• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.386-394
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• 2011

This paper is concerned with the application of the vision control scheme for robot's point placement task in discontinuous trajectory caused by obstacle. The proposed vision control scheme consists of four models, which are the robot's kinematic model, vision system model, 6-parameters estimation model, and robot's joint angles estimation model. For this study, the discontinuous trajectory by obstacle is divided into two obstacle regions. Each obstacle region consists of 3 cases, according to the variation of number of cameras that can not acquire the vision data. Then, the effects of number of cameras on the proposed robot's vision control scheme are investigated in each obstacle region. Finally, the practicality of the proposed robot's vision control scheme is demonstrated experimentally by performing the robot's point placement task in discontinuous trajectory by obstacle.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.54-62
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• 1993

Generally, the main difficulty in the composition of tank-level control system may be in the point that plant parameters are severely varied according to the change of operating point. In order to cope with this difficulty, in this paper, an adaptive control is employed using model-following technique based on the optimal control law. Through the simulations and experiments the following results were observed. 1) The steady-state error was not found under the parameter variations caused by the change of operating point. 2) In spite of the change of operating point, the corresponding gains which were stored in the computer were found to be automatically updated so that the controller could have the adaptive ability. And also, the control specifications in view of transient response were found to be satisfied.

• KIEE International Transactions on Power Engineering
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• v.5A no.2
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• pp.152-158
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• 2005

This paper describes a reactive optimal power flow incorporating margin enhancement constraints. Margin sensitivity at a steady-state voltage instability point is calculated using invariant space parametric sensitivity, and it can provide valuable information for selection of effective control parameters. However, the weakest buses in neighboring regions have high margin sensitivities within a certain range. Hence, the control determination using only the sensitivity information might cause violation of operational limits of the base operating point, at which the control is applied to enhance voltage stability margin in the direction of parameter increase. This paper applies an interior point method (IPM) to solve the optimal power flow formulation with the margin enhancement constraints, and shunt capacitances are mainly considered as control variables. In addition, nonlinearity of margin enhancement with respect to control of shunt capacitance is considered for speed-up control determination in the numerical example using the IEEE 118-bus test system.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.638-643
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• 2004

Middleware enables different networking devices and protocols to inter-operate in ubiquitous home network environments. The UPnP(Universal Plug and Play) middleware, which runs on a PC and is based on the IPv4 protocol, has attracted much interest in the field of home network research since it has versatility The UPnP, however, cannot be easily accessed via the public Internet since the UPnP devices that provide services and the Control Points that control the devices are configured with non-routable local private or Auto IP networks. The critical question is how to access UPnP network via the public Internet. The purpose of this paper is to deal with the non-routability problem in local private and Auto IP networks by improving the conventional Control Point used in UPnP middleware-based home networks. For this purpose, this paper proposes an improved Control Point for accessing and controlling the home network from remote sites via the public Internet, by adding a web server to the conventional Control Point. The improved Control Point is implemented in an embedded GNU/Linux system running on an ARM9 platform. Also this paper implements the security of the home network system based on the UPnP (Universal Plug and Play), adding VPN (Virtual Private Network) router that uses the IPsec to the home network system which is consisted of the ARM9 and the Embedded Linux.

• Journal of Mechanical Science and Technology
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• v.16 no.8
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• pp.1079-1088
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• 2002

Motivated by the dynamic output feedback passification results, point-to-point control laws for an elastic joint robot are presented when only the position measurements are available. The proposed method makes a parallel connection of the robot system and an input-dimensional linear system which obtains the effect of the desired differentiators. It is shown that the closed-loop nonlinear robot system can be rendered output strictly passive and the regulation of the system is achieved in the end. Robustness analysis is also given with regard to uncertainties on the robot parameters. Performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.75-80
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• 2003

Most of the control point surveying use a triangulation point and a bench mark with Total Station and Level. nowadays, the research is being accomplished for practical use of GPS. but In this study the optimum time and the optimum occupation time are analyzed, so as to examine possibility of the control point surveying that use GPS continuous station data of National Geography Institute. Also, The efficient surveying methods that compare the result of data that processed using broadcast ephemeris with the result of data that processed using precise ephemeris. As a result of that, Error feature analysis of the control point surveying in connection with GPS continuous observation will provide us estimation of errors and efficient topography information acquisition

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.789-797
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• 2003

In the procedure of the hydraulic control system design, a linearized approximate equation described by the first order terms of Taylor series has been widely used. Such a linearized equation is effective just near the operating point, However, pressure and flowrate in actual hydraulic systems are usually not confined near an operating point. This study suggests a new linearized flow equation for a servovalve as a modified form of the conventional linearized flow equation. Subsequently, a procedure to determine effective operating point for the new linearized equation is proposed. From the evaluations of time responses and frequency responses obtained from simulations for a hydraulic control system, the effectiveness of the new linearized equation and the procedure to determine effective operating point is confirmed.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.1-6
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• 2010

Purpose: This study investigated the effects of visual feedback during abdominal hollowing (AH) in four point kneeling position, using real-time ultrasound imaging through measurement of the changes in the thickness of transversus abdominis (TrA), internal abdominal oblique (IO), and external abdominal oblique (EO). Methods: The subjects of this study were 32 healthy males who were divided intothe experimental group of 16 subjects and the control group of 16 subjects. The real-time ultrasound feedback was applied to the experimental group while they were educated on the AH exercise in four point kneeling whereas only general education and training were given to the control group. After the training, the changes in the thickness of abdominal muscles during AH in four point kneeling were compared between the experimental group and the control group. Results: The differences of the changes in the thickness of TrA and EO between the two groups were statistically significant. Conclusion: The experimental group experienced a higher increase in the thickness of TrA than the control group while the thickness of IO and EO of the experimental.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.2
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• pp.157-174
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• 2012

This study tries to describe personal name access point control ontology for the American novelist Mark Twain using RDF/OWL axiom to control access point based on the ontology. The Axiom used in this study are disjoint with class, domain and range, property cardinality, inverse functional property, individual and literal data property. As a result, in the ontology environment we can accept various access points as equal access points exclusive of authority heading and heading concept. It can successfully describe Mark Twain's personal name access point control ontology and display using the OntoGraf.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.720-722
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• 2015

In this paper, we propose a new type of integrated wireless control system using a cloud-based AP Controller. With this system, network administrator can control wireless network in head office and branch hierarchically. In head office, they have an AP Controller Manager, it can control all Access Points, Access point Controllers in their networks. In addition, if we need to install new Access point Controller because of the increasing number of Access Point, the process of making virtual Access point Controller can be automated. This paper presents an architecture of the integrated wireless control system, as well as describes its components and protocols.