• Polymer(Korea)
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• v.32 no.1
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• pp.38-42
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• 2008

Ultrathin films were coated on low density Polyethylene (LDPE) food packaging films by plasma polymerization of methane, acetylene, hexamethyldisiloxane (HMDSO), and HMDSO+oxygen to improve the barrier property of the LDPE films. The film coated in HMDSO +oxygen (flow rate: 0.6+ 9.0 SCCM) plasma at 40 W for 10 min showed the highest improvement in the barrier property against oxygen, reducing the permeability of oxygen as much as 18.6 times. The film coated in acetylene (flow rate 0.75 SCCM) plasma at 10 W for 10 min showed the highest improvement in the barrier property against carbon dioxide and moisture, reducing the permeability of carbon dioxide and moisture as much as 12.0 and 3.0 times, respectively. In addition, cherry tomato, cucumber, and mushroom (Flammulina velutipes) wrapped with the coated films were kept fresh $1.5{\sim}3.0$ times longer than those wrapped with an LDPE film.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.735-739
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• 2005

This paper presents a new system to estimate the head pose of human in interactive indoor environment that has dynamic illumination change and large working space. The main idea of this system is to suggest a new morphological feature for estimating head angle from stereo disparity map. When a disparity map is obtained from stereo camera, the matching confidence value can be derived by measurements of correlation of the stereo images. Applying a threshold to the confidence value, we also obtain the specific morphology of the disparity map. Therefore, we can obtain the morphological shape of disparity map. Through the analysis of this morphological property, the head pose can be estimated. It is simple and fast algorithm in comparison with other algorithm which apply facial template, 2D, 3D models and optical flow method. Our system can automatically segment and estimate head pose in a wide range of head motion without manual initialization like other optical flow system. As the result of experiments, we obtained the reliable head orientation data under the real-time performance.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.47-52
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• 2014

Oxidation stability and cold fuid property are considered as the most important factors for determining biodiesel quality. Among the fatty acids, monounsaturated fatty acid satisfy both oxidation stability and cold flow property of biodiesel quality standards. Microalgae with high monounsaturated fatty acid contents is have some benefit for producing to produce biodiesels with satisfying quality standards. In this study, monounsaturated fatty acid contents of a isolated microalga from Youngheung island was analyzed. Phaeodactylum tricornutum was isolated by streaking, and growth rate and fatty acid composition of the algae were investigated. Total FAME contents were consisted of 26% of saturated fatty acids, 43% of monounsaturated fatty acids, and 18% of polyunsaturated fatty acids. The contents of monounsaturated fatty acid were especially high in the Phaeodactylum species. This result implies that the FAMEs from P. tricornutum may contribute to improve the oxidation stability and cold flow property of biodiesel.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.188-191
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• 1993

Silicon flow sensor which can detect the magnitude and direction of two dimensional air flow was designed and fabricated by CMOS process and bulk micromachining technique. The flow sensor consists of three-layered dielectric diaphragm a heater at the center of the diaphragm and four thermopiles surrounding the heater at each side of diaphragm as sensing elements. This diaphragm structure contributes to improve the sensitivity due to excellent thermal isolation property of dielectric materials and its tiny thickness. The flow sensor has good axial symmetry to sense 2-D air flow with the optimized sensing position in the given structure. Measured sensitivity of our sensor is $18.7mV/(m/s)^{1/2}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.445-451
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• 2002

The refractory-lined pipe is used to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis for fluid catalytic cracking(FCC) unit piping design. The equivalent elastic modulus and density considering steel and refractory must be applied in the stress analysis of the system. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the parametric analysis is carried out to understand the characteristic of the material properties, and the stress analysis is performed with reactor, the part of FCC unit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.885-891
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• 2003

Effects of each acoustic property on absorption characteristics of polyester fiber materials has been studied in this paper. It would be impossible for us to measure effects of each acoustic property by experimental method since we cannot make sound-absorbing materials in which only one of the properties is changed. We have adopted a numerical prediction method to carry out parameter studies for each acoustic property. And to get a general behavior of acoustic performance of the materials, the numerical simulation has been repeated to several cases of different bulk density. Finally we have obtained frequency-dependent control factors in the absorption performance which gives us design capability of acoustic absorbing materials.

• Journal of the Korean Mathematical Society
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• v.59 no.2
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• pp.337-352
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• 2022

We consider the set of points with historic behavior (which is also called the irregular set) for continuous flows and suspension flows. In this paper under the hypothesis that (X_t)_t is a continuous flow on a d-dimensional Riemaniann closed manifold M (d ≥ 2) with gluing orbit property, we prove that the set of points with historic behavior in a compact and invariant subset ∆ of M is either empty or is a Baire residual subset on ∆. We also prove that the set of points with historic behavior of a suspension flows over a homeomorphism satisfyng the gluing orbit property is either empty or Baire residual and carries full topological entropy.

• Journal of Korea Technology Innovation Society
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• v.11 no.2
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• pp.241-263
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• 2008

Within any income approach, a discount rate is used to convert some projected free cash flow to its presented value. In case of valuing companies, the most frequently used discount rate is the weighted average cost of capital(WACC) at the aggregate level. But technology valuation is different to discounting aggregate corporate cash flow since it is concerned about individual Intellectual property. Therefore, blindly applying standard discount rate such as WACC in technology valuation is unlikely to lead to the right result. The primary focus of this paper is to establish the structure of discount rate for technology valuation and to suggest the method of estimation. To determine an appropriate discount rate for technology valuation, the level of technology risk, market risk and competitive risk should be included in the structure of discount rate. This paper suggests the build-up model which consists of three components as a expansion of the CAPM. It includes (1) a risk-free rate of return, (2) general market risk premium and beta and (3) intellectual property risk premium related to technology risk and specific target market risk. However, there is no specific check list for examining the intellectual property risk until now and no specific method for quantifying its risk into risk premium. This paper developed the 10 element to determine the level of the intellectual property risk and applied estimation function such as linear function, natural log function and exponential function to transform the level of risk into risk premium. The limitation of this paper is that the range of intellectual property risk premium is inferred based on the information of foreign and domestic valuation agency. Finally, this paper explored the development of an intellectual property discount rate for technology valuation and presented the method in order to quantify the intellectual property risk premium.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.61-64
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• 2003

In the field of automobile industry, suspension parts have been fabricated by the light metal part to substitute the steel part. For application light metal of suspension parts, mechanical property of high strength was performed. For anting semi-solid die casting of suspension part, die filling and solidification simulation have been carried out with Ostwald-de Waele rheological model. We designed the optimal die and secured injection condition as possible as laminar flow based on the result of computer simulation. Mechanical properties of knuckle part and heat treatment condition were investigated.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.45-50
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• 1998

This study is aimed for investigating the rheology property and fluidity of superplasticizer which is necessary using for high flowing concrete fluidity establishment. Therefore, this study is analysis the rheology property and fluidity by different according temperature and elapsed time. From the results, the fluidity and rheology value were different according temperature. Over 2$0^{\circ}C$, the flow value of A, B, C, D, E type is increased, according as the increase of temperature, but the flow value of F type is decreased.