• Research in Mathematical Education
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• v.5 no.1
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• pp.1-12
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• 2001

Generating fractal images by graphing calculators such as TI_92 combines several important features, which convey the excitement of a living, changing mathematics appropriate to secondary or post-secondary students. The topic of fractal geometry can be illustrated using natural objects such as snowflakes, leaves and ferns. These complex and natural forms are often striking fantastic and beautiful. The examples highlight the fact that complex, natural behaviors can result from simple mathematical rules such as those embodied in iterated function systems(IFS). The visual splendor beauty of fractals, in concert with their ubiquity in nature, revels the intellectual beauty of nonlinear mathematics in a compelling way. The window is now open for students to experience and explore some of the wonder of fractal geometry.

• Animal cells and systems
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• v.16 no.1
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• pp.1-10
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• 2012

Most living organisms synchronize their physiological and behavioral activities with the daily changes in the environment using intrinsic time-keeping systems called circadian clocks. In mammals, the key molecular features of the internal clock are transcription- and translational-based negative feedback loops, in which clock-specific transcription factors activate the periodic expression of their own repressors, thereby generating the circadian rhythms. CLOCK and BMAL1, the basic helix-loop-helix (bHLH)/PAS transcription factors, constitute the positive limb of the molecular clock oscillator. Recent investigations have shown that various levels of posttranslational regulation work in concert with CLOCK/BMAL1 in mediating circadian and cellular stimuli to control and reset the circadian rhythmicity. Here we review how the CLOCK and BMAL1 activities are regulated by intracellular distribution, posttranslational modification, and the recruitment of various epigenetic regulators in response to circadian and cellular signaling pathways.

• The Journal of the Acoustical Society of Korea
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• v.1 no.1
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• pp.19-26
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• 1982

n optimization technique is adapted to determine the stage enclosure configuration preferred by performers. The merit function which quantifies the ease of ensemble among the performers is derived from a set of qualitative conditions recommended by researchers of hall acoustics. The ray path tracing technique based on the modified method of images is used to analyze acoustical characteristics at any locations of performers in stage enclosure. The gradient search technique is employed to find the geometric parameters which maximmize the merit function. As an example, optimum stage enclosure configuration of the trio chamber music is obtained using the computer program developed. The developed technique can be used in the design of concert hall stage and also in forming a special enclosure with movable reflecting surfaces.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.437-477
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• 1994

The DNA replication of human Iyrnphocvtes was studied using Bromodeo3fyuridine incorporation. The characteristic patterns of dvnamlc banding were analysed. Human chromosomal ONA was synthesized in a segmental but highly coordinated fashion. Each chromosome replicates according to its innate pattern of chromosome structure (bandinsl. R-positive bands are demonstrated as the initiation sites of DNA synthesis, and G-bnads initiate replication after it has been completed in the autosomal R-bands. Many researchers demonstrated that developmental or induced methvlation of DNA can inactivate the associated gene loci. Such DNA methylation can be reversed and specific genes reactivated by treatment with 5-azacvtidine. We treated the hvpomethvlating agent 5-azacvtidine and tested for changes of DNA replication pattern. Treatment with 5-azacytidine causes an advance in the time of replication. These observed changes in timing of replication suggest that DNA methvlation may modify regional groups of genes in concert.

• Animal cells and systems
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• v.12 no.4
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• pp.261-267
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• 2008

The human chromosomes 2, 7, 12 and 17 show genomic homology around Hox gene clusters, is taken as evidence that these paralogous gene families might have arisen from a ancestral chromosomal segment through genome duplication events. We have examined protein data from vertebrate and invertebrate genomes to analyze the phylogenetic history of multi-gene families with three or more of their representatives linked to human Hox clusters. Topology comparison based upon statistical significance and information of chromosome location for these genes examined have revealed many of linked genes coduplicated with Hox gene clusters. Most linked genes to Hox clusters share the same evolutionary history and are duplicated in concert with each other. We conclude that gene families linked to Hox clusters may be suggestion of ancient genome duplications.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.1-13
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• 1997

First- and second-order kinetic oxidation rates of trichlorobenzenes (TCBs) were obtained and compared by a chemical activation system (CAS) which mimics mixed functional oxidase activity. The system consists of EDTA, ferrous sulfate, ascorbic acid, and $H_2O_2$ in potassium phosphdte buffer (monobasic at pH 7.4). The rate of transformation in CAS was enhanced in the presence and absence of catalase in the sequence 1, 2, 3-TCB < 1, 2, 4-TCB < 1, 3, 5-TCB. In general, the rates of degradation were greater in the test media with catalase. The effect of photolysis on the degradation of the TCBs with the CAS were examined. Sensitized photolysis with nitrite, Fenton's reagent, TiO$_2$ and triethylamine (TEA) studied in concert with the CAS demonstrated significant enhancement of the degradation rate of TCBs. Disappearance rates of TCBs in CAS with prior photolysis or prior photosensitization were at least 10-fold higher than the sum of the rate for each single experiment. This study proves that the combination of the CAS and photolysis can be used as a suitable technique for enhancing degradation of TCBs in aqueous systems.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.63-69
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• 2017

Nuclear factor I-C (NFI-C) plays a pivotal role in various cellular processes such as odontoblast and osteoblast differentiation. Nfic-deficient mice showed abnormal tooth and bone formation. The transplantation of Nfic-expressing mouse bone marrow stromal cells rescued the impaired bone formation in $Nfic^{-/-}$ mice. Studies suggest that NFI-C regulate osteogenesis and dentinogenesis in concert with several factors including transforming growth factor-${\beta}1$, $Kr{\ddot{u}}ppel$-like factor 4, and ${\beta}$-catenin. This review will focus on the function of NFI-C during tooth and bone formation and on the relevant pathways that involve NFI-C.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1445-1448
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• 2000

이 논문에서는 개념간의 애매한 관계를 적절히 표현할 수 있는 퍼지 개념 계층을 참조하여 최하위 개념 수준에서부터 최상위 개념 수준까지 각 수준에서 연관 규칙을 추출하는 다중 수준 상향식 연관규칙 마이닝 방법을 제안한다. 상위 개념 수준에서 빈발 항목 집합을 구하는데 필요한 상위 개념 수준의 트랜잭션 데이터베이스를 생성하는 방법을 소개한다. 또한 제안한 방법의 응용성을 보이기 위해 실험 과정과 결과를 보인다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.169-170
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• 2006

Advanced melting technology is now being employed in the manufacture of stainless steel powders. The new process currently includes electric arc furnace (EAF) technology in concert with Argon Oxygen Decarburization (AOD), High Performance Atomizing (HPA) and hydrogen annealing. The new high performance-processing route has allowed the more consistent production of existing products, and has allowed enhanced properties, such as improved green strength and green density. This paper will review these processing changes along with the potential new products that are being developed utilizing this technology. These include high strength stainless steels such as duplex and dual phase as well as stainless steel powders used in high temperature applications such as diesel filters and fuel cells.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.390-397
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• 2011

G protein-coupled receptor kinases (GRKs) and ${\beta}$-arrestins have been known as regulators of G protein-coupled receptors. However, it has been recently reported that GRKs and ${\beta}$-arrestins mediate receptor-mediated cellular responses in a G proteinin-dependent manner. In this scheme, GRKs work as a mediator or a scaffold protein. Among 7 members of the GRK family (GRK1-GRK7), GRK2 is the most extensively studied in vitro and in vivo. GRK2 is involved in cellular migration, insulin signaling, and cardiovascular disease. GRK6 in concert with ${\beta}$-arrestin 2 mediates chemoattractant-stimulated chemotaxis of T and B lymphocytes. GRK5 shuttles between the cytosol and nucleus, and regulates the activities of transcription factors. GRK3 and GRK4 do not seem to have striking effects on cellular responses other than receptor regulation. GRK1 and GRK7 play specific roles in regulation of rhodopsin function. In this review, these newly discovered functions of GRKs are briefly described.