• Korean Journal of Optics and Photonics
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• v.30 no.2
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• pp.67-73
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• 2019

In this paper, we investigated the sensing ability of an extraordinary optical transmission sensor, which is based on the diverse configurations of highly ordered structures. The diverse nanostructures of subwavelength hole array were designed to have different periods and lattice configurations of the array. To verify the sensing ability of the sensor, we measured the transmittance spectra of samples (n = 1.333, 1.363) for diverse configurations of substrates. The measured transmittance spectra of diverse materials with different refractive indices show that the sensitivity increased as the period of the structures increased. Also, improved sensing performance of the sensor was achieved for the square array, compared to the hexagonal array.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.9
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• pp.2770-2781
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• 1996

Longitudinal shear modulus of continuous fiber reinforced 2-phase composites is predicted by theoretical and numerical analysis methods. In this paper, circular, hexagonal and rectangular shapes of reinforced fiber are considered using unit cell concept. And fiber array is regular rectangular and hexagonal fiber arrangement. Longitudinal shear modulus is a function of fiber distribution pattern and fiber volume change. It is found that the rectangular array has a higher longitudinal shear modulus than the hexagonal one. Also, the rectangular fiber shape in lower fiber volume fraction and the circular fiber shape in higher fiber volume fraction show the higher longitudinal shear modulus. And it has been found that the theoretical and numerical predictions of the longitudinal shear modulus give a good agreement with the experimental data at lower fiber volume fraction. Both the distance and stress transfer between the fibers are discussed as the major determing factors.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3575-3580
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• 2011

This paper reports a methodology for preparing close-packed two dimensional gold nanoprism films and hexagonal nanoplate films at a hexane/water interface. By controlling the concentration of linker molecules in the hexane layer and the temperature of the colloid solution, highly ordered close-packed nanoplate arrays can be fabricated. These films were investigated to compare their corresponding surface enhanced Raman scattering (SERS) efficiencies. It was demonstrated that the Au nanoprism films resulted in a stronger SERS enhancement than the Au hexagonal nanoplate films. The difference in the SERS enhancement is attributed to the film array difference, demonstrating that Au nanoprism films have a higher line contact density than their Au hexagonal analogues.

• Tribology and Lubricants
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• v.25 no.1
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• pp.25-30
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• 2009

본 연구에서는 pin-on-disk 마찰 시험기를 통하여 Hexagonal 배열 $40{\mu}m$ Dimple 패턴의 효과를 실험하였다. 마찰 실험은 미끄럼 속도가 $0.06{\sim}0.34m/s$로 하였으며 마찰하중은 $20{\sim}100\;N$의 범위로 하였고, Dimple의 밀도는 $10{\sim}25%$의 범위로 제작하여 실험을 행하였다. 일반적으로 속도가 증가하고 하중이 감소할수록 마찰계수는 감소하는 경향을 나타내었으며, Dimple에 의한 마찰저감 효과는 속도가 $0.14{\sim}0.26m/s$의 범위에서 나타났다. $40{\mu}m$ Hexagonal 배열 Dimple 패턴의 마찰 특성에서는 밀도가 12.5%에서 가장 좋은 경향을 나타내었다.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.204-211
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• 1994

Micro array lens systems are designed for a faximile or copy machine. The array type is hexagonal. Diameter of a lens is 0.16 mm and the distance of the center of the nearest neighbor is 0.192 mm. The magnitude of the lens system is 1:1. Working distane is 10.55 mm and the spot size is less than 0.04 mm radius on axis and 0.20 mm off-axis in case of single layer system. Working distance is 7.90 mm and the spot size is less than 0.07 mm radius on axis and 0.09 mm radius off axis in case of double layer system. Performance of single layer micro array lens system and double layer micro array lens system are compared with the characteristics of the ray fans.y fans.

• Tribology and Lubricants
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• v.27 no.5
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• pp.264-268
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• 2011

In this study, we examined the friction characteristics of a dimple pattern on a carbon nitride coating. The study was conducted with a hexagonal array 40 ${\mu}m$ dimple pattern on a steel bearing containing a CNx coating. The area density of the dimple patterns were varied between 5% and 25%, the speed was varied from 0.06-0.26 m/s, and the load was varied between 20-100N. In general, we found that as the velocity increased, the friction coefficient increased. Furthermore, the friction coefficient was lowest at a load of 40N. The friction coefficient of the non-coated specimen was 0.025-0.15; on the other hand, the friction coefficient of the coated specimen was 0.002-0.02. Thus, we determined that the coated materials could reduce the friction coefficient by a factor of 7.5.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.995-1007
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• 2008

Studies on modeling the rainfall-runoff relationship which shows nonlinear trend strongly use artificial neural networks theory not only for the prediction but also for the characteristics analysis of the data used by pattern classification. For the pattern classification, the results from Self-Organizing Map (SOM) mention that the map size and array for the SOM training have significantly influenced on the SOM performance. Since there is no deterministic method or theoretical equation to determine the number of rows and columns for the map size, hexagonal array is generally used for the map array. Therefore, this study present a determination of the optimized map structure for the rainfall-runoff analysis in Naju station considering the map size and array simultaneously which can represent the classified characterization of rainfall-runoff relationship. The result showed that the map size of 20$\times$16 hexagonal array with 8-clustered patterns was selected as an appropriate map structure for rainfall-runoff analysis in Naju station.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.489-496
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• 2001

Two perforated plates are used to investigate local heat/mass transfer characteristics in an impingement/effusion cooling system. A naphthalene sublimation method is conducted to determine the local heat/mass transfer coefficients on the upward facing surface of the effusion plate. The two plates are placed in parallel position with gap distances of 1, 2, 4 and 6 times of effusion hole diameter. The effects of hole arrangements of the plates are studied for staggered, square, and hexagonal arrays. The experiments are conducted at Reynolds number of 10,000 based on the effusion hole diameter. The results show that the smaller hole size in the staggered array has the higher transfer coefficients on the stagnation region due to the formation of higher momentum flows through the impingement holes. In the square array, heat/mass transfer on the target plate is more uniform as the number of impingement holes increases. High and uniform heat/mass transfer coefficients are obtained in the hexagonal array.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.101-109
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• 2002

Two perforated plates are used to investigate local heat/mass transfer characteristics in an impingement/effusion cooling system. A naphthalene sublimation method is conducted to determine the local heat/mass transfer coefficients on the upward facing surface of the effusion plate. Two plates are placed in parallel position with gap distances of 1, 2, 4 and 6 times of effusion hole diameter. The effects of hole arrangements of the plates are studied fur staggered, square, and hexagonal arrays. The experiments are conducted at Reynolds number of 10,000 based on the effusion hole diameter. The results show that the smaller hole size in the staggered array has the higher transfer coefficients on the stagnation region due to the formation of higher momentum flows through the impingement holes. In the square array, heat/mass transfer on the target plate is more uniform as the number of impingement holes increases. High and uniform heat/mass transfer coefficients are obtained for the hexagonal array.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.9 s.100
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• pp.862-871
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• 2005

In this paper, the modified design equation of shielding effectiveness was presented to predict more accurately the shielding effectiveness of honeycomb structure with hexagonal waveguide. The design equation of shielding effectiveness in honeycomb was represented from adding shielding effectiveness of single lattice to shielding effectiveness of infinite array of single lattice. This paper proposed the generalized design equation of shielding effectiveness by analyzing basis lattice of hexagonal waveguide which composes honeycomb structure and infinite array structure of basis lattice. To provide the validity of the modified design equation of shielding effectiveness in this paper, comparison with other available date using 3D EM commercial software is made.