 대한물리의학회지
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• 제8권4호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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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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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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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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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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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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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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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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• 제33권4호
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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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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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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.