• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.9.2-9.2
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• 2011

Ultrathin polyelectrolyte (PE) multilayer films prepared by the versatile layer-by layer (LbL) assembly method have been utilized for the preparation of light-emitting diodes, electrochromic, membrane, and drug delivery system, as well as for selective area patterning and particle surface modification because the various materials with specific properties can be inserted into the film with nano-level thickness irrespective of the size or the shape of substrate. Since the introduction of the LbL technique in 1991 by Decher and Hong, various hydrophilic materials can be inserted within LbL films through complementary interactions (i.e., electrostatic, hydrogen-bonding or covalent interaction). In this study, it is demonstrated that LbL SA multilayer films based on nucleophilic substitution reaction can allow the preparation of the highly efficient magnetic and/or optical films and nonvolatile memory devices.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.93-96
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• 2006

To investigate the properties of high flowing concrete with fly ash and crushed sand for CFT structure, many batches were performed by a trial-error method and the results were analyzed by SPSS software program. In the experiment W/B was set up as 0.25 and the variables were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens (3, 7, 28 days). The results of this study are summarized as the follows; 1) The increase of the substitution ratio of fly ash, the decrease of dosage of SP and the increase of dosage of AEA due to very fine sphere particle of fly ash. 2) The increase of the blend ratio of crushed sand, the increase of dosage of S/a and water content related with viscosity. 3) Made the high flowing concrete, the increase S/a and the increase the water content.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.94-97
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• 2003

Recently, owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field, and the amount of construction waste are rapidly increased. These waste are raised to financial and environmental problems, so the method of reusing waste concretes has been studied and carried out many direction. Especially being want of resources, if waste concrete could be recycled as aggregate for concrete, it will contribute to solve the exhaustion of natural aggregate, in terms of saving resources and protecting environment. This study is that the floating properties of concrete with recycled coarse aggregate were investigated for the substitution of recycled coarse aggregate. The result of this study, in case of water reducing, the property of harden concrete for the substitution ratio of recycled coarse aggregate was increased. The Quality of recycled coarse aggregate concrete was improved by water reducing.

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.132-139
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• 1994

Cognitive Spelling Therapist generates the candidates for correction of one-letter misspelling words, which correspond to over 80 % of the misspelling words. One-letter misspelling can be divided into four categories, and for each categories Cognitive Spelling Therapist copes them with seperate cognitive therapies. Each therapy is based on cognitive causes of misspelling: figural confusion, pronunciation confusion, and keyboard confusion. Cognitive Spelling Therapist generates three candidates for correction in average. After we tested the correctness of candidates with 185 misspelled words randomly sampled from two typist for two months, Cognitive Spell Therapist showed 97.5 % correction for substitution errors, while insertion, deletion, and transposition errors were perfectly corrected.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.22
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• pp.51-57
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• 1990

A new interactive multiobjective decision making technique, which is called the fuzzy sequential proxy optimization technique, has been proposed. This technique is the revised version the sequential proxy optimization technique that the decision-maker's marginal rates of substitution is interpreted as type of L-R fuzzy numbers. It used to the square of normalized scalar product as the doptimalilry condition. However, this technique ignores the imprecise nature of a decision-maker's judgement of marginal rates of substitution. Also, it have a shortcoming that can be only applied over three objective functions. In this paper, considering the imprecise nature of a decision-maker's judgement, we presents an interactive fuzzy decision-making method on the basis of the decision-maker's MRS presented through the use of five types of membership functions including non-linear functions. FORTRAN programs that run in conversational mode are developed to implement man-machine interactive procedure.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.223-228
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• 2003

Recently, owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field, and the amount of construction waste is rapidly increased. These waste are raised to financial and environmental problems, so the method of reusing waste concretes has been studied and carried out many direction. Especially being want of resources, if waste concrete could be recycled as aggregates for concrete, it will contribute to solve the exhaustion of natural aggregate, in terms of saving resources and protecting environment. This study is that the mechanical properties of concrete with recycled coarse aggregate were investigated for types of mineral admixture and the substitution of recycled coarse aggregate. The result of this study, in case of using mineral admixture, the property of fresh concrete was rised. And the property of harden concrete for the substitution ratio of recycled coarse aggregate was decreased. But the property of concrete with mineral admixture was better than that of concrete used only cement.

• Environmental and Resource Economics Review
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• v.10 no.4
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• pp.569-589
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• 2001

We examine historical contributions of inter fuel substitution, changes in carbon efficiency and energy intensity, growth of economy and population to Korea's $CO_2$ emissions from 1970 to 1998 using the log mean weight Divisia index method. The study reveals that economic growth is the most significant factor to $CO_2$ emissions growth among the five factors. Changes in the fuel substitution and carbon coefficient are found negative contributors to $CO_2$ emissions growth. Energy intensity, which played dominant role in halting $CO_2$ emissions growth in the 1980s, began to play reversed role in the 1990s. When evaluated with the log mean Divisia index technique, deterioration of energy intensity in the 1990s is found worse and expected to contribute $CO_2$ emissions growth further.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.89-92
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• 2006

To investigate the properties of high flowing and high strength concrete with crushed sand and fly ash for CFT structure, many batches were performed by a trial-error method. In the experiment W/B was set up three levels as 0.25, 0.30 and 0.35. Also the variables of the experiment were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens(3, 7, 28 days). The results of this study are summarized as the follows; 1) The effect a substitution ratio of fly ash on the compressive strength was not consistent with age. For twenty-eight day compressive strength, the best result was come out when cement was substituted by 10% of fly ash. 2) The decrease of the water binder ratio, the increase of compressive strength and elastic modulus. Also the relationship is very similar to the case of a normal concrete

• Archives of Pharmacal Research
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• v.17 no.3
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• pp.170-174
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• 1994

We have synthesized various 6-substituted 2-oxo-purine nucleosides from key intemediate, 6-[(4-methylphenylthio)-2-oxo-9(2, 3, 5tri-o-acetyl-$\beta$-D-ribofuanoslyl)]-2, 3- dihydropurine in relatively high yields by one step nucleophilic substitution. Various isoguanosine, xanthosine analogs and other 2-oxo-purine nucleosides containing nitrogen, sulfur and oxygen at C-6 of purine base were easily obtained by this method. The structures of the products were established on the basis of their spectral data studies. And cytotoxicity of resulting synthetic 6-substituted-2-oxo-purine nucleosides against some tumor cell-lines was examined. $Ed_{50}$ values of these synthetic compounds were above $100\;{\mu}g/ml$ except isoguanosine, $N^6$-methyl isoguanosine and thioxanthosine analogs.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.8
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• pp.26-33
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• 1994

Optical adders using a modified signed-digit(MSD) number system have been proposed to restrict the carry propagation chain encountered in a conventional binary adder to two positions to the left. But, MSD number system must encode three different states to represent the three possible digits of MSD. In this paper, we propose the design of an optical adder based on 1-bit addition rules by using the method of symbolic substitution (SS). We show that this adder can use binary input which is used by a digital computer, as it is and be implemented by smaller system in size than MSD adder.