• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.137-141
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• 1999

In this paper, we developed a Windows 95 version off-line programming system which can simulate a track vehicle model in 3D graphics space. The track vehicle was adopted as an objective model. The interface between users and the off-line program system in the Windows 95's graphic user interface environment was also studied. The developing language is Microsoft visual C++. Graphic libraries, OpenGL, by Silicon Graphics, Inc. were utilized for 3D Graphics.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.194-198
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• 2000

In this paper, we developed a Windows 98 version off-line programming system which can simulate a track vehicle model in 3D graphics space. The track vehicle was adopted as an objective model. The interface between users and the off-line program system in the Windows 98' graphic user interface environment was also studied. The developing language is Microsoft Visual C++. Graphic libraries, OpenGL, by Silicon Graphics, Inc. were utilized for 3D graphics.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.305-305
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• 2000

In this paper, we developed a Windows 98 version off-line programming system which can simulate a track vehicle model in 3D graphics space. The track vehicle was adopted as an objective model. The interface between users and the off-line program system in the Windows 98's graphic user interface environment was also studied. The developing language is Microsoft Visual C++. Graphic libraries, OpenGL, by Silicon Graphics, Inc. were utilized for 3D Graphics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.894-897
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• 2004

In this paper, we address a position control scheme for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived based on Newton-Euler method and its special Jacobian matrix describing a relation between the Joint velocity and platen velocity is done. There are proposed two control schemes for positioning, which are Cartesian space controller and Joint space controller. The control performance of the Cartesian space controller is better than the Joint space controller in task space trajectory while the Joint space controller is simpler than the Cartesian space controller in controller realization.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.29-39
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• 2024

Recently, the space field has become an important element both for national economies and in national security. In the continued development of the space field, policy must play a very important role. However, many researchers who want to participate in space policy are experiencing difficulties due to the lack of a clear explanation and definition of the term 'space policy' itself. Accordingly, this paper defines 'space policy', which is further classified into 'space research and development policy', 'space economy policy', 'space law and regulation policy', 'space security policy', and 'space diplomacy policy'. The important elements of each space policy field are analyzed as well.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.187-192
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• 2009

Telecommand & telemetry control equipment is needed for the testing of the transponders during the development of satellite. This equipment must have a loopback function to perform the self testing without satellite. The fabrication of the designed system is easier and cheaper than the conventional testing system using direct modulation method. The measured results of fabricated equipment are satisfied with required specifications. A overall path loss of uplink and downlink is 47.8 dB and 42.6 dB, respectively. Also, IMD3 of uplink has measured 60.68 dBc at an output of -50 dBm.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.82-98
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• 2021

In recent years, as the number of ground subsidence has increased nationwide, the latest and usefulness of underground information for underground space development and underground safety management has become more important than ever. However, the 3D Underground Geospatial Map project, which started in 2015, has a problem with the manual-based long-term update system. This research paper overcomes these limitations and automatically updates the 3D CAD/GIS-based integrated management of underground structures that can be managed automatically from a full-cycle perspective of underground structure data management such as processing, transformation, updating, management, and visualization of 2D/3D underground structure data. If this technology is applied, it is possible to integrate processing and update management of the existing complex 3D construction logic of underground structures in one system, and it is expected that it can be used for underground space development and underground safety management as a foundation technology for automatic update of underground structures data.

• Journal of the Optical Society of Korea
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• v.20 no.3
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• pp.368-380
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• 2016

There is no doubt that adaptive optics (AO) is the most promising method to compensate wavefront disturbance in free space optics communication (FSO). In order to improve the performance of the AO system described by discrete-time linear system model with time-delay and implicit phase turbulent model, new controllers based on a Kalman filter and its extensions are proposed. Based on the standard Kalman filter, we propose a fading memory filter to deal with the ruleless strong interference; sequential and U-D filters are applied to reduce implementation complexity for the embedded controllers. Theoretical analysis and the numerical simulations show that the proposed fading memory filter can upgrade the performance for AO systems in consideration of the unforeseen strong pulse interference, and the sequential and U-D filters perform well compared with a Kalman filter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.665-671
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• 2006

In this paper, we propose and observe a system that adopts Independent-MCS (Modulation and Coding Scheme) level for each layer in the combined AMC-V-BLAST (Adaptive Modulation and Coding-Vertical-Bell-lab Layered Space-Time) system. Also, comparing with the combined system using Common-MCS level, we observe throughput performance improvement. As a result of simulation, Independent-MCS level case adapts modulation and coding scheme for maximum throughput to each channel condition in separate layer, resulting in improved throughput compared to Common-MCS level case. Especially, the results show that the combined AMC-V-BLAST system with Independent-MCS level achieves a gain of 700kbps in $7dB{\sim}9dB$ SNR (Signal-to-Noise Ratio) range.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.84-92
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• 2022

The electro-hydrostatic actuator (EHA) recently has been used in flight control fields for aircraft because of its benefits of minimizing oil leakage and weight, improving safety, and etc. while independently operating the hydraulic power source and eliminating complex hydraulic piping. The aircraft of which EHA is installed inside, has the thermal management issue of EHA, because of its limited cooling source as compared with the aircraft which installs the traditional central hydraulic system. So, the thermal analysis model which predicts the thermal characteristics of EHA, is required to resolve this thermal management issue. In this study, an oil circulation circuit inside the hydraulic power module comprised of hydraulic pump and electrical motor for EHA was applied. This is for the purpose of developing the internal rotary group of hydraulic power module, which operates under the conditions of high rotation speed and hydraulic pressure. After formulating an appropriate thermal analysis model, the thermal analysis results with oil cooled or no oil cooled hydraulic control module were compared and reviewed, for the purpose of predicting the thermal characteristics of EHA.