• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.51-57
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• 2020

A propeller-based seesaw system is a system that can represent one of axis of four propeller drones and its stabilization has been replaced by intelligent control system instead of often used control methods such as PID and state space. Today, robots are increasingly use machine learning methods to adapt to their environment and learn to perform the right actions. In this article, we propose a Q-learning-based approach to control the stability of a seesaw system with a propeller. From the experimental results that it is possible to fully learn the balance control of a seesaw system by correctly defining the state of the system, the actions to be performed, and the reward functions. Our proposed method solves the seesaw stabilization.

• Korean Journal of Child Studies
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• v.32 no.4
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• pp.185-202
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• 2011

The purpose of this study was to examine the effects of the Seesaw & Swing Early Intervention Program on the positive changes of young children from low-income families. The Seesaw & Swing program was developed by the Community Chest of Korea (Hwang et al., 2009). The subjects for this study consisted of 534 3~6-year olds (177 in the service group, 357 in the control group) from low-income families. The instrument used was the Vineland Adaptive Behavior Scales, second edition (Sparrow, Cicchetti, & Balla, 2005). The results of this study indicated that the Seesaw & Swing intervention program produced positive effects in all of the domain areas under examination : namely, the communication abilities, life skills, socialization, physical development, and adaptive behaviors of young children. In conclusion, the Seesaw & Swing Early Intervention Program for young children from low-income families can be said to be an effective early intervention program which goes some way towards ending the intergenerational transition of poverty in Korea.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.974-980
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• 2008

Generally. most of the physical systems affected by disturbance or incomplete knowledge are complex and highly nonlinear. To control under these circumstances. many researches are ongoing in modern control theory recently. But the researches need apparatuses. which can verify the controller for being not damaged the real plant. In this paper. therefore. a seesaw system is considered control system to analyze and apply the control theory. A seesaw system consists of a moving cart on the rail and seesaw frame made to demonstrate the effectiveness of the control theory. The system has balancing and positioning problems. and the driving force is applied on the DC motor of cart. but not on the pivot. The purpose of control is to maintain an equilibrium of seesaw frame in spite of an allowable disturbance. Computer simulations are given to illustrate the control performance of the proposed scheme.

• Journal of the Korean Home Economics Association
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• v.51 no.1
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• pp.97-106
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• 2013

The purpose of this study is to examine the effects of the Seesaw & Swing early intervention program on the positive changes of mothers with young children who come from low-income families. It measures their child-rearing efficacy and their child-rearing behaviors. The Seesaw & Swing early intervention program was developed by the Community Chest of Korea [13]. The subjects for this study consisted of 96 mothers (49 in the service group, 47 in the control group) from low-income families. The instruments used were the child-rearing efficacy scale [4] and the child-rearing behavior scale [29]. The results of this study indicated that the Seesaw & Swing early intervention program produced positive effects in child-rearing efficacy as well as in child-rearing behaviors: namely, healthy-rearing abilities, guidance abilities, and discipline abilities in child-rearing efficacy; and affection, rational guidance, authoritative control, encouragement and concern in child-rearing behaviors. In conclusion, for mothers with young children coming from low-income families, the Seesaw & Swing early intervention program can be said to be an effective parent education program, which goes some way towards ending the intergenerational transition of poverty in Korea.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.185-188
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• 2009

In this paper, Position Controller for balance of Seesaw System design using PID Algorithm. Seesaw System is that it's system use widely to analyze of ship or flight dynamics, Inverted Pendulumand, Robot System, manage system for theory of modern control system and all sorts of analysis. In case of Seesaw System, it's necessity that understand and analysis of system and correct selection of parameter because the system is strong nonlinear control system. It guarantees efficiency and stability to adapt quickly for disturbance or change of controller from PID Algorithm of guarantee safe from simple and long history and PSO(Particle Swarm Optimization) that sort of metaheuristic optimization that need to accuracy and fast PID parameter tuning.

• Annals of Clinical Neurophysiology
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• v.6 no.1
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• pp.39-42
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• 2004

A 20-year-old man with bilateral medial medullary infarction showed transition of bowtie and upbeat nystagmus into hemi-seesaw nystagmus. Follow-up MRI revealed near complete resolution of the right medullary lesion. This transition of nystagmus suggests that the upbeat nystagmus was generated by bilateral lesions in the ascending pathways from both anterior semicircular canals (SCC), and that the hemi-seesaw nystagmus was caused by damage to the pathway from the left anterior SCC.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.853-858
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• 2007

In this paper, a seesaw system composed with a moving cart on the rail and seesaw frame is made to demonstrate the effectiveness of the control theory. The control aim is to maintain an equilibrium of seesaw frame in spite of various initial conditions and an allowable disturbance. To solve this control problem, a PI-type state feedback controller using reduced-order observer is implemented and applied to the seesaw system. The reduced-order observer can be used to estimate the state variables in the case of the limit of sensor number or the constraint on setting sensors and the cost. A series of simulation are carried out to verify the effectiveness of the control system.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.116-120
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• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.706-708
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• 1999

In this study, a seesaw system is used as an example to demonstrate effectiveness of the control theory. This problem which keeps a seesaw's balance is corresponded to one of regulating problems. In this regard, a controller is designed by LQ techniques and an observer is implemented and applied to estimate states which cannot be actually measured in this system. And the genetic algorithm is utilized to systematically choose weighting factors in the given cost function. The performance of the controller is verified through the experiment results.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.873-878
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• 2000

Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.