• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3918-3934
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• 2017

This paper presents a viewport resolution scaling technique to reduce power consumption in mobile graphic processing units (GPUs). This technique controls the rendering resolution of applications in proportion to the resolution factor. In the mobile environment, it is essential to find an effective resolution factor to achieve low power consumption because both the resolution and power consumption of a GPU are in mutual trade-off. This paper presents a resolution factor that can minimize image quality degradation and gain power reduction. For this purpose, software and hardware viewport resolution scaling techniques are applied in the Android environment. Then, the correlation between image quality and power consumption is analyzed according to the resolution factor by conducting a benchmark analysis in the real commercial environment. Experimental results show that the power consumption decreased by 36.96% on average by the hardware viewport resolution scaling technique.

• Korean Journal of Computational Design and Engineering
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• v.16 no.6
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• pp.407-413
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• 2011

Augmented reality technology can provide computer-generated information to user effectively, therefore many industries have been trying to adopt AR technology to own domain field. Shipbuilding and offshore industry are also trying to introduce the technology, especially in education field. We have already studied about transporter education system based on augmented reality to help understanding for non-expert engineers. Once our previous study was focused on improving of rendering quality, this paper focuses on effective interaction between engineers and system to more increase educational results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.551-554
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• 2002

The paper discusses new approach for machining operation simulation using enhanced Z map algorithm. To extract the required geometric information from NC code, suggested algorithm uses supersampling method to enhance the efficiency of a simulation process. By executing redundant Boolean operations in a grid cell and averaging down calculated data, presented algorithm can accurately represent material removal volume though tool swept volume is negligibly small. Supersampling method is the most common form of antialiasing and usually used with polygon mesh rendering in computer graphics. The key advantage of enhanced Z map model is that the data structure is same with conventional Z map model, though it can acquire higher accuracy and reliability with same or lower computation time. By simulating machining operation efficiently, this system can be used to improve the reliability and efficiency of NC machining process as well as the quality of the final product.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.69-72
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• 2004

In this paper, we measured the electrical and optical characteristics of an electrodeless fluorescent lamp system as product of the inside and outside of the country and compared the measured data. Output current wave of domestic 150 W is unstable than it's of Endura 150 W. But the former of spend time after discharging and output current value is small than the latter. And optical characteristics(brightness, flux, color rendering index, efficiency) value of the former is a little small than the latter. In conclusion, if we improve a little more quality then we must secure the superiority in competition.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.21-24
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• 2004

In this paper, we measured the optical characteristics of the electrodeless fluorescent lamp system as product of the inside and outside of the country and compared the measured data. Power consumption wave of domestic 150 W is unstable than it's of Endura 150 W. Optical characteristics(luminance, luminous flux, color rendering index, efficiency, CIE chromaticity coordinate) value of the former is a little small than the latter. In conclusion, if we improve a little more quality then we must secure the superiority in competition.

• Journal of information and communication convergence engineering
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• v.8 no.3
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• pp.323-327
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• 2010

Recently, the television market trend is change to HD television and the need of the study on HD image enhancement is increased rapidly. To enhancement of image quality, the retinex algorithm is commonly used. That's why we studied how to accelerate the retinex algorithm with CUDA on GPGPU (general purpose graphics processing unit). Calculating average part in retinex algorithm is similar to pyramidal calculation. We parallelize this recursive pyramidal average calculating for all layers, map the average data into the 2D plane and reduce the calculating time dramatically. Sequential C code takes 8948ms to get the average values for all layers in $1024{\times}1024$ image, but proposed method takes only only about 0.9ms for the same image. We are going to study about the real-time HD video rendering and image enhancement.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.1
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• pp.24-28
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• 2004

Metal halide lamps have been made suitable for use in outdoor illumination systems over many years. They are also widely used in application and commercial lighting due to their attracting properties such as good quality color, rendering and high efficiency. Over the past few years, a considerable number of studies have been conducted on the electronic ballast with hot restarting and resonance phenomenon. However, very few attempts have been made at the adaptive ignition method according to lamp state. This paper proposes an electronic ballast for metal halide lamps with an igniter for adaptive ignition. The proposed electronic ballast can generate different ignition voltages according to the arc tube state. The experimental results showed that the proposed ballast circuit using adaptive igniter is suitable for 70W HQI lamps.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.27-33
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• 2016

In this study we propose a method for 3D landform reconstruction and object modeling method by generating contour lines on the map using a depth sensor which abstracts characteristics of geological layers from the depth map. Unlike the common visual camera, the depth-sensor is not affected by the intensity of illumination, and therefore a more robust contour and object can be extracted. The algorithm suggested in this paper first abstracts the characteristics of each geological layer from the depth map image and rearranges it into the proper order, then creates contour lines using the Bezier curve. Using the created contour lines, 3D images are reconstructed through rendering by mapping RGB images of the visual camera. Experimental results show that the proposed method using depth sensor can reconstruct contour map and 3D modeling in real-time. The generation of the contours with depth data is more efficient and economical in terms of the quality and accuracy.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2057-2059
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• 1998

In order to maintain a high quality output voltage, conventional UPS systems use complex filters with large passive components. To overcome this drawback, real time feedback control schemes have been invested. However, these techniques require a high inverter switching frequency to dynamically adapt to changing load conditions reduce harmonics of the output voltage, thereby rendering the system inadequate for high power applications. This paper presents real time digital signal processor(DSP) control of a large capacity UPS system feeding nonlinear loads to provide a sinusoidal inverter output voltage, unity input power factor, low bus voltage ripple, and excellent transient response.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.452-454
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• 2015

This paper provides the coding performance comparisons of depth map resolution in 3D video system. In multiview plus depth map system, depth map is used for synthesis view rendering, and affects to synthesis views quality. In the paper, we show the experimental results as depth map resolution in 3D video system, and show performance variation as dilation filter.