• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.56.1-56.1
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• 2014

Although the growth of structure, as traced by galaxy clusters, has been extensively studied through cosmological simulations and large-scale surveys, the early formation and evolution of their galaxy content, and its relation to the transformation of the host environment, are still somewhat poorly understood. This is particularly true of the processes that give rise to the quiescent galaxy population between z=3 and z=2. Recent discoveries at z~2 are now bridging the gap between the well-established massive clusters of the last 9 Gyr and the high-redshift universe, and new datasets are now giving us access to statistical populations of intermediate-mass structures at this epoch. I will discuss the properties of quiescent galaxies in the most distant confirmed X-ray detected galaxy clusters, their implications for galaxy quenching at high-redshift as well as the regulation of star formation at group scales at z~2.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.225-229
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• 1963

The nature of the two isomers of 4-nitroazoxybenzenes in strongly acidic solution have been analyzed by U.V. spectrophotometry. Oxygen atom in the azoxy-group of $\alpha$-and $\beta$-4-nitroazoxybenzene in strong acid solution migrates neither to para position nor ortho position of the unsubstituted benzene ring of the compound in contrast with the cases of methyl-and bromo-substituted azoxybenzene, and shown no Wallach rearrangement. Since the $^1A{\rightarrow}^1H$ bands of the spectra shown hyperchromic effect whereas the ${\pi}{\rightarrow}{\pi}^*$ bands of them exhibit extream hypochromic effect, it appears most likely that trans ${\rightarrow}$cis isomerization take place in the media. A mechanism of a triangular transition state by which the transformation might be proceeded, is proposed.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.664-672
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• 2011

A series of hydrophilic chromophores was synthesized through introduction of dendritic sulfonate anions using click chemistry. A dendron structure bearing several sulfonate groups enhances hydrophilicity of attached chromophores. A click triazole formation connects chromophores with hydrophilic groups. A neutral trichloroethyl sulfonate has versatile features such as easy introduction, chemical endurance for isolation or storage, and convenient transformation to a hydrophilic anion. Zinc and OH mediated cleavage of trichloroethyl group from the neutral sulfonate undergoes to generate a water-soluble sulfonate anion. The solubility was examined with different counter cations and in different pH media and thus increased with the number of attached sulfonate ion. Two hydrophilic chromophores of stilbene-derived and azobenzene-derived dipolar structures exhibit clear negative and positive solvatochromism in protic solvents, respectively.

• Korean Journal of Child Studies
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• v.20 no.2
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• pp.279-297
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• 1999

The process of political and economic transformation of Germany following reunification has been well documented, but the question of psychological reunification is addressed by the present study. In order to analyze how East German adolescents adapted to the changing socialization context following reunification, questionnaires on values orientation, self-efficacy, subjective well being, coping, attitude toward violence and toward reunified German society were administered to 149 high school students. Results indicated that subjects had high scores on value orientation in private life and used active coping strategies. They had high scores in self-efficacy and subjective well being. Their political attitudes were complex and diverse. There were group differences by gender and type of school attended.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.4
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• pp.235-240
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• 2007

A current-balancing segmented group-inverting transmitter is presented for multi-Gb/s single-ended parallel links. With an additional increase of 4 pins, 16-bit data is efficiently encoded to 20 pins to achieve the current balancing and eliminate the simultaneous switching noise. Since the proposed coding is a simple inversion-or-not transformation of pre-defined groups of binary data, it can be implemented with simplified logic circuits. The transmitter is designed with a $0.18{\mu}m$ CMOS technology, and simulated eye diagrams at 5Gb/s show dramatic improvements in signal integrity.

• 대한핵의학회:학술대회논문집
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• 2002.05a
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• pp.32-36
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• 2002

Lymphoma is a group of neoplastic disease of lymphoid tissues, which can be classified into categories of Hodgkin's disease and non-Hodgkin's lymphoma(NHL). Prognosis of lymphoma depends on the extent of disease(staging) especially in Hodgkin's disease, but also depends on the histologic make up in non-Hodgkin's lymphoma. Although non-Hodgkin's lymphoma is a neoplastic transformation of lymphoid cell it is a collection of disease with merphologically and immunologically diverse make up. Consequently the classification of NHL has changed frequently and evolved according to the progress of immunologic and molecular knowledge added to the original morphologic classification. Lymphoma is a disorder sensitive to chemotherapy which often leads to cure of the disease even in advanced stage, while many other patients die from the progression of disease. Therefore, better understanding in newer classification and sensitive imaging technique, such as PET, in lymphoma will likely lead to the improvement of survival rate.

• Journal for History of Mathematics
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• v.17 no.4
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• pp.77-86
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• 2004

Felix Klein profoundly influenced mathematical developments throughout the world by showing a new direction for modem geometry. He also influenced the lives of excellent scientists like Einstein by reforming mathematical education. The first Felix Klein medal of the Internal Commission on Mathematical Instruction was awarded at ICME-10 in July of 2004. In this article, we discuss Klein's Erlangen Program and investigate his influence on modem mathematics and mathematical education with this medal as momentum.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1636-1644
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• 2017

The main purpose of this article is to describe the magnetohydrodynamic stagnation point flow of Walter-B nanofluid over a stretching sheet. The phenomena of heat and mass transfer are based on the involvement of thermal radiation and chemical reaction. Characteristics of Newtonian heating are given special attention. The Brownian motion and thermophoresis models are introduced in the temperature and concentration expressions. Appropriate variables are implemented for the transformation of partial differential frameworks into sets of ordinary differential equations. Plots for velocity, temperature, and nanoparticle concentration are displayed and analyzed for governing parameters. The skin friction coefficient and local Nusselt and Sherwood numbers are studied using numerical values. The temperature and heat transfer rate are enhanced within the frame of the thermal conjugate parameter.

• East Asian mathematical journal
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• v.16 no.2
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• pp.251-266
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• 2000

The problem of solution uniqueness to the task of determining unknown parameters of mathematical models from input-output observations is studied. This problem is known as structural identifiability problem. We offer a new approach for testing structural identifiability of linear state space models. The approach compares favorably with numerous methods proposed by other authors for two main reasons. First, it is formulated in obvious mathematical form. Secondly, the method does not involve unfeasible symbolic computations and thus allows to test identifiability of large-scale models. In case of non-identifiability, when there is a set of solutions to the task, we offer a method of computing functions of the unknown parameters which can be determined uniquely from input-output observations and later used as new parameters of the model. Such functions are called parametric functions capable of estimation. To develop the method of computation of these functions we use Lie group transformation theory. Illustrative example is given to demonstrate applicability of presented methods.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.140-143
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• 1990

Ethanolic tetra carbonylhydridoferrate solution combined with dialdehyde (no of carbon; 4,5,6) is very efficient for the selective transformation of amino group into N-heterocyclic compound. However, a large variety of both aliphatic and aromatic amines react with the ferrate-pimelaldehyde at room temperature under an atmospheric pressure of carbon monoxide to give the corresponding N-(cyclohexylmethyl)-N-alkyiamine derivatives in moderate yields instead of the corresponding N-substituted perhydroazocine derivatives.