• Korean Journal of Computational Design and Engineering
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• v.12 no.1
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• pp.15-26
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• 2007

We have developed a method that enables a user to better understand and enjoy the contents of 3D digital archives, thereby enhancing the user's experience. The system's interactive interface, built using virtual reality technology, enables the user to "walk through" the archives, comparing two or the same content at different points in time. For example, a user can compare the proposed design for a building with the actual building and can compare the states of restoration of a cultural heritage site over time. This ability to perform multilateral comparisons enables the user to clarify the relationship between contents, the influence of one content on another, and the causal relationship between contents. Testing of a prototype system for a 3D digital archive of cultural heritage sites showed that it worked smoothly and that the users could easily operate the navigation system.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.229-230
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• 2011

This paper presents deadbeat controller for output current in the utility-interactive inverter. The time delay related with deadbeat controller is compensated by using prediction control. By computer simulation and experiment, the dynamic characteristics of deadbeat controller is verified.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.252-255
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• 1990

Analyzing and simulating of today's complex electrical networks require the use of computer-aided engineering tools. In recent years, the rapid advances in micro-computer hardware technology have increased the availability of power application software on the personal computer, once the domain of mainframes and minicomputers, enabling efficient and cost-effective power system analysis. An interactive simulation and analysis software for a power system is developed and presented in this paper. The software is written in PASCAL and is designed for PC use. This paper presents an integrated software package to run PC-DOS for the analysis of electric power networks. The software is menu driven and controlled by prompts. These programs are intended to help users understand the process of power system analysis and design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1064-1070
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• 2007

This paper presents a grid-interactive current controlled voltage source inverter (CCVSI) with uniterruptible power supply (UPS), which uses an inner current control loop (polarized ramp time (PRT)) and outer feedback control loops to improve grid power quality and UPS. To reduce the complexity, cost and number of power conversions, which results in higher efficiency, a single stage CCVSI is used. The operation of this system could be divided into the power quality control (PQC) state mode and the UPS state mode. In PQC mode, the system operated to compensate the reactive power demand by nonlinear load or variation in load. In UPS mode. the system is controlled to provide a sinusoidal voltage at the rated value for the load when the gird fail. To verify the proposed system, a comprehensive evaluation with theoretical analysis, simulation and experimental results for 1KVA load capacity is presented.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.11-14
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• 2007

In recent years, installation of the new and renewable energy system is rapidly increasing. Because the new and renewable energy system is a practical distributed generation system to save energy resources and to keep environments clean. Conventional single-phase utility interactive inverter controls output current by using PI current controller. However, this method is insufficient to suppress harmonic current resulted from nonlinear loads in grid line. In this paper, in order to suppress periodic waveform distortion and improve THD(Total Harmonic Distortion), new type current controller added a parallel repetitive controller is proposed and then performance of the proposed controller was verified with computer simulation.

• International Journal of Contents
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• v.2 no.2
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• pp.1-5
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• 2006

The modeling and animation of natural phenomena have received much attention from the computer graphics community. Synthetic of natural phenomena are required for such diverse applications as flight simulators, special effects, video games and other virtual realty. In special effects industry there is a high demand to convincingly mimic the appearance and behavior of natural phenomena such as smoke, waterfall, rain, and fire. Particle systems are methods adequate for modeling fuzzy objects of natural phenomena. This paper presents particle system API(Application Program Interfaces) for generating special effects in virtual reality applications. The API are a set of functions that allow C++ programs to simulate the dynamics of particles for special effects in interactive and non-interactive graphics applications, not for scientific simulation.

• Journal of Korea Multimedia Society
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• v.20 no.6
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• pp.935-949
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• 2017

The purpose of this study was to analyze the characteristics of virtual manipulatives apps that can be used to teach students struggling to learn mathematics. To achieve this goal, ten general characteristics of 23 virtual manipulatives apps were evaluated. The instructional, interface, and interactive design features of apps were also evaluated on five-point scale ratings of 18 items. In addition, SPSS frequency analysis and the correlation between each feature was analyzed. Frequently presented instructional contents among 23 virtual manipulatives apps were geometry, arithmetic operation, number concept and measurement. The frequently presented level of instructional contents was lower grade elementary school and kindergarten age. The frequently presented instructional type was the simulation. Regarding the design features, instructional design was rated as the highest (mean = 3.7); interactive design (mean = 3.6) and interface design (mean = 3.3) were also rated higher than neural. In addition, as the learning strategy was appropriately presented, it was evaluated that there was less screen linkage and content error.

• Nuclear Engineering and Technology
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• v.42 no.2
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• pp.151-162
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• 2010

A severe accident training simulator that can simulate important severe accident phenomena and nuclear plant behaviors is developed. The simulator also provides several interactive control devices, which are helpful to assess results of a particular accident management behavior. A simple and direct dynamic linked library (DLL) data communication method is used for the development of the simulator. Using the DLL method, various control devices were implemented to provide an interactive control function during simulation. Finally, a training model is suggested for accident mitigation training and its performance is verified through application runs.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.591-594
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• 1999

The application field of photovoltaic system has been increased widely. In the application of photovoltaic system, the utility interactive photovoltaic system(UIPVS) has benefits of not only the home energy saving in domestic system but also reduction of peak power which threaten the capacity of power plant equipment when the maximum power consumption is occurred in daytime. This paper represents the effect of the nonlinear AC load which connected to the UIPVS with parallel connection and introduces the active power filtering(APF) techniques to the UIPVS for the reactive power compensation. The enhancement of source side power quality using APF algorithm is verified using simulation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.376-381
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• 1990

An interactive computer program to design a mold cavity with the proper rigging system has been developed. In addition to the pattern and the risers generated in part 1 of this work, the various components of the gating system are generated in complete three dimensional models by a rational approach. Then they are laid interactively by the user, and united together with the pattern and the risers to result in the three dimensional model of the mold assembly. Finally, the vents and the mold box are constructed following the user's interactive specification and then the mold cavity is completed in a three dimensional geometric model by subtraction the mold assembly and the vents from the mold box. The three dimensional model of a mold cavity is useful for many related applications such as the solidification simulation for mold evaluation and the NC tool path generation for mold production.