This paper presents a systematic analysis of the signed barycentric coordinate concerning a triangle and its application to the smooth color shading of a square containing a triangle. The primary purpose of this paper is to establish a unified theory of the barycentric coordinate, which is valid regardless of whether a given point is inside, outside, or on the boundary of the referenced triangle. First, the barycentric coordinate in a triangle is geometrically defined as the ratio of the signed areas of three sub-triangles. Second, the algebraic computation of three components of the barycentric coordinate is described, which facilitates the efficient calculation of the signed values of the three components. Third, based on the sign combination of the barycentric coordinate, 2-dimensional space is wholly divided into a total of 19 regions, and the decision table is provided to determine the region where a given point belongs. Fourth, as an application of the signed barycentric coordinate, the smooth shading of a square with an equilateral triangle inside is performed, along with the generation of repetitive color patterns with the left-right and top-bottom symmetry.

Carbon Fiber Reinforced Plastics (CFRP) is composed of carbon fiber and resin. Carbon fiber has superior strength and stiffness and is lighter than primary light metals. When CFRP is applied to structural parts, these general mechanical properties depend on the orientation of the carbon fiber. The mechanical properties of CFRP are obtained through material testing, such as applying tension or compression in different fiber directions. In this study, the physical properties of CFRP were acquired to investigate the impact characteristics of structural members to which CFRP with different layer structures was applied through impact tests and simulations, and based on this, an impact simulation was performed on circular structural members. Three failure criteria were applied to investigate the collapse behavior due to impact loading in the finite element model of the simulation. Moreover, the simulation results according to each failure criterion were compared and considered.

To determine the crystal growth mechanism of Alq3 OLED material, this study investigated the effect of surface charge induced by voltaic cells on the growth pattern of Alq3 single crystal. [C12mim][TFSI] was used as the ionic liquid, and the concentration of Alq3 was fixed at 1mol%. The electrode was made of ITO substrate and stainless steel. In order to measure the potential difference between the two electrodes, two environments with the addition of 12g of pure [C12mim][TFSI] and Alq3 were measured. After the measurement, an environment was formed to cause a spontaneous redox reaction based on Volta's cell principle and crystallized by isothermal heat treatment at 100℃. Over time FE-SEM, EDS, and XRD analysis confirmed crystal shape and electronic and optical properties.

In manufacturing enzyme electrodes, mineral oil is efficiently used as a carbon powder binder. To put the carbon paste electrode into practical use, it is necessary to secure the mechanical hardness of the electrode material after it is manufactured. Although mineral oil has sound formability, it is not easy to obtain mechanical strength. To solve this issue, an enzyme electrode was manufactured using butyl rubber dissolved in toluene as a binder for carbon powder. These electrodes' quantitative and qualitative behaviors were observed by measuring their limiting current, symmetry factor, mass transfer coefficient, mass transfer resistance, exchange current density, and charge capacity. The experimental results suggested that butyl rubber is a suitable binder for carbon powder.

Since bamboo leaves contain various polyphenols, including phenolic acids, they have recently been used for tea extract products. To evaluate the quality of tea extract, rapid estimation of the antioxidant activity of tea extract is essential. This study proposed Fourier Transform Infrared Spectroscopy (FT-NIR) combined with partial least squares (PLS) regression to estimate antioxidant activities as a new quality control technique measure. Total polyphenol content (TPC), DPPH radical scavenging activity (DPPH), and ABTS radical scavenging (ABTS) activity were measured as antioxidant activity potential. To increase the accuracy of the PLS model, the NIR spectrum is preprocessed using the standard normal variate (SNV) and multiplicative scattering correction (MSC) methods. The best calibration model accuracy is obtained using the MSC preprocessed spectrum. The RC2 values of the TPC, DPPH, and ABTS were 0.6789, 0.7973, and 0.7551, respectively. These results of the MSC preprocessed spectrum indicated that the antioxidant activities of bamboo leave extracts could be estimated using PLS models and FT-NIR detection.

Bamboo extract contains large amounts of polyphenols and flavone glycosides as natural antioxidants. It is known that the types of polyphenols and fatty acids contained in each type of bamboo are different, and the antioxidant activity is also different. This study analyzed the antioxidant activity and functional component analysis of domestic bamboo (Phyllostachys pubescens and Sasa coreana Nakai) leaf extracts. An oil extract was prepared from Phyllostachys pubescens and Sasa coreana Nakai using an organic solvent (n-hexane, chloroform:methanol). Antioxidant activity, total polyphenol content (TPC), and total flavonoid content (TFC) of the prepared oil extract were measured. Gas chromatography-mass spectrometry (GC-MS) analysis was performed to confirm the components contained in the oil extract. As a result of the experiment, it was confirmed that the yield of chloroform:methanol was the highest, and the yield of the hexane extract was meager. It was confirmed that the DPPH and ABTS activities of the SC-C extract were the highest, while those of the IC50 were 1,064.21 μg/mL and 437.35 μg/mL, respectively. TPC and TFC were also confirmed to have the highest SC-C extract contents, which were 45.27 and 74.32, respectively. As a result of GC/MS analysis, it was confirmed that the types contained differed depending on the extracted solvent. This study confirmed the possibility of using bamboo leaf oil extract as a cosmetic material.

Torreya nucifera grows wild in Korea, Japan, China, and Southern Asia. So far, various studies have been conducted on the fruit of birch trees, but studies on leaves and branches are insignificant. In this study, antioxidative activity (DPPH free radical, ABTS radical scavenging activity), total polyphenol content, and total flavonoid content of hydrophobic components were measured in leaves and branches of T. nucifera. In addition, GC/MS analysis was performed to measure the content of hydrophobic substances contained in the organic solvent extracts of T. nucifera leaves and branches. As a result of the analysis, a total of 21 components were analyzed, and 3 principal components were identified as 1,3-di-tert-butylbenzene, 2,4-di-tert-butylphenol, and α-cadinold. The organic solvent extracts of T. nucifera leaf and branch extracts contain many various substances, including a phenolic structure suitable for antioxidants. Therefore, extracts of T. nucifera leaves and branches would be suitable as skin cosmetic and hair cosmetic materials.

Aurea Helianthus is a plant originating from China and contains a large amount of various pharmacological components and high molecular weight mucilage. This study evaluated Aurea Helianthus leaf extract's antioxidant activity and hair improvement effect. The IC50 value of DPPH radical activity of the ethanol 70% extract of Aurea Helianthus leaf was 613.08 μg/mL, and the IC50 value of ABTS radical activity was 191.73 μg/mL. When 1-5% ethanol extract from Aurea Helianthus leaf was used to treat damaged hair, changes in tensile strength and hair thickness were observed in a concentration-dependent manner. In addition, SEM measurement was performed using an optical microscope, and the experimental group treated with the Aurea Helianthus leaf extract showed the effect of protecting the damaged cuticles in a concentration-dependent manner compared to the control group. In conclusion, Aurea Helianthus leaf extract is effective for damaged hair and is judged to be a suitable raw material for hair cosmetics.