• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.198-198
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• 2006

We have identified sodium benzanilide (Na-BA), sodium diphenyl amine (Na-DPA) and sodium deoxibenzoin (Na-DB) as very efficient initiators for the living anionic polymerization of HIC. It has a slow propagation rate with the additive function of chain end protection, offering in the process a perfect control over MW and MWD. The well-defined amphiphilic coil-rod, coil-rod-coil, and rod-coil-rod block-copolymers of PHIC and P2VP with controlled architecture have been synthesized for the first time with ${\sim}100\;%$ yields. The resulting block copolymers showed lamellar film, donuts, solid and hollow micelles, by simply varying the solvents and the block compositions.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.267-270
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• 2003

This paper proposes high performance $8{\times}8$ multiplier using current-mode quaternary logic technique. The multiplier is functionally partitioned into the following major sections: partial product generator block(binary-quaternary logic conversion), current-mode quaternary logic full-adder block, quaternary-binary logic conversion block. The proposed multiplier has 4.5ns of propagation delay and 6.1mW of power consumption. Also, this multiplier can easily adapted to binary system by the encoder, the decoder. This circuit is simulated under 0.35um standard CMOS technology, 5uA unit current, and 3.3V supply voltage using Hspice.

• Journal of the Speleological Society of Korea
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• no.87
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• pp.8-13
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• 2008

The automatic firewall block and fire alarm system was embodied by using gas circuit and wireless communication equipment, using a smoke sensor (ST-QA1A) and RF Module. OR-CAD was also used for testing circuit system and experiment circuit after assembling circuit. As a result in experiment, the gas sensor detected well an imaginary smoke and worked reliably for driving action of firewall block motor and wireless warning alarm. Through the smoke sensitive perception from the fire, the warning alarm and the preventing fire propagation from the specific closed region were verified reliably. The gas sensor and RF module for firewall and fire alarm system were actually available.

• Journal of the Korean Ceramic Society
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• v.36 no.8
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• pp.876-885
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• 1999

In order to develop high performance basic dam block for tundish vessel in steel-making binders and additives on hydration and thermal characteristics of magnesiz castable refractories were studied. Crack initiation and propagation in cement bonded magnesia castables due to slaking of magnesia clinker at drying process were suppressed by using spinel clinker instead of magnesia powder. In case of Na2O$.$2CaO$.$P2O5(NC2P) bonded castable crack initiation due to slaking of magnesia clinker did not occur but bending strength at high temperature was low. Mechanical properties of NC2P bonded castable refractories at high temperature were improved by using magnesia clinker that contains low SiO2 contents.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.1
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• pp.57-65
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• 1991

It is experimented under rotary bending stress that the spacing of two micro hole flaws is adjacent and that it is distant. In order to observe the behavior of fatigue crack propagation, two kinds of specimens are tested under constant stress and periodic overstressing. Although the crack occurs faster when two micro-hole flaws are adjacent than when they are distant, but there is no difference of the number of fracture cycles between two. The crack propagates slower under low-high block stress than under high-constant stress, and it propagates faster under high-low block stress than under low-constant stress. The influence of two-step block stress is serious right after the stress varies.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.131-137
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• 2007

I intend to seek the shortest path which an aircraft safely flies to its destination through the shadow volume of three dimensional terrain which propagation does not extend. Herein, I propose a method in which a relatively wide shadow volume is divided with a polygon type of block polygon, a path up to the intermediate destination is sought in the divided block polygons according to the weight, and then, the shortest path up to the final destination is sought by repeating courses for seeking a destination again from the adjacent polygon based on the starting point of the intermediate destination within the divided polygon. The shortest path was searched by using the revised algorithms which apply to a critical angle from graph growth algorithms on the shadow volume which propagation on the actual three dimensional terrain does not extend to. The experiment shows that a method proposed in this paper creates effective flying curves.

• Convergence Security Journal
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• v.23 no.2
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• pp.3-10
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• 2023

In the malware distribution network existing on the web, there is a central node that plays a key role in distributing malware. If you find and block this node, you can effectively block the propagation of malware. In this study, a centrality search method applied with risk analysis in a complex network is proposed, and a method for finding a core node in a malware distribution network is introduced through this approach. In addition, there is a big difference between a benign network and a malicious network in terms of in-degree and out-degree, and also in terms of network layout. Through these characteristics, we can discriminate between malicious and benign networks.

• Journal of the Korean GEO-environmental Society
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• v.15 no.5
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• pp.31-37
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• 2014

In situ investigations and laboratory tests using elastic wave have become popular in geotechnical and geoenvironmental engineering. Propagation velocity of elastic wave is the key index to evaluate the ground characteristics. To evaluate this, various methods were used in both time domain and frequency domain. In time domain, the travel time can be found from the two points that have the same phase such as peaks or first rises. Cross-correlation can also be used in time domain by evaluating the time shift amount that makes the product of signals of input and received waveforms maximum. In frequency domain, wave propagation velocity can be evaluated by computing the phase differences between the source and received waves. In this study, wave propagation velocity evaluated by the methods listed above were compared. Bender element tests were conducted on the specimens cut from the undisturbed hand-cut block samples obtained from Block 37 excavation site in Chicago, IL, US. The evaluation methods in time domain provides relatively wide range of wave propagation velocities due to the noise in signals and the sampling frequency of data logger. Frequency domain approach provides relatively accurate wave propagation velocities and is irrelevant to the sampling frequency of data logger.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.4
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• pp.399-407
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• 2002

In this paper, a novel algorithm is proposed to reduce the blocking artifacts of block-based coded images by using block classification and MLP. In the proposed algorithm, we classify the block into four classes based on a characteristic of DCT coefficients. And then, according to the class information of neighborhood block, adaptive neural network filter is performed in horizontal and vertical block boundary. That is, for smooth region, horizontal edge region, vertical edge region, and complex region, we use a different two-layer neural network filter to remove blocking artifacts. Experimental results show that the proposed algorithm gives better results than the conventional algorithms both subjectively and objectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.63-69
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• 1998

The slope revegetation methods in Korea are generally the hydroseeding mixed with perennial herbs, soil, fibers, and fertilizer in consideration of scenic landscape rather than ecological and engineering effect. But perennial herbs can't protect the slope from deep surface erosion and they are not tall enough to create the original naturalness at the boundary parts of existing woodlands. This study is about the slope revegetation method using nutritional propagation capacity of plants and the experimental construction was carried out on the cut-slope of Yongin Hoam C.C. We dug several trenches to a depth of 80cm and at intervals of 150cm from each other. After placing various kinds of live branches(Salix species) into the trench, we backfilled with the excavated soils and finally sprayed water mixed with soil-stabilizer, fertilizer. As six months passed, we made a vegetation research and check the slope surface erosion. Vegetation research was performed in examining the frequency of each block using transect method. 31 kinds of plant species appeared in total area($113.6m^2$) and the dominant species are Setaria viridis, Artemisia rubripes, Persicaria pubescens, Plantago asiatica, Cyperus amuricus, Commelina communis. Among the examined blocks, '아', the top part of the slope, showed the ratio of 1.4 as the highest Alpha-diversity. With regard to life form, therophytes were shown dominant distribution of 58% of total species and neophytes relatively low distribution of 16%. It can be estimated that there is no ecological stabilization of this slope, because of ruderal species' occupation of 74% in total area. Regarding the slope stabilization, the serious surface erosion didn't take place in spite of heavy rainfall this year, but a little surface erosion took place at the block where no other species coming from outside of the site were found.