• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.927-932
• /
• 2006

A simulation and experimental study for energy flow dynamics of floor radiant heating system were performed. The study was done under both environmental chamber and a house with several rooms. The unsteady energy analysis method using equivalent R-C circuit and radiation heat transfer analysis of enclosure analysis method with simple structured rooms were used for computer simulation. Also, first order dynamics with time delay in analyzing the return water was considered. The results of temperature changes of the simulation study are good fit with the ones of experimental one.

• Transactions on Control, Automation and Systems Engineering
• /
• v.3 no.2
• /
• pp.124-132
• /
• 2001

Autonomous of welding process in shipyard is ultimately necessary., since welding site is spatially enclosed by floors and girders, and therefore welding operators are exposed to hostile working conditions. To solve this problem, a welding robot that can navigate autonomously within the enclosure needs to be developed. To achieve the welding ra나, the robotic welding systems needs a sensor system for the recognition of the working environments and the weld seam tracking, and a specially designed environment recognition strategy. In this paper, a three-dimensional laser vision system is developed based on the optical triangulation technology in order to provide robots with work environmental map. At the same time a strategy for environment recognition for welding mobile robot is proposed in order to recognize the work environment efficiently. The design of the sensor system, the algorithm for sensing the structured environment, and the recognition strategy and tactics for sensing the work environment are described and dis-cussed in detail.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.556-561
• /
• 2000

Comprehensive numerical computations are made of side-heated squire cavity which is exposed to time dependent external mechanical forcing. Numerical solutions are acquires to the governing two-dimensional Navier-Stokes equations for a Boussinesq fluid. Time dependent heat transfer characteristics of interior fluid are analyzed to illustrate resonance phenomenon. When system is exposed to pure sinusoidal mechanical forcing, the numerical results disclose that the basic mechanism of resonance of mechanical forcing is same as that of thermal forcing of Ref. [3, 9]. In comparatively small amplitude of mechanical forcing, thermal characteristics of the system are similar to basic system(${\varepsilon}=0$).

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1068-1074
• /
• 2010

In high speed railway, event recorder is essential system for analyzing the cause of train accident. It stores train operation sent by train control system in safe memory unit. Crash protected memory, the safe memory unit for event recorder, keeps the stored contents from severe environment. For crash protected memory, we have designed the architecture of concrete enclosure and controller board. Proposed system provides large volume of memory capacity and fault tolerance architecture. For checking the characteristics of proposed crash protected memory specification, the simulation is executed. Simulation results shows the designed crash protected memory meets all requirements.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.973-978
• /
• 2009

In this study, the thermal environment characteristics of On-Off control and thermal difference proportional control method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on two control methods, conventional on-off control and temperature error based time control(T.E.B.T.C.) method, are performed to compare thermal heating control performances, respectively.

• Journal of KSNVE
• /
• v.6 no.2
• /
• pp.205-214
• /
• 1996

Active noise control(ANC) requires the full capability of a modern digital signal processing module. This paper describes the digital signal processing unit which is designed for ANC of noise fields in passenger car. System hardware is designed to allow software controlled versatility as well as fully qutomatic operation. The developed system is provided with the ability to be self-operated except the case of upload/download of data and program between the personal computer and the system memory. Experimental results are presented to demonstrate ANC performance of noise fields in lightly damped enclosure and passenger car.

• Ocean Systems Engineering
• /
• v.3 no.1
• /
• pp.71-77
• /
• 2013

The effective tracking area of ultra short baseline (USBL) systems strongly relates to the safety of autonomous underwater vehicles (AUVs). This problem has not been studied previously. A method for determining the effective tracking area using acoustic theory is proposed. Ray acoustic equations are used to draw rays which ascertain the effective space. The sonar equation is established in order to discover the available range of the USBL system and the background noise level using sonar characteristics. The available range defines a hemisphere like enclosure. The overlap of the effective space with the hemisphere is the effective area for USBL systems tracking AUVs. Lake and sea trials show the proposed method's validity.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1887-1891
• /
• 2008

In this paper, we dealt with a partial discharge (PD) measurement method that has been accepted as an effective and non-destructive technique to estimate insulation performance of low-voltage induction motors. The PD measurement system consists of a coupling network, a low noise amplifier, and associated electronics. A shielded box was used to reduce environmental noise. Frequency characteristic of the coupling network was estimated by a sinusoidal signal input, and the low cut-off frequency of the coupling network was 1 MHz (-3 dB). Also, we carried out a calibration test for the PD measurement system. Sensitivity of the system was of 84 m$V_{max}$/pC between stator winding and enclosure. In application test on a low-voltage three phase induction motor (5 HP), we could detect 88 pC at AC 800 $V_{max}$.

• Proceedings of the SAREK Conference
• /
• 2008.11a
• /
• pp.381-386
• /
• 2008

In this study, the energy characteristic of automatic thermostatic valves according to each heating method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on heating method, valve's control method, outdoor air condition, supply heating water temperature, supply flow rate are performed to compare energy characteristic, respectively.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.52-57
• /
• 2007

The control characteristics for radiant panel heating system with automatic thermostatic valves were researched by computer simulation and experiment. The unsteady energy analysis using equivalent R-C circuit method and radiation heat transfer analysis of enclosure analysis method with simple structured rooms was performed. The results of flow rate changes of the simulation study are good fit with the ones of experimental one.