• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.506-506
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• 2000

To improve control performance of a non-linear system, many other researches have used the sliding mode control algorithm. The sliding mode controller is known to be robust against nonlinear and unmodeled dynamic terms. However. this algorithm raises the inherent chattering caused by excessive switching inputs around the sliding surface. Therefore, in order to solve the chattering problem and improve control performance, this study has developed the sliding mode controller with a perturbation estimator using the observer-based fuzzy adaptive network generates the control input for compensating unmodeled dynamics terms and disturbance. And, the weighting parameters of the fuzzy adaptive network are updated on-line by adaptive law in order to force the estimation errors to converge to zero. Therefore, the combination of sliding mode control and fuzzy adaptive network gives rise to the robust and intelligent routine. For evaluating control performance of the proposed approach. tracking control simulation is carried out for the hydraulic motion simulator which is a 6-degree of freedom parallel manipulator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.944-957
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• 2007

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstopping control method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.413-417
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• 1997

Distributed piezoelectric sensor and actuator have been designed for efficient vibration control of a cantilevered beam. Both PZT and PVDF are used in this study, the former as an actuator and the latter as a sensor for our integrated structure. For the PZT actuator, the position and size have been optimized. Optimal electrode shape of the PVDF sensor has been determined. For multi-mode vibration control, we have used two PZT actuators and a PVDF sensor. Electrode shading of PVDF is more powerful for modal force adjustment than the sizing and positioning of PZT. Finite element method is used to model the structure that includes the PZT actuator and the PVDF sensor. By deciding on or off of each PZT segment, the length and the location of the PZT actuator are optimize. Considering both of the host structure and the optimized actuators, it is designed that the active electrode width of PVDF sensor along the span of the beam. Actuator design is based on the criterion of minimizing the system energy in the control modes under a given initial condition. Sensor is designed to minimize the observation spill-over. Modal control forces for the residual(uncontrolled) modes have been minimized during the sensor design. Genetic algorithm, which is suitable for this kind of discrete problems, has been utilized for optimization. Discrete LQG control law has been applied to the integrated structure for real time vibration control. Performance of the sensor, the actuator, and the integrated smart structure has been demonstrated by experiments.

• The Journal of Korea Robotics Society
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• v.5 no.4
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• pp.349-358
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• 2010

We presents a dynamic modeling of 4-wheel 2-DOF. WMR. The classic dynamic model utilizes a greatly simplified wheel motion representation and using of a simplified dynamic model confronts with a problem for accurate position control of wheeled mobile robot. In this paper, we treats the dynamic model for describes relationship between the wheel actuator force/torque and WMR motion through the use of Newton's equilibrium laws. To calculate the WMR position in real time, we introduced the Dead-Reckoning algorithms and the simulation result show that the proposed dynamic model is useful. We can be easily extend the proposed WMR model to mobile robot of similar type and this type of methodology is useful to analyze, design and control any kinds of rolling robots.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.146-167
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• 2001

Korea and China are two opposite countries located aside Yellow Sea and co-utilize the East China Sea. The two countries are close together from geological point of view, however, the competitive development of resources was more emphasized than the cooperative development of resources between the two countries because the special policy relationship. Additionally, after the communist government of China was founded in 1949, the political conception between the two countries was quite different. Therefore the establishment of appropriate international fisheries co-operation was impossible, and the international management problems of fisheries resources in Yellow Sea and East China Sea were let alone. UN convention on the Law of the Sea came to force in 1994, Korea and China adopted the exclusive economic zone system in 1996. On the other hand, Fisheries Law in Korea was enacted in 1953 in order to management of fisheries resources, and also China was enacted fisheries law in 1986. The two countries control the fisheries effort through fisheries license system, meanwhile through prohibition fishing area, prohibition fishing period, limitation of net size, and limitation of body length to conserve and manage the fisheries resource. The serious management methods of resource management in the two countries are similar such as the creation of promptly decreased species and those species that have commercial value, discharge of fish seedling stock, settlement of artificial reef and clean of fishing ground. Therefore, the two countries should consider not only the improvement of formal law system, but also how to recover the fisheries resources in circumference water zone and how to improve the efficiency of fisheries resource management. Specially the settlement and management of artificial reef should be chosen in the area that have the highest benefit to two countries, and should establish the common management system of discharge of fish seedling stock. And the two countries should adopt the same criteria through technical management and limitation of net size, limitation of body length, and prohibition area of special fisheries to ensure the highest fisheries benefit of fisherman in the two countries and the highest efficiency of fisheries resource management.

• Journal of Environmental Policy
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• v.13 no.4
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• pp.161-190
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• 2014

The Nagoya Protocol will enter into force on 12 October, 2014 during the period of UNCBD COP12 which will be held in Pyeongchang, Korea. In this circumstance, it is essential to analyze other countries' legislations and find various related issues. Based on that analysis, Korea can set its course for related policies and also improve its own legislations. EU and China were selected as comparison countries since EU is one of the leading countries trying to establish an international environmental law system and China is regarded as a model country representing LMMC (Like-Minded Mega-diverse Countries) in the world. Based on this study, it is highly recommended for Korea to assert the need for dispute resolution between private and government parties and also trilateral co-management of trans-boundary genetic resources and related traditional knowledge among Korea, China and Japan. In addition, Korea also needs to improve its legislation towards integrating the management and control of genetic resources.

• Korean Security Journal
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• no.50
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• pp.307-337
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• 2017

The freedom of assembly is the fundamental freedoms guaranteed by the Constitution. However, as far as our reality is concerned, the freedom of assembly is guaranteed only when it is under the control of the police, and otherwise it is perceived as an object to be suppressed. Police say even that they will not tolerate even a small illegal law while referring to the "broken window theory". Therefore, regardless of the peaceful nature of the rally, it is too obsessed with 'compliance'. This attitude is causing the citizens who participated in the assembly to be put to the object to be suppressed. This paper analyzes the requirements and current status of police force, focusing on the vehicle-wall-blocking and water cannon as a means of using the police force, which is a recent problem, and suggests ways to improve it. First of all, the installation of the wall cuts off the essential communication function of the assembly by separating the meeting place from the object of protest. Thus, despite the warning for prevention in the face of illegal acts, other than installing a barrier, it should be allowed only in the 'urgent case where there is a risk of causing damage to the life, body or property of the person'. Without this urgency, the vehicle-wall-blocking should not be allowed to be proactive as well as preventive. Secondly, the water cannon is a police force that is likely to harm people's life and body. Therefore, aiming shots, which could pose a significant risk to the human body, should in principle be prohibited. However, considering its risk, it should be supplementary used only when there is no other alternative, only when the direct risk to the legal interest of the other person or the order of public well-being is 'obvious'. In addition, as for the use standard of such a thing, it is necessary to be specified by law.

• Korean Security Journal
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• no.26
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• pp.59-87
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• 2011

Security Business Act of Korea is leaning toward the aspect of regulation, while it provides few provisions about vesting the authority, which causes problems such as legal loopholes to be raised in regard to the rules about authorizing the private security personnel to perform security affairs properly and defining the limit of power. So, it should be done to interpret the law in order to draw the legal basis of empowering as well as to set limits of the authority of security main agent, and Article 7, Section 1, of Security Business Act is the very provision that involves the legal basis. In the scope of 'Management Power', the statutory authority in the first clause of Article 7 of Security Business Act, the security personnel can use force for self-defense, defense of others and property, and prevention of crimes. In addition, the powers of interrogation, access control, and eviction notice are involved in its scope. The private security personnel as the occupation assistant can take precautions and if the infringement on the benefit and protection of the law is imminent or done, he or she can use force within the limits of the passive resistance and the means of defiance on the basis of 'Management Power'. The private security personnel, however, can exercise the force only if the necessary conditions of legal defense, emergency evacuation, and legitimate act of criminal law are fulfilled.

• Journal of Preventive Medicine and Public Health
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• v.47 no.3
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• pp.129-135
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• 2014

Tobacco use is the most important preventable risk factor for premature death. The World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC), the first international public health treaty, came into force in 2005. This paper reviews the present status of tobacco control policies in Korea according to the WHO FCTC recommendations. In Korea, cigarette use is high among adult males (48.2% in 2010), and cigarette prices are the lowest among the Organization for Economic Cooperation and Development countries with no tax increases since 2004. Smoke-free policies have shown incremental progress since 1995, but smoking is still permitted in many indoor public places. More than 30% of non-smoking adults and adolescents are exposed to second-hand smoke. Public education on the harmful effects of tobacco is currently insufficient and the current policies have not been adequately evaluated. There is no comprehensive ban on tobacco advertising, promotion, or sponsorship in Korea. Cigarette packages have text health warnings on only 30% of the main packaging area, and misleading terms such as "mild" and "light" are permitted. There are nationwide smoking cessation clinics and a Quitline service, but cessation services are not covered by public insurance schemes and there are no national treatment guidelines. The sale of tobacco to minors is prohibited by law, but is poorly enforced. The socioeconomic inequality of smoking prevalence has widened, although the government considers inequality reduction to be a national goal. The tobacco control policies in Korea have faltered recently and priority should be given to the development of comprehensive tobacco control policies.

• Smart Structures and Systems
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• v.20 no.5
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• pp.525-537
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• 2017

This paper explores different vibration control strategies for the cancellation of human-induced vibration on a structure with time-varying modal parameters. The main motivation of this study is a lively urban stress-ribbon footbridge (Pedro $G\acute{o}mez$ Bosque, Valladolid, Spain) that, after a whole-year monitoring, several natural frequencies within the band of interest (normal paring frequency range) have been tracked. The most perceptible vibration mode of the structure at approximately 1.8 Hz changes up to 20%. In order to find a solution for this real case, this paper takes the annual modal parameter estimates (approx. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the most-repeated modal properties of the aforementioned mode, b) two semi-active TMD strategies, one with an on-off control law for the TMD damping, and other with frequency and damping tuned by updating the damper force. All strategies have been carefully compared considering two structure models: a) only the aforementioned mode and b) all the other tracked modes. The results have been compared considering human-induced vibrations and have helped the authors on making a decision of the most advisable strategy to be practically implemented.