• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.289-292
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• 2003

Digitalized multimedia contents is changing active digital contents in form passed from manufacturer directly to consumer though digital network of high speed, also face with big problem that is protection of rights to protect digital contents, to protect those and effort to active digital contents process height. Also, in situation that require change to more efficient system, the efficiency of rights document that is basic intermediate to be used in business of digital contents field is emphasized. Therefore, the design of common business model to share contents that have same purpose without depending on specific system to offer contents with another system is required. This paper designed adaptable rights business model to general digital contents, and designed and implemented rights document editing system to editable document for Right management according to designed business model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.43-48
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• 2020

Open pit mines for limestone mining require rapid development of technologies and efforts to prevent safety accidents due to rapid deterioration of the slope due to deforestation and rapid changes in the topography. Accurate three-dimensional spatial information on the terrain should be the basis for reducing environmental degradation and safe development of open pit mines. Therefore, this study constructed spatial information about open pit mine using UAV(Unmanned Aerial Vehicle) and analyzed its utility. images and 3D laser scan data were acquired using UAV, and digital surface model, digital elevation model and ortho image were generated through data processing. DSM(Digital Surface Model) and ortho image were constructed using image obtained from UAV. Trees were removed using 3D laser scan data and numerical elevation models were produced. As a result of the accuracy analysis compared with the check points, the accuracy of the digital surface model and the digital elevation model was about 11cm and 8cm, respectively. The use of three-dimensional geospatial information in the mineral resource development field will greatly contribute to effective mine management and prevention of safety accidents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.2
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• pp.262-268
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• 2019

Previous dynamic models of hysteresis motor use an extended induction machine equivalent circuit or somewhat different equivalent circuit with conventional one, which makes unsatisfiable results. In this paper, the hysteresis dynamic characteristics of the motor rotor are analyzed using the inverse Preisach model and the hysteresis motor equivalent circuit considering eddy current effect. The hysteresis loop for the rotor ring is analyzed under full-load voltage source static state. The calculated hysteresis loop is then approximated to an ellipse for simplicity of dynamic computation. The permeability and delay angle of the elliptic loop apply to the dynamic analysis model. As a result, it is possible to dynamically analyze the hysteresis motor according to the applied voltage and the rotor material. With this method, the motor speed, generated torque, load angle, rotor current as well as synchronous entry time, hunting effect can be calculated.

• Journal of Digital Contents Society
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• v.5 no.2
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• pp.151-156
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• 2004

This paper presents process model to accomplish traffic engineering in Internet. The process model consists of 4 stages. The first stage is the formulation of a control policy dominated network operation. The second stage is the observation of the network state through a set or monitoring functions. The third stage is the characterization or traffic and analysis or the network state. The final stage is the optimization of network performance. the four stages of the process model defined above are iterated.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.1
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• pp.48-65
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• 1995

This paper deals with the analysis of the unintentional radiation from the TDX-1B subscriber Board. According to the demand of digital systems and developement of high speed switching devices, electro- magnetic noise intensity and it's bandwidth occupancy in spectrum are increasing and so there is a serious possibility causing the various EMI phenomena. More accurate radiation model was established by using the Finite Difference Time Domain (FDTD) analysis, and the EMI probabilistic analysis of the digital switching system was performed. For validating the proposed model and its calculated results, on-promises test was performed and compared with the calculated results. These results may be applicable to be used for EMI model in large digital system, and prediction of EMI effect from a large digital system, and the EMI control design when designing digital system to meet inter- national EMI regulation.

• Nuclear Engineering and Technology
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• v.29 no.1
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• pp.15-24
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• 1997

The design and evaluation of a digital U-tube steam generator level controller of nuclear power plants, which uses model-based compensators to offset the inverse response behavior of water level, is described. Included is a review of steam generator level dynamics, a simulation model that replicates the effects of feedwater and steam flowrate as well as temperature on steam generator level, the design of both the compensators and the overall controller, and the results of simulation studies in which the performances of this model-based controller and existing analog ones were compared. The proposed digital steam generator level controller is stable and its use significantly improves the controllability of steam generator level.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.3
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• pp.251-259
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• 2005

A discrete time model reference adaptive control has been applied in order to compensate the nonlinear friction characteristics in a hydraulic proportional position control system. As nonlinear friction, static and coulomb friction forces are considered and modeled as dead zone and external disturbance respectively. The model reference adaptive control system consists of a cascade combination of the dead zone. external disturbance and linear dynamic block. For adaptive control experiment. the DSP(Digital Signal Processor) board has been interfaced the hydraulic proportional position control system. The experimental results show that the MRAC(Model Reference Adaptive Control) for compensation of static and coulomb friction are very effective.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1634-1637
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• 2003

Any given object on the motor-driven turntable is pictured from 8 to 72 different views with a digital camera. 3D shape reconstruction is performed with the integrated software called by Scanware from these multiple digital photographs. There are several steps such as configuration, calibration, capturing, segmentation, shape creation, texturing and merging process during the shape reconstruction process. 3D geometry data can be exported to cad data such as Autocad input file. Also 3D image model is generated from 3D geometry and texture data, and is used to advertise the model in the internet environment. Consumers can see the object realistically from wanted views by rotating or zooming in the internet browsers with Scanbull spx plug-in. The spx format allows a compact saving of 3D objects to handle or download. There are many types of scan equipments such as laser scanners and photogrammetric scanners. Line or point scan methods by laser can generate precise 3D geometry but cannot obtain color textures in general. Reversely, 3D image modeling with photogrammetry can generate not only geometries but also textures from associated polygons. We got various 3D image models and introduced the process of getting 3D image model of an internet-connected watchdog robot.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.9-19
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• 2010

Every car manufacturer desires to reduce the new car development time spent in improving the safety, NVH, lightweight, reliability and environment friendly features of the car. Other considerations such as planning, exterior and interior styling, packaging, color, and material selection increase the complexity of the car design process. This paper proposes a personal DDP (Digital Design Process) to utilize the engineering analysis and design/styling software for car design. DDP can be efficiently used by a team of car research center or a studio with small number of engineers, helping ordinary engineers becoming ambidextrous in design as well as engineering applications. The concept model starts from idea sketch, rendering, and 3D surface model with CAS (Computer Aided Styling) to the final safety estimation by using proposed DDP based on engineering technology (CAD, CAE). The concept model proposed a hydrogen fuel cell sports coupe which could be available within next 10 years. The proposed DDP can not only reduce the new car development time but also be adapted into designing of varied products such as aircraft, yacht, electrical equipment and sports gear.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.2
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• pp.69-78
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• 2003

In this paper, we develop the so-called functional test model for magnetic bearing wheels. The functional test model developed in this paper is a kind of electromagnetic suspension systems and has three degree of freedom, which consists of one axial suspension from gravity and the other two axes gimbaling capability to small angle, and does not include the motor. For the control of the functional test model, we derive the optimal electromagnetic forces based on the least squares method, and use the proportional-integral derivative controller. Then, we develop a hardware setup, which mainly consists of the digital signal processor and the 12-bit analog-to-digital and digital-to-analog converters, and show the experimental results.