• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.189-199
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• 2014

Floodplain is a flat plain between levees and rivers. This paper suggests a methodology for analyzing the land uses in the Nakdong River floodplain using the RapidEye imagery and the given LiDAR(LIght Detection And Ranging) DEM(Digital Elevation Models). First, the levee boundaries are generated using the LiDAR DEM, and the area of the floodplain is extracted from the given RapidEye imagery. The land uses in the floodplain are identified in the extracted RapidEye imagery by the ISODATA(Iterative Self-Organizing Data Analysis Technique Analysis) clustering. The overall accuracy of the identified land uses by the ISODATA clustering is 91%. Analysis of the identified land uses in the floodplain is implemented by counting the number of the pixels constituting the land cover clusters. The results of this research shows that the area of the river occupies 46%, the area of the bare soil occupies 36%, the area of the marsh occupies 11%, and the area of the grass occupies 7% in the identified floodplain.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.645-651
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• 2015

The objective of this study is to experimentally investigate the effect of design parameter on the mass ratio of a central-driven ejector. The design parameters are the primary nozzle area and distance ratios, diffuser exit-area ratio and mixing-tube length ratio. The experimental setup was an open-loop continuous circulation system which has a movable nozzle ejector, an electric motor-pump, a water tank, a control panel and high-speed camera unit. We calculated the mass ratio using the measured primary and suction-flow rates with the experimental parameter of primary water-flow rate or pressure. The results showed that the mass ratio increased with the primary nozzle distance ratio and mixing tube length ratio, while the mass ratio decreased with the primary nozzle-area ratio and diffuser exit-area ratio.

• Composites Research
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• v.29 no.6
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• pp.401-407
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• 2016

IPMC is composed of thin ion conductive polymer film sandwiched between metallic electrodes plated on both surfaces. Ionic Polymer-Metal Composite (IPMC) generates voltages when bent by mechanical stimuli. IPMC has a potential for the variety of energy harvesting applications due to its soft and hydrophilic characteristics. However, the large-scale implementation is necessary to increase the output power. In this paper, the scale-up of surface area effect on voltage generation characteristics of IPMC was investigated using IPMC samples with different surface areas. Also, a circuit model simulating both the output voltage and its offset variations was designed for estimating the voltages from IPMC samples. The proposed model simulated the output voltages with offsets well corresponding to various frequencies of input bending motion. However, some samples showed that the increase of error between real and simulated voltages with time due to the nonlinear characteristic of offset variations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.3
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• pp.83-92
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• 2004

In this thesis, a modified interpolation-2 6-bit 70MHz ADC is proposed minimizing chip area and power consumption, which includes an error correction circuit. The conventional flash ADC without interpolation comparators suffers from large chip area and more power consumption due to 2n resistors and 2n-1 comparators. Although the flash ADC with interpolation-4 comparators has small area, SNR, INL and DNL are degraded by comparison with the interpolation -2 comparator. We fabricated the proposed 6-bit ADC with interpolation-2 comparators using 0.18${\mu}{\textrm}{m}$ CMOS process. The ADC is composed of 32-resistors, 31 comparators, amplifiers, latches, error correction circuit, thermometer code detector and encoder As the results, power consumption is reduced to 40mW at 3.3V which is saving about 50% than a flash ADC without interpolation comparators, and area is reduced by 20%. SNR is increased by 75% in comparison with that of a flash ADC with interpolation-4 comparators.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.6
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• pp.77-87
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• 2001

This paper describes a design of cryptographic processor that implements the Rijndael cipher algorithm, the Advanced Encryption Standard algorithm. It can execute both encryption and decryption, and supports only 128-bit block and 128-bit keys. As the processor is implemented only one round, it must iterate 11 times to perform an encryption/decryption. We implemented the ByteSub and InvByteSub transformation using the algorithm for minimizing the increase of area which is caused by different encryption and decryption. It could reduce the memory size by half than implementing, with only ROM. We estimate that the cryptographic processor consists of about 15,000 gates, 32K-bit ROM and 1408-bit RAM, and has a throughput of 1.28 Gbps at 110 MHz clock based on Samsung 0.5um CMOS standard cell library. To our knowledge, this offers more reduced memory size compared to previously reported implementations with the same performance.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.313-324
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• 2009

We explore the effect of particle shape and size on 3-dimensional (3D) network and pore structure of porous earth materials composed of glass beads and silica gel using NMR micro-imaging in order to gain better insights into relationship between structure and the corresponding hydrologic and seismological properties. The 3D micro-imaging data for the model porous networks show that the specific surface area, porosity, and permeability range from 2.5 to $9.6\;mm^2/mm^3$, from 0.21 to 0.38, and from 11.6 to 892.3 D (Darcy), respectively, which are typical values for unconsolidated sands. The relationships among specific surface area, porosity, and permeability of the porous media are relatively well explained with the Kozeny equation. Cube counting fractal dimension analysis shows that fractal dimension increases from ~2.5－2.6 to 3.0 with increasing specific surface area from 2.5 to $9.6\;mm^2/mm^3$, with the data also suggesting the effect of porosity. Specific surface area, porosity, permeability, and cube counting fractal dimension for the natural mongolian sandstone are $0.33\;mm^2/mm^3$, 0.017, 30.9 mD, and 1.59, respectively. The current results highlight that NMR micro-imaging, together with detailed statistical analyses can be useful to characterize 3D pore structures of various porous earth materials and be potentially effective in accounting for transport properties and seismic wave velocity and attenuation of diverse porous media in earth crust and interiors.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.85-93
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• 2001

The inter-relationship and combining abilities of characters for leaf length, leaf width, branch number, leaf number, leaf area, fresh weight and dry weight were studied in the F₁ combination of 15 crosses from the partial six-parent diallel cross in Petunia hybrida. The leaf area, fresh weight and dry weight showed high positive correlation together with the other growth characters such as leaf length, leaf width, branch number, leaf number. The mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the growth characters. The estimates of variance components of SCA were greater than those of GCA for all the characters, showing preponderance of non-additive gene actions for these characters. GCA effect was high in the lines of D and G for leaf length and fresh weight, and in the lines of C and D for branch number, leaf number, leaf area and fresh weight. The crosses of D×E, D×G, and E×G exhibited high SCA effect for all the growth characters such as leaf length, leaf width, branch number, leaf number, leaf area, fresh weight, and dry weight. The broad sense heritability was generally high compared to narrow sense one in the 7 characters. The highest heritability of the broad and narrow sense was shown in the leaf width and dry weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.187-202
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• 1976

Experiment were conducted to study the photosynthetic ability of several rice varieties and the influence of the drymatter production on the yield components of the rice plant, especially in ripening period. The photosynthetic ability at the ripening period, the varieties were classified into two groups as relatively high capacity and low capacity. With the earlier the transplanting date and the higher the N-content leaf blade, the greater the ratio of reserved assimilates befere heading time to the ear. This could be support the fact that the rate of full-ripened grains or grain yield of 'Tongil' variety may increased by the change of environment condition.condition.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.1-12
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• 2013

This paper explores design space of many-core processors for a fire feature extraction algorithm. This paper evaluates the impact of varying the number of cores and memory sizes for the many-core processor and identifies an optimal many-core processor in terms of performance, energy efficiency, and area efficiency. In this study, we utilized 90 samples with dimensions of $256{\times}256$ (60 samples containing fire and 30 samples containing non-fire) for experiments. Experimental results using six different many-core architectures (PEs=16, 64, 256, 1,024, 4,096, and 16,384) and the feature extraction algorithm of fire indicate that the highest area efficiency and energy efficiency are achieved at PEs=1,024 and 4,096, respectively, for all fire/non-fire containing movies. In addition, all the six many-core processors satisfy the real-time requirement of 30 frames-per-second (30 fps) for the algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.597-603
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• 2006

The purpose of this study is to improve the short term rainfall forecast skill using neural network model that can deal with the non-linear behavior between satellite data and ground observation, and minimize the flood damage. To overcome the geographical limitation of Korean peninsula and get the long forecast lead time of 3 to 6 hour, the developed rainfall forecast model took satellite imageries and wide range AWS data. The architecture of neural network model is a multi-layer neural network which consists of one input layer, one hidden layer, and one output layer. Neural network is trained using a momentum back propagation algorithm. Flood was estimated using rainfall forecasts. We developed a dynamic flood inundation model which is associated with 1-dimensional flood routing model. Therefore the model can forecast flood aspect in a protected lowland by levee failure of river. In the case of multiple levee breaks at main stream and tributaries, the developed flood inundation model can estimate flood level in a river and inundation level and area in a protected lowland simultaneously.