• Transactions of the Society of Information Storage Systems
• /
• v.10 no.2
• /
• pp.45-49
• /
• 2014

This study deals with obtaining the optimal shape of a patch antenna via the topology optimization method in order to enhance its radiation efficiency. The genetic algorithm scheme is proposed for the optimization process to satisfy the design objective. As a result, the optimal patch shape through the proposed process shows highly improved radiation efficiency and reduced scattered effects. Commercial package COMSOL and Matlab programming are employed for the entire optimization and analysis processes.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2003.11a
• /
• pp.428-431
• /
• 2003

In this paper, distances between elements are optimized for low sidelobe level (SLL) microstrip patch array using Genetic Algorithms. Genetic Algorithms are "global" numerical-optimization methods, it's advantages are very simple coding and fast optimization. This paper show how to optimize the maximum SLL using Genetic Algorithms. In the results, although mutual coupling is neglected, it's maximum SLL is 3.5 dB lower than Uniformly Spaced Array(distance=$0.5{\lambda}$).

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2003.11a
• /
• pp.432-436
• /
• 2003

This paper presents a broadband microstrip antenna design with four U slots on the ground plane by using of genetic algorithm. FDTD method is used as fitness function for antenna analysis, and length of rectangular patch, length of ground plane slot, distance from center point to feed point is used as optimization parameter for maximum bandwidth and minimum size. The measurement result of implemented antenna present bandwidth of 15.63 % and peak gain of 3.61 dBi in the 2.445 GHz, and antenna has a reduced patch size of 54.8 % compare with normal microstrip antenna.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.207-210
• /
• 1999

In this paper, aperture coupled microstrip antenna which has a larger bandwidth was designed using genetic algorithms. The genetic algorithms encodes each parameters which are the width, length of patch and the width, length of slot, into binary sequences, called a gen. Genetic algorithms searches a optimal gen to design a larger bandwidth. Simulation results are compared with Pozar's results.

• Korean Journal of Plant Resources
• /
• v.25 no.4
• /
• pp.407-415
• /
• 2012

Pinus pumila, which occurs in the northeast Asia, is found limitedly in Daecheongbong area of Mt. Seorak in the South Korea. This population was chosen to study spatial pattern, genetic diversity and spatial genetic structure. There were 48 polymorphic and 30 monomorphic I-SSR markers. A total of 65 individuals which distributed in the study site (40 m ${\times}$ 70 m) showed weakly aggregate distribution (Aggregate Index = 0.871). A total of 40 genets were observed from 65 individuals through I-SSR genotype comparison. Proportion of distinguishable genotype (G/N), genotype diversity (D) and genotype evenness (E) were 61.5%, 0.977 and 0.909, respectively. In spite of the small number and the limited distribution, Shannon's diversity index (I = 0.567) was relatively high as compared with those of other plant species. Spatial autocorrelation using Tanimoto's distance showed that the genetic patch was established within 12 m. Based on Mantel tests, there was relatively low correlation between genetic distance and geographic distance. Therefore, it seems the P. pumila population was formed by many parent trees in early stage. For ex situ genetic conservation of P. pumila, the sampling strategy is efficient at least above 12 m between individual trees.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.2
• /
• pp.194-198
• /
• 2004

This paper presents a broadband compact microstrip antenna design with four U slots on the ground plane by using of genetic algorithm. FDTD method is used as fitness function for antenna analysis, and length of rectangular patch, length of ground plane slot, distance from center point to feed point is used as optimization parameter for maximum bandwidth and minimum size. The measurement result of implemented antenna present 10 dB bandwidth of 15.63 ％ and peak gain of 3.61 dBi in the 2.445 GHz, and antenna has a reduced patch size of 54.8 ％ compare with normal microstrip antenna.

• Smart Structures and Systems
• /
• v.12 no.5
• /
• pp.523-545
• /
• 2013

Piezoelectric and dielectric behaviors of a piezoceramic patch adhesively centered on a carbon composite plate are identified using a robust multi-objective optimization procedure. For this purpose, the patch piezoelectric stress coupling and blocked dielectric constants are automatically evaluated for a wide frequency range and for the different identifiable behaviors. Latters' symmetry conditions are coded in the design plans serving for response surface methodology-based sensitivity analysis and meta-modeling. The identified constants result from the measured and computed open-circuit frequencies deviations minimization by a genetic algorithm that uses meta-model estimated frequencies. Present investigations show that the bonded piezoceramic patch has effective three-dimensional (3D) orthotropic piezoelectric and dielectric behaviors. Besides, the sensitivity analysis indicates that four constants, from eight, dominate the 3D orthotropic behavior, and that the analyses can be reduced to the electromechanically coupled modes only; therefore, in this case, and if only the dominated parameters are optimized while the others keep their nominal values, the resulting piezoelectric and dielectric behaviors are found to be transverse-isotropic. These results can help designing piezoceramics smart composites for various applications like noise, vibration, shape, and health control.

• Journal of Korean Society of Forest Science
• /
• v.105 no.3
• /
• pp.309-314
• /
• 2016

A locally adapted plant population under harsh environmental changes might survive for a long generation through maintaining proper level of genetic diversity. When it happens losing the genetic diversity too much fast, the population could be declining and probably become extinct. An isolated small population of Populus davidiana was investigated to study out the genetic diversity and the fine-scale spatial genetic structure. The estimated number of adult trees in the population of Mt. Worak, South Korea, was 350 in the total area of $14,000m^2$. The number of adults in a study plot ($70m{\times}70m$) was 123. The average age was 16-year-old and a 32-year-old tree was the oldest. The distribution of individuals was slightly aggregated in the plot. Sixty-one among the 123 individuals were randomly sampled to estimate genetic variation using AFLP markers. One hundred fifty-one (77%) of total 196 amplicons were polymorphic from six AFLP primer combinations. The average number of loci per primer combination was 32.7 (S.D.=7.2). Expected heterozygosity ($H_e$) and Shannon's diversity index (S.I.) were 0.154 and 0.254, respectively. These values were extremely lower than those of other P. davidiana populations in South Korea. Genetic patchiness was showed within 21 meters by spatial autocorrelation analysis and the isolated small size of population might be mainly attributed to the formation of such small patch size.

• Biomedical Science Letters
• /
• v.11 no.2
• /
• pp.103-108
• /
• 2005

2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.415-419
• /
• 2003

One strain was isolated from wilted chestnut tree and identified as Helicosporium nizamabadense. Also, the strain was evaluated for biocontrol potentials against phytopathogens. Autoclaved fraction of the isolate also showed complete growth inhibition of the turfgrass large patch pathogen, Rhizoctonia. solani AG2-2 and plant pathogen, Botrytis cinerea. Culture extracts of Helicosporium nizamabadense were purified by Thin Layer Chromatography. The several fractions were analyzed by GC-MS, and NMR etc. Antifungal activities were presumably showed more than 5 fractions against the pathogens. Among them, the most effective antifungal fraction was identified as 2-Methylresocinol using GC-MS, and NMR. These results suggest that the 2-Methylresocinol may be useful for biochemicals.