• Journal of the Korean Chemical Society
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• v.16 no.1
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• pp.25-32
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• 1972

The effect on the apparent viscosity of 2 wt. % Veegum suspensions of different types of electrolytes and of different electrolyte concentrations was studied. Measurements were made with a Brookfield Synchro-Lectric Viscometer, using no.3 spindle at 30 R.P.M. at $24^{\circ}C$. As electriolyte concentration increased, the apparant viscosity was observed to increase to a maximum and then to decrease. Changes in viscosity were in general agreement with predicted results based on the Hofmeister sequence and the Schulze-Hardy rule. The observed electrolyte effect on the apparent viscosity was discussed in terms of the Verwey-Overbeek theory.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.4
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• pp.39-49
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• 2006

LYNX ESM has not only ESM function but Datalink function. The LYNX boarded equipment Interface and Channel coding is needed for LYNX Datalink to support the mother ship with tactical data included threat radar analysis data of LYNX ESM, navigation data, Radar and Sonar of LYNX. The interface of loaded equipments are various protocol like as ARINC419/429, RS232, Synchro, Sync Serial. The Channel coding of Convolution-Scrambler-Interleaver-Bit Stuffing is applied for recovering the transmission data mixed with propagation errors in sea environment.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.159-162
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• 2000

This paper addresses the design and implementation problem of the mobile robot with the synchronous driving mechanism that consists of modular control systems based on the Universal Serial Bus (USB). Recently, the USB have attracted the hardware developers'interests due to its low cost, compatibility, and extenability. In particular, the USB enables us to organize the whole system in the modular manner very easily, and this property plays a very important role in shortening the developing time in implementing the target system, for example, the mobile robot system. In this paper, we implement the USB motion controller and the USB ultrasonic sensor system and verified the validity and the effectiveness of the proposed system through the real experiments including the mobile robot navigation and the environment recognition.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.273-274
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• 2008

Recently, the most wide-area blackout in North America, Canada and Europe had shown us indirectly the importance of Wide-Area Power System Protection and had influence on the direction of domestic electric power industry. After reorganization of the electric power industry in 2001, market incentives controls the power generation, transmission and distribution rather than stability of power grid, and moreover it produce bad results like inefficient facility management and too much competition. In addition, we can easily predict the massive loss of social and economic when the wide-area outage occurs by north direction load flow which is a pending problems of domestic power system and in a changed industry likes hi-tech manufacture and information technology industries. This paper introduces the development of infra systems for prevent wide-area blackout in situations of the power system operations.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.146-149
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• 2002

This paper presents collision avoidance for mobile robots equipped with synchro-drive using curvature trajectory by the obstacle type. he new real-time obstacle avoidance method presents how to create a curvature trajectory in which dynamics of a mobile robot is considered we controlled translation and rotational velocity of the mobile robot. Using these two speeds with curvature trajectory, the mobile robot navigates to target point without collision. We consider that the robot going to curvature trajectory by obstacle size towards a goal location. The collision avoidance has been implemented and tested using pioneer2-dxe mobile robot.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2457-2459
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• 2002

In this paper, we describe the way how to create a curvature trajectory where the dynamics of a mobile robot is considered. Synchro-drive motor is used in a mobile robot. And translational and rotational speeds are controlled independently. Using these two speeds, a mobile robot traces a smooth curvature trajectory that consists of circle trajectories to a target point. While trying to avoid obstacles, the robot can be goal-directed using curvature trajectory. Also, while the robot can navigate the trajectory, the maximum speed is controlled to trade off speed and safely.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.457-462
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• 2005

An empirical way of a covariance matrix which expresses the odometry uncertainty of mobile robots is proposed. This method utilizes PC-method which removes systematic errors of odometry. Once the systematic errors are removed, the odometry error can be modeled using the Gaussian probability distribution, and the parameters of the distribution can be represented by the covariance matrix. Experimental results show that the method yields $5{\%}$ and $2.3{\%}$ offset for the synchro and differential drive robots.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.39-41
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• 2005

In this paper, a study on the controller for high speed PMSM (Permanent Magnet Synchro-nous Motor) is described. PMSM can be driven over 50,000 rpm because it has no brush and commutator structure. It also has less EMI noise and easy cooling structure compare to the other motors. The controller was designed to have a capability to drive 20kw, 42,000rpm high speed motor system. A senseless vector control method was studied based on d-q conversion theory to have a high driving efficiency. The control board was designed using TMS320C33 and the performance was verified by experimental results on driving the inverter and motor system.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2464-2466
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• 2001

In this paper, a behavior-based fuzzy control of mobile robots for autonomous navigation is presented. Behaviors of mobile robots are divided into two categories: reactive behavior and purposeful behavior, which are incompatible with each other. The former is reaction performed in terms of the sensory data and the latter is action for achieving the goal. The presented method generates appropriate control inputs to the robot to trade-off between the reactive and purposeful behaviors using fuzzy inferences. The method is applied to an synchro-drive type mobile robot and shown to be useful for autonomous robot navigation by providing simulation results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.1-7
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• 2021

In this study, MIG welding was performed on extruded 6005A-T6 material, which is used in the base panel of railway vehicles. The material was considered as the experimental base material, and argon shielding gas and ER5356 and ER4043 filler metals were used as the consumable welding materials. Welding coupons were prepared under various welding conditions by using an auto-welding system that various welding conditions applied 2.5Hz and 4.5Hz the pulse frequency of SynchroPuls function of welding machine and 1.0mm and 1.5mm of root face affect the weld penetration of welding joint. The welding current and voltage were also varied for this testing. On the basis of the results obtained, optimum welding conditions are proposed.