• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1209-1220
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• 2019

The demand for virtual reality (VR) is rapidly increasing. Providing the immersive experience requires much operation and many data to transmit. For example, a 360-degree video (360 video) with at least 4K resolution is needed to offer an immersive experience to users. Moreover, the MPEG-I group defined three degrees of freedom plus (3DoF+), and it requires the transmission of multiview 360 videos simultaneoulsy. This could be a burden for the VR streaming system. Accordingly, in this work, a bitrate-saving method using projection conversion is introduced, along with experimental results for streaming 3DoF+ 360 video. The results show that projection conversion of 360 video with 360lib shows a Bjontegaard delta bitrate gain of as much as 11.4%.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1425-1432
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• 2010

In large construction site, although soil conversion factor is so significant to preliminary design, operation design and calculating the cost of construction that it is important to take reasonable estimation and application, the standard of soil conversion factor for weathered ground doesn't clearly suggested yet. So in this study, at first we obtain the image using DSLR - high resolution camera and Laser scanner in the Haeng-Bok city constructin site, then analysis the ratio of soil and rock using various image processing method(Sobel method, Laplace method, Highpass filter, Hue and Saturation analysis). Mutual comparation with the result of image processing analysis and manual segmentation of 5case image in the cad. As a result, best image processing method was different for each case. In case of high propotion of rock, Laplace was best and in case of high propotion of soil, Highpass was best, and mixed case Laplace was best.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.83-88
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• 2002

In this paper, a POS interfacing and temperature compensable LPG dispensing control system(LDCS) has been developed. A LDCS includes a 16-bit 80C196 microprocessor, RAM, ROM, video driver, and programmable peripheral devices. Based on gas flow encoding pulse, temperature-voltage conversion values and apparatus calibration values, the LDCS controls the LPG dispensing quantity with switching on or off the solenoid valves. The temperature compensation is performed with a 10-bit A/D conversion and its range is from +7$0^{\circ}C$ to -3$0^{\circ}C$ with a 0.5$^{\circ}C$ resolution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.819-823
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• 2016

DSSC (dye-sensitized solar cell) is expected to be one of the next-generation photovoltaics because of its environment-friendly and low-cost properties. However, commercialization of DSSC is difficult because of the electrolyte leakage. We propose thermal curable base on silicon resin and apply a unit cell and large area ($200{\times}200mm$) dye-sensitized solar cell. The resin aimed at sealing of DSSC and gives a promising resolution for sealing of practical DSSC. In result, the photoelectric conversion efficiency of the unit cell and the module was 6.63% and 5.49%, respectively. In the durability test result, the photoelectric conversion efficiency of the module during 500, 1,000, 1,500 and 2,000 hours was 0.73%, 0.73%, 1.82% and 2.36% respectively. It was confirmed that the photoelectric conversion efficiency characteristics are constant. We have developed encapsulation material of thermal curing method excellent in chemical resistance. A sealing material was applied to the dye-sensitized solar cell and it solved the problem of durability the dye-sensitized solar cell. Sealing material may be applied to verify the possibility of practical application of the dye-sensitized solar cell.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.301-309
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• 2022

This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and H_p(10) dosimetry approaches. The HVL values of the following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.7
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• pp.317-322
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• 2002

This paper presents a linear temperature/voltage relation over a temperature range(0~100$^{\circ}C$) with high-resolution, reasonably god response linearity, reliability, and overall improved performance. A notable feature of the proposed method is that the whole temperature span is divided by 16 subbands thus the variation span of measured voltage is narrowed. Therefore noise characteristic has been improved. The output voltage is amplified after the uniformed DC voltage component is eliminated by offset. We proposed circuit using median value and mean value of digital signal in order to reduce the noise effect. The proposed circuit offers linear temperature/voltage conversion over a wide dynamic range using DSP(TMS320C31) and steinhart equation.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.10a
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• pp.28-34
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• 1986

The frequency synthesizer for Fast Frequency Hopping System musy be capable of a fast tuning with a small step frequency over wide band. The most conventional frequency synthesizer that uses the phase locked loop (PLL) enables the wide band problem but have a poor side of the low resolution and the transient response. In this paper, we have discussed the experimental results of a direct digital frequency synthesizer which can be applicable to the Fast Frequency Hopping System, using digital-to-analoq (D/A)conversion techniques. With this system we can find the merits of a fine resolution and the possibility of a fast tuning leaving the problems of transent frequency.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.47-50
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• 2002

An extended-counting analog to digital converter (ADC) is designed to have a high resolution(14bit) with low power consumption and small dia area. First order sigma-delta modulator with a simple counter for incremental operation eliminates the need of big decimation filter in conventional sigma-delta type ADC. To improve the accuracy and linearity, extended mode of successive approximation is followed. For 14-bit conversion operation, total 263 clocks(1 clock for reset, 256 clocks for incremental operation and extended 6 clocks for successive approximation operation) are needed with the sampling rate of 10 Ms/s This ADC is implemented in a 0.6um standard CMOS technology with a die area of 1 mm ${\times}$ 0.75 mm.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.85-89
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• 2007

This paper presents the method to provide a fast service for user in image manipulation such as zooming and panning of huge size high resolution satellite image (e.g. Giga bytes per scene). The proposed technique is based on the hierarchical structure that has 3D-Tiling in horizontal and vertical direction to provide the image service more effectively than 2D-Tiling technique in the past does. The essence of the proposed technique is to create tiles that have optimum level of horizontal as well as vertical direction on the basis of current displaying area which changes as user manipulates huge image. So this technique provides seamless service, and will be very powerful and useful for manipulation of images of huge size without data conversion.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.186-190
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• 2005

In this paper, the pipelined A/D converter with multi S/H stage structure is proposed for high resolution and high-speed data conversion rate. In order to improve a resolution and operational speed, the proposed structure increased the sampling time that is sampled input signal. In order to verify the operation characteristics, 20MS/s pipelined A/D converter is designed with two S/H stage. The simulation result shows that INL and DNL are $0.52LSB\~-0.63LSB$ and $0.53LSB\~-0.56LSB$, respectively. Also, the designed Analog-to-Digital converter has the SNR of 43dB and power consumption is 18.5mW.