• Journal of the Korean Society for Aviation and Aeronautics
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• v.3 no.1
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• pp.37-47
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• 1995

It is very important to determine the performance and operating envelope of engine for aircraft's flight. The basic performance is provided by manufacturer, but installed engine's operating envelop is only determined by flight test. First, this study was measured cylinder head temperature(CHT), exhaust gas temperature(EGT) and oil temperature. At pre-determined altitude and power rate, these temperatures were measured by change of mixture ratio and mixture ratio condition for economic operation and max. power were found. And secondly, with the measured temperatures, possible positions of mixture lever were determined by flight test for stable flight Chang-91 and Lycoming IO-360-A series four cylinders engine with 200 hp was used for this study.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.567-571
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• 1989

This paper describes the improvement of thermal power plant turbine control system by analyzing nonlinear characteristics. The turbine control depends on the frequency variation and boiler condition. The nonlinearity of turbine control is the result of governor/valve properties, steam condition and boiler thermal unbalance. Nonlinear analysis is divided into two; main steam valve position - turbine output anal governor response. Of course, every analysis must be done on considering plant operating condition. In this paper, after analyzing turbine control nonlinearity by numerical method and actual results, the sensitive operating load which corresponds to frequency is proposed, on guarranteed boiler stability. This idea is implemented at Pyung Tack thermal power plant, and the practical results are showed.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.349-351
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• 2007

A concept of the semi-autonomous tele-weeding-system which performs weeding tasks through co-operation of human and machine intelligence is proposed. The tele-weeding system consists of weeding robot, communication networks and operating server. The images of plants taken by the weeding robot are transferred through the communication networks to the human operator. Positions of the weeds are indicated at the operating host by the operator and transferred back to the weeding robot. Such position informations are converted to the world space and the weeding is done based on the robot intelligence. Feasibility of such concept has been tested through development of a laboratory model of the system.

• Journal of Mechanical Science and Technology
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• v.18 no.3
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• pp.370-378
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• 2004

An autonomous pipeline inspection gauge system has been developed for determining position, orientation, curvature, and deformations such as dents and wrinkles of operating pipelines by Korea Gas Company and Seoul National University. The most important part of several subsystems is the Strapdown Inertial Measurement Unit (SIMU), which is integrated with velocity and distance sensors, weld detection system, and digital recording device. The Geometry Pipeline Inspection Gauge (GeoPIG) is designed to operate continuously and autonomously for a week or longer in operating gas pipelines. In this paper, the design concepts, system integration, and data processing/analysis method for the PIG will be presented. Results from the recent experiment for a 58 kilometer gas pipeline will be discussed.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.297-303
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• 2002

We have developed an on-line ultrasonic detector to monitor partial discharge in an operating transformer. The ultrasonic sensor has 150[KHz] resonance frequency and contains a pre-amplifier with 60[㏈] gain. The on-line ultrasonic detector has 50~300[KHz] frequency band-pass filter to remove electrical and mechanical noises from the transformer. This detector has an ultrasonic signal discrimination algorithm which discriminates ultrasonic signals due to partial discharge in a transformer. A moving average method of ultrasonic signal number was employed to effectively monitor the increasing trend of the partial discharge. This paper describes an experience of partial discharge detection in a 154[㎸] operating transformer using an ultrasonic detector. With regards to gas analysis in oil, C2H2 gas was produced with a warning level in this transformer We detected ultrasonic signals on the transformer steel wall, and estimated the position of partial discharge. With further inspection, we found carbonized marks due to partial discharge on the supporting bolt which fastens the windings.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.449-451
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• 2001

This study presents a study on modified algorithm to operating train simulation of AT feeding systems. In this study equivalent impedance is constructed by $Z_c,\;Z_r,\;Z_f,\;Z_{cr},\;Z_{rf},\;Z_{fc}$. The train current flows through the all auto-transformer corresponding to track impedance. To calculate train voltage from analyzing the railway systems, the algorithm is based on the K. C. L, K. V. L, superposition and circuit separation method. Multi-train's voltages are determined by calculating the catenary voltage at each train's position and adding up these train's voltage drop. Case studies use a field operational data, show that the proposed method is easily applied.

• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.147-161
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• 1996

The development of universal CCD camera control software for all BOAO CCD camera systems is proposed. The new software, running under Sun SPARCstation and motif based X window system with SunOS 4.1.3 operating system, replaces existing control software based on NeXTstation color and NeXTstep 2.1 operating system which is no more produced now. Several new features of the new software is introduced, some of which are 1) the image contrast is enhanced by color manipulation and display, 2) image zooming and trimming, 3) any size of image can be displayed in the scrolled window, and 4) the offset between telescope pointing position and CCD center is easily calculated by alt-azi map. Along with the above new features, the new software has advantages including ease of maintenance and upgrading and elimination of risk caused by hardware damage. Since September 1, the software beta version is being used by observers and there is not seen severe problem regarding the software itself, but several requests to equip more features to the software will be mirrored to future release.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.4
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• pp.655-669
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• 2015

The Overall Motion Sickness Incidence is applied to the hull form optimization of a wave piercing high-speed catamaran vessel. Parametric hull modelling is applied to generate two families of derived hull forms, the former varying the prismatic coefficient and the position of longitudinal centre of buoyancy, the latter instead the demi-hull separation. Several heading angles are analysed in a seaway, considering all combinations of significant wave height and zero-crossing period under two operating scenarios. The optimum hull is generated and vertical accelerations at some critical points on main deck are compared with the parent ones. Finally a comparative analysis with the results obtained for a similarly sized monohull passenger ship is carried out, in order to quantify, by the OMSI, the relative goodness in terms of wellness onboard of monohulls and catamarans, as a function of sea states and operating scenarios.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.226-228
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• 2007

SRM drive systems are designed to meet operating standards such as low cost, constant torque independent of rotor position, a desired operating speed range, high efficiency, and high performance. In applications using small motors, low cost and high performance with self-starting capabilities are highly desired. This paper discusses a novel two phase SRM (TPSRM) that has high performance characteristics with self-starting capability, low manufacturing cost with a two phase inverter and simple magnetic structure, and high efficiency. The principle of operation, analysis, and simulation for design are presented. The machine design is verified using finite element analysis (FEA) software. Analysis and simulation results are given to validate the TPSRM design.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.852-860
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• 2010

An environment in which the software is operated become more complex and changed dynamically. Such software requires the ability to adapt in accordance with operating environments, by monitoring the changes of user requirements and operating environments. Especially, the mobile device used in military operation requires more dynamical adaptation than the mobile device in normal environment. In this paper, we propose MOSAIC architecture based on Self-Adaptive Software suitable for military mobile device and verify the results. The proposed architecture consists of context manager, evaluation manager and adaptation manager. We simulate the MOSAIC architecture by modelling PRE(Position Reporting Equipment) used in the army and verify four types of operational mode and dynamical reconfiguration of user interface.