• Journal of Korea Technology Innovation Society
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• v.3 no.2
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• pp.78-93
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• 2000

Since computerized numerical controller(CNC) emerged as a result of the fusion of the electronics technology and the mechanical technology, there has been continuous evolution of CNC technology in the mechatronics industry. The industry is recently developing a new control system based on the fusion of personal computer(PC) and CNC. Upgraded PC has now integrated into CNC, making various machines possible to exchange data, software and hardware, and to greatly improve man-machine interface. The fusion of PC and CNC can form a new paradigm in technological innovation of not only control system but also whole machinery industry in near the future. Korea lagged behind the developed countries in the development of open control system with the fusion of PC. Turbotek, Hyundai Motor and Daewoo are leading companies, but their commercial possibility seems to be low because domestic market is too small to reap a commercial benefit. Nevertheless, the development of the system is an essential step for Korea to embark on a future technological paradigm of the machinery industry. The government needs to play some role for the development, for instance, government R&D projects, institutional building and training of related technicians.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.257-264
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• 2014

Through MCU model, Radio Frequency communication is completed using universal asynchronous receiver and transmitter. The communicatin with PC and MCU is completed using RS-232 cable. At first interconnected communication with PC and MCU is necessary for RF communication because tha UART is based technique for RF communication. Program imbeded in microcontroller unit is ran during RF signal is transmitted to other RF module. Data connected with PC and MCU is transmitted between PC and MCU during PC and MCU is connected.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.160.4-160
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• 2001

Many physical systems today are modeled by interacting continuous and discrete states that influence the dynamic behavior. Hybrid system models, suitable for describing the essential dynamics of a fairly large class of physical systems in control engineering applications, contain both continuous dynamics and discrete dynamics. We discuss the design of efficient hybrid controllers for the platoon maneuvers on an AHS. For the modeling of a hybrid system including the merge and split operations, we introduce the safety distance policy for the merge and split operations. Then, the platoon system will be modeled by a hybrid system. In addition, the hybrid controller for the proposed merge and split operation models will be presented. Finally, we will demonstrate our scenarios ...

• Smart Structures and Systems
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• v.4 no.4
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• pp.407-428
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• 2008

The nonlinear mechanics of cable vibration is caught either by analytical or numerical models. Nevertheless, the choice of the most appropriate method, in consideration of the problem under study, is not straightforward. A feedback control policy might even enhance the complexity of the system. Thus, in order to design a suitable controller, different approaches are here adopted. Devices mounted transversely to the cable in the two directions, close to one of its ends, supply the feedback control action based on the observation of the response in a few points. The low order terms of the control law are, at first, analyzed in the framework of linear models. Explicit analytic solutions are derived for this purpose. The effectiveness of high order terms in the control law is then explored by means of a finite element model(FEM), which accounts for high order harmonics. A suitably dimensional analytical Galerkin model is finally derived, to investigate the effectiveness of the proposed control strategy, when applied to a physical model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.67-72
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• 2011

Recently, photovoltaic generator system is widely extended by energy policy of the government. Add to this, for high efficiency of power generation per natural light unit area is needed to sun tracking system. And it is needed to condensed light generator for reducer of equipment expense. As method of solving this problem, this paper is developed multi-flat reflector sun tracking system for sun photocell maximum power generation. The system is consisted of multi-flat reflector and two axes machinery and sun location perceiver and AVR controller. GaAs 3J cell generated 6.75 times power more than silicon cell by times condensing light system. As a result, condensing light system of multi-flat reflector generated maximum power and showed reducing costs to photovoltaic generator.

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.535-549
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• 2023

Deep extreme learning machine (DELM) and multi-verse optimization algorithms (MVO) are hybridized for designing an optimal and adaptive control framework for uncertain buildings. In this approach, first, a robust model predictive control (RMPC) scheme is developed to handle the problem uncertainty. The optimality and adaptivity of the proposed controller are provided by the optimal determination of the tunning weights of the linear programming (LP) cost function for clustered external loads using the MVO. The final control policy is achieved by collecting the clustered data and training them by DELM. The efficiency of the introduced control scheme is demonstrated by the numerical simulation of a ten-story benchmark building subjected to earthquake excitations. The results represent the capability of the proposed framework compared to robust MPC (RMPC), conventional MPC (CMPC), and conventional DELM algorithms in structural motion control.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.620-626
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• 2004

For general nonlinear processes, it is difficult to control with a linear model-based control method and nonlinear controls are considered. Among the numerous approaches suggested, the most rigorous approach is to use dynamic optimization. Many general engineering problems like control, scheduling, planning etc. are expressed by functional optimization problem and most of them can be changed into dynamic programming (DP) problems. However the DP problems are used in just few cases because as the size of the problem grows, the dynamic programming approach is suffered from the burden of calculation which is called as 'curse of dimensionality'. In order to avoid this problem, the Neuro-Dynamic Programming (NDP) approach is proposed by Bertsekas and Tsitsiklis (1996). To get the solution of seriously nonlinear process control, the interest in NDP approach is enlarged and NDP algorithm is applied to diverse areas such as retailing, finance, inventory management, communication networks, etc. and it has been extended to chemical engineering parts. In the NDP approach, we select the optimal control input policy to minimize the value of cost which is calculated by the sum of current stage cost and future stages cost starting from the next state. The cost value is related with a weight square sum of error and input movement. During the calculation of optimal input policy, if the approximate cost function by using simulation data is utilized with Bellman iteration, the burden of calculation can be relieved and the curse of dimensionality problem of DP can be overcome. It is very important issue how to construct the cost-to-go function which has a good approximate performance. The neural network is one of the eager learning methods and it works as a global approximator to cost-to-go function. In this algorithm, the training of neural network is important and difficult part, and it gives significant effect on the performance of control. To avoid the difficulty in neural network training, the lazy learning method like k-nearest neighbor method can be exploited. The training is unnecessary for this method but requires more computation time and greater data storage. The pH neutralization process has long been taken as a representative benchmark problem of nonlin ar chemical process control due to its nonlinearity and time-varying nature. In this study, the NDP algorithm was applied to pH neutralization process. At first, the pH neutralization process control to use NDP algorithm was performed through simulations with various approximators. The global and local approximators are used for NDP calculation. After that, the verification of NDP in real system was made by pH neutralization experiment. The control results by NDP algorithm was compared with those by the PI controller which is traditionally used, in both simulations and experiments. From the comparison of results, the control by NDP algorithm showed faster and better control performance than PI controller. In addition to that, the control by NDP algorithm showed the good results when it applied to the cases with disturbances and multiple set point changes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.767-779
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• 2013

A field of privacy protection lacks statistical information about the current status, compared to other fields. On top of that, since it has not been classified as a concrete separate field, the related survey is only conducted as a part of such concrete areas. Furthermore, this trend of being regarded as a part of fields such as informatization, information protection and law will continue in the near future. In this paper, a novel and practical way for collecting and storing a big amout of data from 110,000 privacy policies by data controller is proposed and the real analysis results is also shown. The proposed method can save time and cost compared with the traditional survey-based method while maintaining or even advancing the accuracy of results and speediness of process. The collected big personal data can be used to set up various kinds of statistical models and they will play an important role as a breakthrough of observing the present status of privacy information protection policy. The big data concept is incorporated into the privacy protection and we can observe the method and some results throughout the paper.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.1
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• pp.31-38
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• 2012

Next generation cellular applications and smart phone usage generate very heavy wireless data traffic. It becomes ineluctable for mobile network operators to have multiple core network entities such as Serving Gateway and Packet Data Network Gateway in 4G-LTE to share this high traffic generated. A typical configuration consists of multiple serving gateways behind a load-balancer which would determine which serving gateway would service a end-users'request. Such hardware is expensive, has a rigid policy set, and is a single point of failure. Another perspective of today's increasingly high data traffic is that besides it is being widely accepted that the high bandwidth L TE provides is creating bottlenecks for service providers by the increasing user bandwidth demands without creating any corresponding revenue improvements, a hidden problem that is also passively advancing on the newly emerging 4G-LTE that may need more immediate attention is the network signaling traffic, also known as the control-plane traffic that is generated by the applications developed for smartphones and tablets. With this as starting point, in this paper, we propose a solution, by a new approach considering OpenFlow switch connected to a controller, which gains flexibility in policy, costs less, and has the potential to be more robust to failure with future generations of switches. This also solves the problem of scaling the control-plane traffic that is imperative to preserve revenue and ensure customer satisfaction. Thus, with the proposed architecture with OpenFlow, mobile network operators could manipulate the traffic generated by the control-plane signaling separated from the data-plane, besides also reducing the cost in installing multiple core-network entities.

• Convergence Security Journal
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• v.20 no.5
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• pp.3-10
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• 2020

Recently, the Internet and networks are regarded as essential infrastructures that constitute society, and security threats have been constantly increased. However, the network switch that actually transmits packets in the network can cope with security threats only through firewall or network access control based on fixed rules, so the effective defense for the security threats is extremely limited in the network itself and not actively responding as well. In this paper, we propose an in-network security framework using the high-level data plane programming language, P4 (Programming Protocol-independent Packet Processor), to deal with DDoS attacks and IP spoofing attacks at the network level by monitoring all flows in the network in real time and processing specific security attack packets at the P4 switch. In addition, by allowing the P4 switch to apply the network user's or administrator's policy through the SDN (Software-Defined Network) controller, various security requirements in the network application environment can be reflected.