• Polymer(Korea)
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• v.25 no.1
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• pp.98-107
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• 2001

Dielectric properties and shape memory characteristics of SBS composites filled with carbon black as conductive filler and (Ba,Ca)$(Sn,Ti)O_3$ or $SrTiO_3$ as dielectrics were investigated for the development of phantom model. SBS/carbon black composite showed an increment of complex dielectric constant with increasing the content of carbon black and the frequency dependence that the dielectric constant decreases with the frequency. The complex dielectric constant and the conductivity of SBS/carbon black/dielectrics composites increased with the increase of dielectrics and the characteristics of the frequency dependence also occurred by the effect of carbon black. Phantom materials with the dielectric properties and the conductivity corresponding to human tissues for the measurement of specific absorption rate(SAR) within the frequency range of current mobile phones(775MHz~2GHz) could be developed by adjusting the composition ratios of carbon black, dielectrics and SBS and by controlling the characteristic of frequency dependence of composite. From thermomechanical cycling test good shape recoverability could be obtained in SBS composite even though the residual strain was increased by the effect of filler.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.2
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• pp.152-162
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• 2013

The physico-chemical characteristics and nanostructure of the aerosol samples from a coal-fired power plant, a charcoal kiln and diesel vehicles were investigated with focusing on black carbon (BC). Aerosols from the coal-fired power plant were mostly comprised of mineral ash spheres which are heterogeneously mixed. The main components of the aerosols from coal-fired power plant were calcium compounds, iron oxide, alumino-silicate without BC. The typical combustion-generated BC which shows the shape of bunch of grapes with 20~50 nm particles which were detected in aerosol particles from diesel vehicles. The nanostructure of each BC particle shows the shape of concentric circles which is comprised of closely-packed graphene layers. Aerosols from charcoal kiln were likely condensed organic carbon generated from the low-temperature combustion process.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.86.2-86.2
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• 2014

We present a new ray-tracing code, "Odyssey", for the Kerr spacetime accelerated by the Graphics Processing Unit (GPU). Taking advantage of the ability of nVidia graphic cards to evaluate trajectories of a large amount of photon simultaneously, the code is two orders of magnitude as fast as the previous CPU-based code corresponding to the speed of few nanoseconds per photon per time step. In the light of the Graphic User Interface (GUI) powered by the GPU-enhanced 2D/3D displaying technique, DirectX, it is feasible for users to manipulate diverse results such as rotating and zooming in/out the trajectories of photon instantly near the black hole. Thus the Odyssey can serve as a tool not only for scientific but also for the educational purpose. We discuss possible applications in detail in light of several results such as the shape of the silhouette of a black hole, the shape of a hot spot orbiting a black hole, and 3D photon trajectories.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.30-32
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• 2009

In this study, $CuInS_2$ powders have been synthesized using polyol process of a mixture of copper nitrate, indium nitrate, and thiourea with various stoichiometric molar ratios in ethylene glycol at 196$^{\circ}C$. As boiling time goes by, the color of metal ion mixed solutions were changed transparent green to dark green and finally fumed to black by reduction of $OH^-$ radicals. The prepared powders were fully characterized by SEM, XRD and UV-Vis. The particle shape of black colored powders showed sphere with about 30 nm in particle size compared to those with dark green colored powders showed irregular shape with about 1 ${\mu}m$ in particle size. The XRD results showed highly crystallized $CuInS_2$. The UV-Vis spectra showed broad shoulder at 430 and 780 nm corresponding to 2.78 and 1.58 eV for the dark green colored one and black colored one, respectively.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.43-48
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• 2016

In this paper, we propose a traffic light detection and recognition (TLDR) algorithm in the daytime. The proposed algorithm utilizes the color and shape information for the TLDR. At first, a traffic light is detected and recognized based on its shape information. Then, the color range of the detected traffic light is investigated in HSV color space. The input data of the proposed TLDR algorithm is the color image captured using the black box camera during driving. Our simulations demonstrate that the proposed algorithm can achieve a high detection and recognition performance for the images including traffic lights.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.42.2-42.2
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• 2014

We present high-resolution optical spectra of newly selected candidates of intermediate-mass black holes. The sample was selected based on the variability and spectral shape in X-ray. The spectra was taken with Magellan 6.5 m Clay Telescope and cover the rest-frame region 3500-10000A. The high spectral resolution (R~4000) of the spectrum allows us to estimate BH masses of the sources. Interestingly, the majority of the sample appears to have broad emission lines. Using this dataset, we will estimate the BH masses and Eddington ratio in order to understand their physical properties.

• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.585-601
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• 2004

A general study of domestic black sandstone and black shale quarries has not been made. For this reason it is difficult to know how the matter really stands. The objectives of this study are to achieve systematical and scientific study of the distribution, occurrences and rock quality of black sandstone and black shale resources exploited in existing quarries in the Boryeong area. The black sandstone bed survey was made from 54 mine claims on 4 sheets. In the area, 140 black sandstone and 22 black shale quarries were ascertained in 37 mine claims. The general development information data from that existing quarries were collected and synthesized. Among these black sandstone quarries for gravestones, monuments and black shale quarries for inkstone are in operation. Most of the black sandstone quarries were closed throughout the Gaewhari, Suburi, Seongjuri district in the investigated area even though these quarries had played a prominent part in the production of black sandstone. In view of commercial dimension stones, raw materials from black sandstone are classified as corestone and fresh rock body according to the characteristics of their occurrences and shape. Black sandstone beds are characteristically well-jointed and are particularly subdivided into cubic or quadrangular blocks in 3 joint sets. The colors of these black sandstones show medium dark $gray\~grayish$ black judging from the Rock Color Chart. The black sandstone beds which are intercalated in the Amisan, Jogeri, Baegunsa, Seongjuri Formations of the Daedong Supergroup are about $1\~10\;m$ in thickness.

• Applied Microscopy
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• v.40 no.3
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• pp.169-176
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• 2010

Black molly (Poecilia sphenops) and sailfin molly (Poecilia latipinna) are a teleost belonging to Poeciliidae. The spermatogenesis between two species were investigated by light and electron microscope. The whitish testes of both black molly and sailfin molly were located between intestine and air bladder. The size of testis was major axis 7 mm, minor axis 2 mm. The testis contained numerous testicular cysts. In both black molly and sailfin, primary spermatocytes were comparatively large ellipsoidal, and mitochondria showed a marked development. The secondary spermatocyte was smaller than that of primary spermatocyte, highly condensed according to their development. The nucleus with electron-dense was round shape and flagella started to be formed. In spermiogenesis, chromatin was more condensed. The mitochondria were rearranged along the tail. The number of mitochondria was 2 to 4 in cross section and 8 to 10 in longitudinal section. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins. In conclusion, spermatogenesis and sperm morphologies of these two species were same. These morphological similarity seems to be an indication of the Poeciliidae.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1648-1651
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• 2007

The goal of this paper is to introduce two methods to determine a model for the accelerated factor equation for pneumatic cylinder according to the Black equation shape. The loads consist of working pressure and temperature and we adjust these two parameters to reduce the test time but keeping the true behavior of deterioration. The first part will introduce a method using accelerated factor coming from experimental results to determine the coefficient of the Black equation by the method of the least square theory. The second part will introduce another method based on various conditions of test with the assumption that the effect of temperature and the effect of pressure on the life of pneumatic cylinder are independent. In these two cases, the results are the unknown coefficients of the Black equation.

• Korean Journal of Crystallography
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• v.7 no.2
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• pp.133-146
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• 1996

Morphology and infrared absorbing characteristics of Pt-black prepared by electroplating have been investigated with XRD, SEM, and IR spectrophotometer. The Pt later was coated on Au-coated alumina/glass substrates for 1-5 min at pH 1.0-1.5, where a solution of platinum chloride and lead acetate was used as the electrolyte. At the electrical current density of 20-50 mA/㎠, the Pt-black showed a dendritic growth which was characterized by a "tree" shape. Absorptivity of above 90% at IR radiation of 10 m was observed for the Pt absorbing layer with an area density of ≥1.3mg/㎠.