• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2005년도 추계학술발표회
• /
• pp.602-603
• /
• 2005

• International Journal of Advanced Culture Technology
• /
• 제7권1호
• /
• pp.209-215
• /
• 2019

In order to provide a safe free-weight-training environment to people without workout trainers, we suggest a smart bench press machine with an automatic weight control system sensitive to user tiredness. Physical weight plates on the machine are replaced with a hydraulic cylinder as a press load and the cylinder knob is coupled with a step motor to change its tensile force automatically in-between lifting exercises. Three subjects participated to verify the usability of the smart bench press machine. They were asked to lift a 6-RM press load 10 times with 3 different lifting conditions: 1) no assistance, 2) a human assistance, and 3) the automatic weight control. All subjects were not able to complete the 10 sets without assistance due to tiredness, but they finished the full sets under the two assistive conditions. Average lifting speeds under the automatic weight control condition showed the most consistent level. Normalized quasi-tension data based on surface electromyogram signals of both Pectoralis Majors revealed that the subjects maintained the target muscle activation level above 50% but not more than 80% throughout the 10 sets. Therefore, the smart bench press machine is expected to both keep pace with the lifting exercise and reduce risk of injuries due to excessive muscle tensions.

• Journal of applied mathematics & informatics
• /
• 제7권2호
• /
• pp.409-438
• /
• 2000

In this paper we develop a new procedure to control stepsize for Runge- Kutta methods applied to both ordinary differential equations and semi-explicit index 1 differential-algebraic equation In contrast to the standard approach, the error control mechanism presented here is based on monitoring and controlling both the local and global errors of Runge- Kutta formulas. As a result, Runge-Kutta methods with the local-global stepsize control solve differential of differential-algebraic equations with any prescribe accuracy (up to round-off errors)

• 한국작물학회지
• /
• 제57권2호
• /
• pp.106-112
• /
• 2012

본 연구는 $CO_2$농도와 온도가 상승함에 따라 인삼의 생육반응 및 광합성 특성의 변화를 알아보기 위해 실험하였다. 유리 온실 안에 대조구(대기중 $CO_2$ 농도)와 $CO_2$ + 온도상승구(750-800 ppm, $2^{\circ}C$ 상승)로 나누어 비교하였으며 다음과 같다. 1. 인삼의 개엽율은 1년생 인삼을 이식한 후 1주일 이후인 4월 6일에 $CO_2$ + 온도상승구의 개엽율이 대조구보다 더 높았다. 그러나 최종 개엽율은 $CO_2$ + 온도상승구간 차이가 없었다. 2. 꽃이 나오는 시기는 대조구보다 $CO_2$ + 온도상승구가 3일 빨랐고, 열매관찰시기와 열매 성숙시기는 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 3. 인삼의 줄기길이는 대조구보다 $CO_2$ + 온도상승구에서 길었고, 잎수는 대조구보다 $CO_2$ + 온도상승구에서 많았다. 4. 지하부 생량무게는 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 5. 광합성은 모두 대조구보다 $CO_2$ + 온도상승구가 높았다. 대조구 내에서는 년도별 광합성이 차이가 있었다. 하지만 $CO_2$ + 온도상승구에는 1년생과 2년생 간 차이가 없었다. 6. 증산률은 대조구와 $CO_2$ + 온도상승구에서 모두 년생간 차이가 있었다. 1년생은 대조구보다 $CO_2$ + 온도상승구가 높았고, 2년생은 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 7. 수분이용효율은 대조구와 $CO_2$ + 온도상승구에서 모두 1년생과 2년생간 차이가 있었다. 1년생은 대조구와 $CO_2$ + 온도상승구간 차이가 없었고, 2년생은 대조구 보다 $CO_2$ + 온도상승구가 높았다. 이상으로 볼 때 지구온난화는 인삼의 생육과 생리 생태학적 반응에 다소 긍정적인 영향을 준다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1001-1005
• /
• 2003

Most electronic chassis control systems until today have been designed with optimization on its own performance. Recently, however. importance of the global chassis control (GCC) concept that aims to achieve optimal performance on a global basis is more emphasized than ever, as the x-by-wire technology is rapidly progressing. In this research, a study has been done for developing a GCC logic for combining longitudinal, lateral, and vertical chassis control subsystems. A simulation has been performed to investigate interactions among the subsystems, and based upon the results, a GCC logic has been developed. The logic has been tested under various driving conditions. and the results have been compared with those from implementing subsystems without any GCC logic.

• 복합신소재구조학회 논문집
• /
• 제6권1호
• /
• pp.51-58
• /
• 2015

Global buckling is a bending of pipeline and it occurs when the stability of pipeline is distributed by excessive axial force. Subesea pipeline is subjected to axial force induced by temperature and pressure from well and resulting phenomena should be controlled in appropriate manner. Global buckling of subsea pipeline is still ongoing research subject and is studied various organization. In this study, various control methods such as buoyancy module, sleeper, and snake lay for global buckling of subsea pipeline were numerically investigated with various design parameters. From the numerical simulation results, the global buckling control method using sleepers shows better results than buoyancy module and snake lay control methods in the sense of combined stress after buckling. Furthermore, the global buckling of full scale pipeline of 80km with uneven seabed profile were successfully managed when the sleeper was installed.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
• /
• pp.785-790
• /
• 1994

The active noise control which regards the acoustic power as a target function to be minimized, is analyzed to test its feasibility of which simplifies the measurement system compared with the global acoustic energy based active noise control system. In fact, it is found that the acoustic power based active noise control strategy is equally likely as good as the global acoustic energy based active noise control method if the acoustic field of interest is diffusive or very low model density one. In the intermediate model density field, we also demonstrate that the power based control gives the similar results as the energy based control in terms of global sound energy reduction for the lightly damped enclosure which might be most important system in practical application. From all the theoretical and power based control strategy is dependent on the characteristics of the acoustic field to be controlled; i.e., the model density distribution, the degree of reverberation, and on the strength of modal interaction of the control source with the primary source; i.e., the location of control source.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
• /
• pp.119-122
• /
• 1996

The recently proposed control method using a Lyapunov-like function can give global asymptotic stability to a system with mismatched uncertainties if the uncertainties are bounded by a known function and the uncontrolled system is locally and asymptotically stable. In this paper, we modify the method so that it can be applied to a system not satisfying the latter condition without deteriorating qualitative performance. The assured stability in this case is uniform ultimate boundedness which is as useful as global asymptotic stability in the sense that it is global and the bound can be taken arbitrarily small. By the proposed control law we can deal with both matched and mismatched uncertain systems. The above facts conclude that Lyapunov-like control method is superior to any other Lyapunov direct methods in its applicability to uncertain systems.

• 근관절건강학회지
• /
• 제28권1호
• /
• pp.50-60
• /
• 2021

Purpose: The purpose of this study is to verify the effect of improving global health nursing competency, understanding of international development cooperation and satisfaction of education for nursing students through the course of global health in nursing. Methods: This study is a design of similar experiments before and after the non-equivalent control group to verify the difference in degree between global health nursing competency and understanding of international development cooperation by the course of global health in nursing of nursing students. Results: The degree of global health nursing competency of the experimental group that took the course of global health in nursing has significantly improved compared to the control group that did not participate, and a total of 30 detailed items showed significant differences. Conclusion: In this study, the global health nursing competency and understanding of international development cooperation have improved since nursing students took the course of global health in nursing. It suggests that the development and evaluation of nursing curriculum is necessary at a time when the global health nursing competency needs to be improved.

• Journal of Power Electronics
• /
• 제15권6호
• /
• pp.1559-1566
• /
• 2015

The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.