• Molecules and Cells
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• v.44 no.7
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• pp.425-432
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• 2021

Aging is associated with functional and structural declines in organisms over time. Organisms as diverse as the nematode Caenorhabditis elegans and mammals share signaling pathways that regulate aging and lifespan. In this review, we discuss recent combinatorial approach to aging research employing C. elegans and mammalian systems that have contributed to our understanding of evolutionarily conserved aging-regulating pathways. The topics covered here include insulin/IGF-1, mechanistic target of rapamycin (mTOR), and sirtuin signaling pathways; dietary restriction; autophagy; mitochondria; and the nervous system. A combinatorial approach employing high-throughput, rapid C. elegans systems, and human model mammalian systems is likely to continue providing mechanistic insights into aging biology and will help develop therapeutics against age-associated disorders.

• Journal of the Chungcheong Mathematical Society
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• v.36 no.3
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• pp.149-153
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• 2023

The aim of this note is to derive two known combinatorial identities via a hypergeometric series approach using Saalschiitz's classical summation theorem.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.4
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• pp.117-134
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• 2004

This study suggests a data driven optimization approach, which simulates the models of human learning processes from cognitive sciences. It shows how the human learning processes can be simulated and applied to solving combinatorial optimization problems. The main advantage of using this method is in applying it into problems, which are very difficult to simulate. 'Undecidable' problems are considered as best possible application areas for this suggested approach. The concept of an 'undecidable' problem is redefined. The learning models in human learning and decision-making related to combinatorial optimization in cognitive and neural sciences are designed, simulated, and implemented to solve an optimization problem. We call this approach 'SLO : simulated learning for optimization.' Two different versions of SLO have been designed: SLO with position & link matrix, and SLO with decomposition algorithm. The methods are tested for traveling salespersons problems to show how these approaches derive new solution empirically. The tests show that simulated learning for optimization produces new solutions with better performance empirically. Its performance, compared to other hill-climbing type methods, is relatively good.

• Information Systems Review
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• v.8 no.2
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• pp.103-117
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• 2006

As the interest in the combinatorial auction has increased, diverse combinatorial auction market types have been proposed. Although there have been several studies on the combinatorial auction design, the studies covered some factors or partial dimensions of combinatorial auction design. Given the potential practical value of combinatorial auctions, it is necessary to approach it with an integrated and systematic design methodology for supporting a comprehensive range of combinatorial auction models. Thus, we present a systematic framework for combinatorial auction design methodology. In particular, we classified the combinatorial auction architecture types, process types, and mechanism types. This framework characterizes the different combinatorial auction models, and lead to a useful taxonomy of the combinatorial auction design factors and taxonomy of the market types by coordination among the design factors. In addition, we illustrate an n-bilateral combinatorial auction market, derived from our design methodology, to show the viability of our study.

• Communications of the Korean Mathematical Society
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• v.34 no.4
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• pp.1117-1133
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• 2019

We find the asymptotic behavior of Kirillov model for irreducible induced representations of $GL_2$ by using combinatorial methods.

• Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.295-311
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• 2016

This paper addresses to the flowshop scheduling problem with blocking constraints. The objective is to minimize the makespan criterion. We propose a hybrid combinatorial particle swarm optimization algorithm (HCPSO) as a resolution technique for solving this problem. At the initialization, different priority rules are exploited. Experimental study and statistical analysis were performed to select the most adapted one for this problem. Then, the swarm behavior is tested for solving a combinatorial optimization problem such as a sequencing problem under constraints. Finally, an iterated local search algorithm based on probabilistic perturbation is sequentially introduced to the particle swarm optimization algorithm for improving the quality of solution. The computational results show that our approach is able to improve several best known solutions of the literature. In fact, 76 solutions among 120 were improved. Moreover, HCPSO outperforms the compared methods in terms of quality of solutions in short time requirements. Also, the performance of the proposed approach is evaluated according to a real-world industrial problem.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.28-28
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• 2008

We have demonstrated the combinatorial synthesis of a variety of transparent conducting oxides using a combinatorial sputter system. The effects of a wide range of Nb or Zn doping rate on the optical and electrical properties of Indium-tin oxides (ITO) films were investigated. The Nb or Zn doped ITO films were fabricated on glass substrates, using combinatorial sputtering system which yields a linear composition spread of Nb or Zn concentration in ITO films in a controlled manner by co-sputtering two targets of ITO and $Nb_2O_5$ or ITO and ZnO. We have examined the work-function, resistivity, and optical properties of the Nb or Zn-doped ITO films. Furthermore, the effects of Hz plasma treatment on the physical properties of Ga or Zn doped ITO films synthesized by combinatorial sputter system were investigated.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1463-1466
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• 2007

Single phases of multi-component oxides films, ZrTiO4 and Ta2Zr6O17, could be synthesized by using the combinatorial approach through surface sol-gel route, coating the appropriate mole ratio of 100 mM zirconium butoxide, tantalum butoxide and titanium butoxide precursors on Pt/Ti/SiO2/Si (100) substrate, following pyrolysis at 450 oC, and annealing them at 770 oC. Both the films and bulks of ZrTiO4 and Ta2Zr6O17 showed very stable dielectric properties in temperature range, ?140 to 60 oC, and frequency range, 100 Hz to 1 MHz, promising their applications in wide range of temperatures and frequencies. The dielectric constants of the films were lower and a little more dependent on frequency than those of the bulks. The reduction of dielectric property in the film was mainly due to the interfacial effects that worked as series and parallel-connected capacitances toward the substantial film capacitance.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.66-68
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• 2000

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.811-815
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• 2004

Coumarin and its derivatives occur widely in nature. Many attempts were made for synthesis of various coumarin derivatives because of their interesting biological activities. In this study, solid phase synthetic approach of 3-(4-hydroxyphenyl)coumarin was achieved for combinatorial synthesis of substituted 3-phenylcoumarin analogues. Starting from 4-hydroxyphenylacetic acid methyl ester, release of 3-(4-hydroxypnehyl)coumarin from polymer support was accom-plished.