• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.6
• /
• pp.610-616
• /
• 2010

In this paper, particle swarm optimization(PSO) is applied for the design of frequency selective surface based artificial magnetic conductor. An equivalent circuit model for this artificial magnetic conductor(AMC) with Jerusalem Cross arrays was derived and then PSO was applied for obtaining the optimized geometrical parameters with desired resonant frequency. The resonant frequency and the reflection phase characteristics from the optimization were compared to the results from commercial software for verifying the validity of this paper. The procedure presented in this paper can be applied to design the AMC with different frequency selective surface and also can be used for the design of microwave circuits like the AMC ground planes.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.2
• /
• pp.123-130
• /
• 2013

In this paper, the delamination and failures in frequency selected surface(FSS) caused by residual stresses in the FSS embedded hybrid composites due to the difference between the coefficients of thermal expansion of components and the transmission characteristic changes due to deformation of FSS patterns by residual stresses were studied. FSS may have different electromagnetic characteristics depending on the type of element, design variables, and arrangement. Design variables of dipole FSS were determined using PSO(Particle Swarm Optimization) to obtain the transmission characteristic for the target resonant frequency. Subsequently, the design variables of other types of N-pole(tripole, cross dipole, and Jerusalem cross) were determined based on the dimensions of the dipole for the comparisons of residual stresses of FSS embedded composite structures and transmission characteristics. In addition, effects of FSS pattern, and stacking sequence of composite laminates were considered.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.6
• /
• pp.11-20
• /
• 2019

A Radome protects the radar from the external environment, and as a part of the stealth technology, a frequency-selective surface (FSS) was applied to the radome. Our study investigates the changes in the electrical transmission characteristics of the missile's FSS radome due to aerodynamic heating in various flight scenarios. Accordingly, we designed a FSS radome with a Jerusalem-cross(JSC) geometry and referred the missile flight scenario in the precedent research. Subsequently, electrical transmission characteristics affected by aerodynamic heating were numerically analyzed over time according to the position of radome. As a result, we found that the average transmission value maximally varies -14.3 dB compared to the initial bandwidth owing to changes in electrical transmission characteristics in flight scenarios.

• Membrane and Water Treatment
• /
• v.2 no.2
• /
• pp.105-119
• /
• 2011

This study presents the tests of an Immersed Membrane BioReactor (IMBR) equipped with a draft tube and focuses on the influence of hydrodynamic conditions on membrane fouling in a pilot-scale using a hollow fiber membrane module of ZW-10 under ambient conditions. In this system, the cross-flow velocities across the membrane surface were induced by a cylindrical draft-tube. The relationship between cross-flow velocity and aeration strength and the influence of the cross-flow on fouling rate (under various hydrodynamic conditions) were investigated using Multi-Dimension Scaling (MDS) analysis. MDS technique is especially suitable for samples with many variables and has relatively few observations, as the data about Membrane Bio-Reactor (MBR) often is. Observations and variables are analyzed simultaneously. According to the results, a specialized form of MDS, CoPlot enables presentation of the results in a two dimensional space and when plotting variables ratio (output/input) rather than original data the efficient units can be visualized clearly. The results indicate that: (i) aeration plays an important role in IMBR performance; (ii) implementing the MDS approach with reference to the variables ratio is consequently useful to characterize performance changes for data classification.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.30 no.4
• /
• pp.300-306
• /
• 2019

Transmission cross section(TCS) is described analytically as $2G{\lambda}^2/4{\pi}$ irrespective of the aperture shapes for various transmission resonant apertures, such as small ridged circular or H-shaped, U-shaped, or Jerusalem cross-shaped apertures in an infinite thin conducting plane. The proposed expression is validated by comparison with the numerical results obtained from the method of moments(MOM). The TCS characteristics of the transmission resonant cavity structure in a thick conducting plane are also studied and the equivalence between the two small aperture structures is reported from the viewpoint of transmission efficiency.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.1
• /
• pp.67-76
• /
• 2009

The development of a variety of methods like AM1, PM3, PM5 and DFT now allows the calculation of atomic and molecular properties with high precision as well as the treatment of large molecules with predictive power. In this paper, these methods have been used to calculate a number of quantum chemical descriptors (like Klopman atomic softness in terms of $E_n^{\ddag}\;and\;E_m^{\ddag}$, chemical hardness, global softness, electronegativity, chemical potential, electrophilicity index, heat of formation, total energy etc.) for 75 alkanes to predict their boiling point values. The 3D modeling, geometry optimization and semiempirical & DFT calculations of all the alkanes have been made with the help of CAChe software. The calculated quantum chemical descriptors have been correlated with observed boiling point by using multiple linear regression (MLR) analysis. The predicted values of boiling point are very close to the observed values. The values of correlation coefficient ($r^2$) and cross validation coefficient ($r_{cv}^2$) also indicates the generated QSPR models are valuable and the comparison of all the methods indicate that the DFT method is most reliable while the addition of Klopman atomic softness $E_n^{\ddag}$ in DFT method improves the result and provides best correlation.

• Cross-Cultural Studies
• /
• v.37
• /
• pp.51-79
• /
• 2014

Seriously depressed by the failure in the first performance of his own drama ${\ll}$The Government Inspector${\gg}$, N. Gogol sought out a space, Italy, which is obviously a turning point for the writer. Here in Italy, the writer could be able to explore an essential foundation for the national identity as well as self-identification of Russian traditional culture, all of which have already been epitomized in the Renaissance period in Italy. The city Rome itself provided Gogol with its grandness and harmonious perfectness, influencing something 'spiritual being' upon the writer. The work under discussion, "Rome," is thus created through these literary circumstances. Though it is made under the different title as "Annuntiata" and it delivers a love story between lovers, the story lines gradually turned into a fiction about the city, Rome. In comparison with city Paris, Gogol himself presents a negative view of the French metropolitan, saying that it is nothing but a by-product of the 19th century civilization. Interestingly enough, Rome for Gogol is totally different; it is the place of sublimity, that is a locus of harmonious, holy, and eternal city. Likewise, this pattern can be said of another description on the two contradictory cities: Paris and Rome. Again, Gogol fully pictures the city Paris as centripetal and Rome as centrifugal, in which the main protagonist makes the reader indulge in his own world. Throughout the story the writer tells us a transformation experienced by his character, and the work ends with an open denouement. Like Jerusalem, Rome is the city of resurrection for Gogol. Yet, this kind of possibility of transformation in the story is exposed to the hero, and it arguably depends on the extent to which he explores the readiness for encountering of 'eternity' in this "eternal city."

• Cross-Cultural Studies
• /
• v.23
• /
• pp.167-189
• /
• 2011

In modern Spanish culture, there is not other cineaste who has explored the controversial topic of sexuality deeper and more reiterative ways than Pedro $Almod{\acute{o}}var$. In our opinion, $Educaci{\acute{o}}n$> fundamentally, is a metaphoric work about the corruption of the Catholicism during Francisco Franco regime in Spain. This movie is a brilliant and solid critic to the abuses suffered by a child in a religious school during the Franco regime. This movie is about the forbidden desire in Catholicism and the tragic end of a priest. Father Manolo sexually abused one of his students at the school; as a result, this student loses his sexual identity and ends up ruining his own life due to using drugs. Eventually he is revenged by his younger brother. On this movie, $Educaci{\acute{o}}n$>, Pedro $Almod{\acute{o}}var$ portrays a sentiment of anticlericalism and blasphemy against God and Jesus Christ through a story which contains homosexual scenes and direct quotations of biblical cites, such as the expulsion of the merchants and sellers out of the temple in Jerusalem in the Mathew gospel to insinuate Jesus'lack of charity and love to others. We conclude that Almodovar's description of the fallout of this priest, caused by his forbidden desire, is not only beyond anti-Catholicism but it can also be seen as an actual reflection of the cultural and sexual change in the European and, in particular, Spanish society.

• Journal of English Language & Literature
• /
• v.58 no.4
• /
• pp.723-752
• /
• 2012

Although his mythic poetry deals with the fall and resurrection of Albion as the origin of humankind, William Blake (1757-1827) simultaneously links it to the professionalization and unification of disciplinary knowledge itself. He particularly takes a great interest in the cross-referential relation of poetry to science. He argues for the communication of poetry and science on equal footing with each other without the former's prioritization over the latter, or vice versa. In his works Vala, or The Four Zoas (1797-1807) and Jerusalem: The Emanation of the Giant Albion (1804-1820), on which I focus in this essay, Blake's primary problematic is to display strong conflicts among different systems of knowledge. I approach this issue in light of the ideological clash of Newtonian thought, Romantic thought, and postmodern thought. In his poetry, Blake thematizes the very clashes of these different thought patterns. From the standpoint of Romantic thought, first of all, Blake problematizes Newtonian Enlightenment. He criticizes abstract universalization both in poetry and science, which Urizen, one of four Zoas, propagates. Protesting against Urizen's Newtonism, Los values "living form." Thus, Blake demonstrates, through this figure, that poetic imagination and scientific organicism are discursively communicative. Blake, however, also questions the network of Romantic science and Romantic poetry so as to suggest what current critics would call postmodern thought. Blakean postmodernism pursues the self-similarity of organic structure in science and poetry. Precisely, Blake sees polypus as a proliferation of organic body; he arranges four Zoas' self-repetitive stories in a non-linear way. Blake aspires for the conflicting coexistence of different thought patterns.