• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.219-222
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• 2007

Today, use of high resolution satellite image with at least 1m resolution is expanding into many more areas including forest, river way, city, seashore and so forth for disaster prevention. Interest in this medium is increasing among the general public due to the roll-out to the private sector as Google earth, Virtual Earth and so forth. However, pre-processing process that revises the geometrical distortion that result at the time of photographing is required in order to use high resolution satellite image. The purpose of this research is to search the most accurate GCP(Ground Control Point) information acquisition method that is used for the revision of high resolution satellite image's geometrical distortion through automated processing. Through this, it is possible to contribute to increasing the level of accuracy at the time of high resolution satellite image revision and to secure promptness.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1338-1340
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• 2009

High resolution three-dimensional integral imaging display is proposed. Each time-multiplexed image is projected with different incident angle on same array of elemental lenses. Those images are collected at different positions in focal plane of lens array, and thus the number of the point light sources increases and their spacing decreases. Therefore, proposed method can create high resolution 3D images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.1013-1020
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• 2013

In this paper the super-resolution time delay estimation algorithms based on eigen-analysis are developed for spread spectrum signals along with their comparative performance analysis. First, we shall develop super-resolution time delay estimation algorithms using the representative eigen-analysis based AOA (angle-of-arrival) estimation algorithms such as MUSIC, Minimum-Norm, and ESPRIT, and apply them to the ISO/IEC 24730-2.1 real-time locating system (RTLS) employing a direct sequence spread spectrum (DS-SS) technique to compare their performances in RTLS environments. Simulation results illustrate that all the three algorithms can resolve multipath signals whose delay differences are even smaller than the Rayleigh resolution limit. Simulation results also show that MUSIC and Minimum-Norm provide a similar performance while ESPRIT is inferior to both algorithms in RTLS environments.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.70-81
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• 2024

With heavy rainfall due to extreme weather causing increasing damage, the importance of urban flood forecasting continues to grow. To forecast urban flooding accurately and promptly, a sewer network and surface grid with appropriate detail are necessary. However, for urban areas with complex storm sewer networks and terrain structures, high-resolution grids and detailed networks can significantly prolong the analysis. Therefore, determining an appropriate level of network simplification and a suitable surface grid resolution is essential to secure the golden time for urban flood forecasting. In this study, InfoWorks ICM, a software program capable of 1D-2D coupled simulation, was used to examine urban flood forecasting performance for storm sewer networks with various levels of simplification and different surface grid resolutions. The inundation depth, inundation area, and simulation time were analyzed for each simplification level. Based on the analysis, the simulation time was reduced by up to 65% upon simplifying the storm sewer networks and by up to 96% depending on the surface grid resolution; further, the inundation area was overestimated as the grid resolution increased. This study provides insights into optimizing the simplification level and surface grid resolution for storm sewer networks to ensure efficient and accurate urban flood forecasting.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.71-77
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• 2018

The optical time domain reflectometer (OTDR) is the most widely used method to monitor problems with currently installed optical fibers. The OTDR is an instrument designed to test the FTTx network and evaluates the physical properties of the fiber, such as transmission loss and connection loss. It is important to improve the spatial resolution in order to accurately grasp the optical path problems by using the OTDR. When the pulse width is less than twice the distance between the two reflectors, the signals reflected from the two reflectors are reflected without overlap, so that the reflected signal can be distinguished. However, when the pulse width is larger than twice the distance between the two reflectors, so that the reflected signal can not be distinguished. In order to overcome these limitations, this paper proposed a method of improving spatial resolution by applying a super resolution algorithm. As a result of the simulation, the resolution is improved when the super resolution algorithm is applied, and the event interval can be analyzed more precisely.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.4
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• pp.411-417
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• 2012

A Coarse-Fine Time-to-Digital Converter (TDC) using the single time amplifier is proposed. A vernier delay line is used to overcome process dependency and the 2-stage time amplifier is designed to have high resolution by increasing the gain of the time amplifier. Single time amplifier architecture reduces the silicon area of the TDC and alleviates mismatch effect between time amplifiers. The proposed TDC is implemented in $0.18{\mu}m$ CMOS process with the supply voltage of 1.8 V. The measured results show that the resolution of the TDC is 0.73 ps with 10-bit digital output, although highend process is not applied. The single time amplifier architecture reduces 13% of chip area compared to previous work. By reducing the supply voltage, the linearity of the TDC is enhanced and the resolution is decreased to 1.45 ps.

• Macromolecular Research
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• v.13 no.1
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• pp.39-44
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• 2005

Ion-exchange polymeric stationary phases presenting amino acid and amino groups were prepared by the surface grafting of glycidyl methacrylate onto a silica gel surface and subsequent amination. Three kinds of amino acids-L-arginine (Arg), D-lysine (Lys), and D-histine (His)-were used in this study. An ion-exchange polymeric stationary phase presenting ethylene diamine (EDA) was also prepared by surface graft polymerization. Separation of the model proteins bovine serum albumin (BSA), chick egg albumin (CEA), and hemoglobin (Hb) was performed using the amino acid- and amine-derived columns. In separating the CEA/BSA mixture, the resolution time of BSA was longer than that of CEA when using the EDA column, whereas the resolution time of BSA was shorter than that of CEA when using the Arg, Lys, and His columns. In the separation of the Hb/BSA mixture, the resolution time of BSA was longer than that of Hb in the EDA column, whereas the resolution time of BSA was shorter than that of Hb in the amino acid columns (D-Lys, L-Arg, and D-His).

• Atmosphere
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• v.18 no.1
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• pp.55-70
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• 2008

The global time slice approach is a transient experiment using high resolution atmosphere-only model with boundary condition from the low resolution globally coupled ocean-atmosphere model. The present study employs this "time slice concept" using ECHAM4 atmosphere-only model at a horizontal resolution of T106 with the lower boundary forcing obtained from a lower-resolution (T42) greenhouse gas + aerosol forcing experiment performed using the ECHO-G/S (ECHAM4/HOPE-G) coupled model. In order to assess the impact of horizontal resolution on simulated East Asian summer monsoon climate, the differences in climate response between the time slice experiments of the present and that of IPCC SRES AR4 participating 21 models including coarser (T30) coupled model are compared. The higher resolution model from time slice experiment in the present climate show successful performance in simulating the northward migration and the location of the maximum rainfall during the rainy season over East Asia, although its rainfall amount was somewhat weak compared to the observation. Based on the present climate simulation, the possible change of East Asian summer monsoon rainfall in the future climate by the IPCC SRES A1B scenario, tends to be increased especially over the eastern part of Japan during July and September. The increase of the precipitation over this region seems to be related with the weakening of northwestern part of North Pacific High and the formation of anticyclonic flow over the south of Yangtze River in the future climate.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.252-259
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• 1994

The method of calculating overlap dispersion caused by group velocity mismatch between uv and visible pulses in ultrafast pump-probe experiments is presented to discuss limitations of the time resolution and signal intensity. The calculations show arrangements using a single focusing lens shall result in undesirable time resolution and low signal intensity. Achromatic doublets result in unrealistic solutions. However, dramatic improvement in the time resolution and signal intensity is expected in the optical arrangements using separate lens for each pulse and in the arrangements using a cutoff secondary lens with a main lens. lens.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3C
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• pp.368-373
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• 2004

Extremely fine tine resolution of ultra-wideband (UWB) signal poses a new problems to the system designer. A reasonable accuracy of the system clock is necessary to process signals with such a high space resolution. A useful way of illustrating the time resolution of a signal is to evaluate the ambiguity function. The ambiguity function for carrierless UWB defined using the time mismatch and time scaling factor as its two parameters. The UWB ambiguity function is evaluated for various signaling schemes of impulse radio.