• Elastomers and Composites
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• v.6 no.2
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• pp.47-63
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• 1971

We have studied the blending effects of Diene 33R and styrenebutadiene rubber at various blending ratios of 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black HAF and ISAF at various compounding ratios of 55 PHR, 65 PHR, 75 PHR for tyre tread rubber. As the results, it was found that ; 1. For tyre tread rubber, when the blending ratio, Diene NF 35R/SBR 1778, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 65 PHR. The compounding of ISAF made better result than that of HAF for abrasion quantity, tearing strength, and tensile strength. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved. And as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to SBR than to Diene Rubber. 5. It is a shortage that elongation revealed low price.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.524-526
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• 2021

As the video wall controller market is growing rapidly, issues that have not been addressed so far are raised. One of them is a phenomenon in which a black screen is displayed on a multi-screen. Black screen is displayed due to an error in the video being displayed in the video wall controller. Human intervention is inevitable to recognize and solve the black screen. However, it is impossible for the operator to monitor the multi-screen 24 hours a day. In this paper, we propose a model that detects the black screen being displayed on the video wall controller. We propose a CNN based architecture to detect a black screen.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.63-73
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• 2023

This study explores modern portfolio theory by integrating the Black-Litterman portfolio with time-series clustering, specificially emphasizing K-shape clustering methodology. K-shape clustering enables grouping time-series data effectively, enhancing the ability to plan and manage investments in stock markets when combined with the Black-Litterman portfolio. Based on the patterns of stock markets, the objective is to understand the relationship between past market data and planning future investment strategies through backtesting. Additionally, by examining diverse learning and investment periods, it is identified optimal strategies to boost portfolio returns while efficiently managing associated risks. For comparative analysis, traditional Markowitz portfolio is also assessed in conjunction with clustering techniques utilizing K-Means and K-Means with Dynamic Time Warping. It is suggested that the combination of K-shape and the Black-Litterman model significantly enhances portfolio optimization in the stock market, providing valuable insights for making stable portfolio investment decisions. The achieved sharpe ratio of 0.722 indicates a significantly higher performance when compared to other benchmarks, underlining the effectiveness of the K-shape and Black-Litterman integration in portfolio optimization.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.54.2-54.2
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• 2008

• Toxicological Research
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• v.29 no.2
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• pp.121-127
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• 2013

Nanotoxicological research has shown toxicity of nanomaterials to be inversely related to particle size. However, the contribution of agglomeration to the toxicity of nanomaterials has not been sufficiently studied, although it is known that agglomeration is associated with increased nanomaterial size. In this study, we prepared aerosols of nano-sized carbon black by 2 different ways to verify the effects of agglomeration on the toxicity and deposition of nano-sized carbon black. The 2 methods of preparation included the carbon black dispersion method that facilitated clustering without sonication and the carbon black dispersion method involving sonication to achieve scattering and deagglomeration. Male Sprague-Dawley rats were exposed to carbon black aerosols 6 hr a day for 3 days or for 2 weeks. The median mass aerodynamic diameter of carbon black aerosols averaged $2.08{\mu}m$ (for aerosol prepared without sonication; group N) and $1.79{\mu}m$ (for aerosol prepared without sonication; group S). The average concentration of carbon black during the exposure period for group N and group S was $13.08{\pm}3.18mg/m^3$ and $13.67{\pm}3.54mg/m^3$, respectively, in the 3-day experiment. The average concentration during the 2-week experiment was $9.83{\pm}3.42mg/m^3$ and $9.08{\pm}4.49mg/m^3$ for group N and group S, respectively. The amount of carbon black deposition in the lungs was significantly higher in group S than in group N in both 3-day and 2-week experiments. The number of total cells, macrophages and polymorphonuclear leukocytes in the bronchoalveolar lavage (BAL) fluid, and the number of total white blood cells and neutrophils in the blood in the 2-week experiment were significantly higher in group S than in normal control. However, differences were not found in the inflammatory cytokine levels (IL-$1{\beta}$, TNF-${\alpha}$, IL-6, etc.) and protein indicators of cell damage (albumin and lactate dehydrogenase) in the BAL fluid of both group N and group S as compared to the normal control. In conclusion, carbon black aerosol generated by sonication possesses smaller nanoparticles that are deposited to a greater extent in the lungs than is aerosol formulated without sonication. Additionally, rats were narrowly more affected when exposed to carbon black aerosol generated by sonication as compared to that produced without sonication.

• Journal of Conservation Science
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• v.33 no.6
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• pp.417-429
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• 2017

This study aimed at the identification of the black coating materials on the pottery surface and manufacturing technique of black burnished pottery excavated from the Pungnaptoseong, Seoul, which is estimated to be royal fortress of Beakje. According to observation of black coated surface and raw materials, potteries can be divided into two groups. The first group potteries have black inner and black surface with well-selected particles. Second group potteries are black in surface only with unevenly selected particles. Each group seems to represent different manufacturing technique in clay selection, color development timing and method. The black burnished pottery contains high values of CaO, $P_2O_5$, L.O.I. and lower content of $Fe_2O_3$ compared with gray pottery excavated from the same site, which indicates plant ashes were used for coloring the surface of pottery in black. According to the result of SEM-EDS mapping of black burnished pottery, carbon was concentrated on pottery surface, while iron was concentrated on the surface of the gray pottery. Based on XRD analysis, firing temperature of the black burnished potteries were fired low temperature range at 700 to $900^{\circ}C$, and that of the gray potteries ranged from $900^{\circ}C$ to $1000^{\circ}C$.

• The Southeast Asian review
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• v.21 no.2
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• pp.329-358
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• 2011

The pottery and porcelain of Myanmar is very various such as Celadon, Black glazed large Jar and White galzed Jar painted Green Colour. In these Myanmarese Ceramics, Black glazed large Jar is very important to understand the Character and Role of Myanmar Ceramics. The description on the Black glazed large Jar of Myanmar is seen in several Books such as a travel essay of Ibun Battuta, Duarte Barbosa, The book of Duarte Barbosa: A Account of the Contries Bordering on the Indian Ocean and their Inhabitants, Jan Huygen van Linschoten, Volker, T., Porcelain and the Dutch East India Company These descriptions on the Black glazed Jar in these Books are important evidence to discovery the existence of it and its Types and Price and Use. The appearance of Black glazed Jar of Myanmar is considered in the Middle of 14C with the description of the Book of Ibn Battuta. Furthermore, Excavated from the Shipwreck of China in the Sinan, Chellanamdo, it is certain that the Black glazed large Jar was already existed in the early of 14C. And it was considered that the Shipwreck of China in the Sinan, Chellanamdo was started from Ninbo(寧波) of China to the destination of Japan with the Inscrition made Bamboo. So we know that The route of $Ninbo{\rightarrow}Korea{\rightarrow}Japan$ is very important in the Trade Ceramics of East Asia in 14C. And The size of Black glazed Jar has 3 types, Large, Middle and Small. The large type is used as a Tools for Water and Oil. The small type is the personal bottle for drinking. The Price of Black glazed Jar of Myanmar was changed as times go by. The price of the late of 16C and the early of 17C is 30 prolin and the late of 17C is 8 Prolin. The price of the Black glazed Jar of Myanmar in the late of 16C and the early of 17C is estimated 3 times for the price of the late of 17C. and This change of the price of Myanmarese Black Glazed Jar is decided on the Demand and Supply. and the Black glazed Jar of Myanmar was mainly used for the tools for Morpin in the year of 1620 and for Salt and Sugar in the year of 1640 and for Water and Oil in the late of 17C.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1100-1105
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• 1997

The verial black stripe is one of the defects in a chrge-coupled device(CCD). Vertical black stripes are caused by some signal chrges which fail to transport form the vertical CCD region to the horizontal one. The defective transport of signal charges orignates in the potential barrier with the narrow width effects in the verti-cal-horizintal interface stuccture. The vertical black stripes show up when the charge transfer dfficiency is less than 99.2% under the low illumination condition. In this research, we designed and developed a new vertical-horizontal interface structre of a delta type, thus marking it possible to eliminate the vertical black stripes.

• Journal of the Korea Furniture Society
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• v.22 no.1
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• pp.13-17
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• 2011

Recently, interest in indoor air quality is increasing. Especially, radon radioactivity among the indoor air is a well-known risk factor for lung cancer because of ionizing radiation in the form of ${\alpha}$-particles. This study was carried out to investigate effect of black charcoal and activated carbon for reduction of radon radiation that emitted from building materials. Black charcoal and activated carbon were used as a barrier which was against the infiltration of radon. The source of radon was gypsum board. Two types of charcoal barrier were powder- and board-type with 5 mm, 10 mm thickness respectively. The method for this determination is evaluated radon concentration in chamber. The measurements were performed with radon detector, SARAD3120. Results of this study are as following: Black charcoal and activated carbon confirmed the highly efficient barrier. Radon concentration was reduced from 72% to 85% as compared the control chamber. Radon reduction capability, however, was no difference as barrier's types. Results obtained in ventilation condition, radon concentration shows 5.93 pCi/L on average in the closed condition and shows 2.69 pCi/L in the opened condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2511-2515
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• 2013

Carbon black from pyrolysis of waste tires was used to modify and improve the fatigue properties and low temperature cracking of asphalt binder. 0%, 5%, 10%, 15% and 20% of pyrolyzed carbon black was mixed. Couple of laboratory tests, such as dynamic shear rheometer test and bending beam rheometer test, were carried out. The use of pyrolyzed carbon black decreased the fatigue at room temperature and improved the resistance of low temperature cracking up to $-12^{\circ}C$, but, was off the criteria at $-18^{\circ}C$.