• ETRI Journal
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• 제28권6호
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• pp.745-760
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• 2006

In this paper, we particularly deal with no $F_p$-rational two-torsion elliptic curves, where $F_p$ is the prime field of the characteristic p. First we introduce a shift product-based polynomial transform. Then, we show that the parities of (#E - 1)/2 and (#E' - 1)/2 are reciprocal to each other, where #E and #E' are the orders of the two candidate curves obtained at the last step of complex multiplication (CM)-based algorithm. Based on this property, we propose a method to check the parity by using the shift product-based polynomial transform. For a 160 bits prime number as the characteristic, the proposed method carries out the parity check 25 or more times faster than the conventional checking method when 4 divides the characteristic minus 1. Finally, this paper shows that the proposed method can make CM-based algorithm that looks up a table of precomputed class polynomials more than 10 percent faster.

• 한국응용과학기술학회지
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• 제26권3호
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• pp.233-239
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• 2009

A reaction device raising a generation yield by efficiently removing water generated in an esterified reaction between diethylene glycol monoethyl ether and succinic acid with mixture of an azeotropic point was newly developed as a new product in development of more stabilized emulsifier with a semi-solid phase(cream) in an emulsified phase of interfacial activity. The bis-(diethylene glycol monoethyl ether succinate(hereinafter, called as BDGS) with a high yield of more than 95% was obtained. As this has a property containing amphoteric emulsified functions such as W/O type or O/W type, etc., and has a merit that can be used regardless of any emulsified phase, there is no need using other emulsified surfactant. therefore, as this has excellent skin wetability in the cosmetics industry, a product having a wider range in quality compatibility or cost saving, etc. as a humectant has been developed.

• International Journal of Reliability and Applications
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• 제2권4호
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• pp.241-251
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• 2001

In this paper, optimal bum-in time to minimize the total mean cost, which is the sum of manufacturing cost with burn-in and cumulative warranty-related cost, is obtained. When the products with cumulative pro-rata warranty have high failure rate in the early period (infant mortality period), a burn-in procedure is adopted to eliminate early product failures. After burn-in, the posterior product life distribution and the warranty-related cost are dependent on burn-in time; long burn-in period may reduce the warranty-related cost, but it increases the manufacturing cost. The paper provides a methodology to obtain total mean cost under burn-in and cumulative pro-rata warranty. Property of the optimal burn-in time is analyzed, and numerical examples and sensitivity analysis are studied.

• 한국건축시공학회지
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• 제7권1호
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• pp.85-90
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• 2007

According as industry develops rapidly, problem of resources exhaustion and environmental pollution is appearing. Way to use construction waste that is development of new compound material and Industry product is required. Limestone powder that is Industry product is $CaCO_3$. and vicosity is promotion effect because there is no damage to hydration of cement and powder is very thin and water tightness increases. This research purposed to analyze concrete property changing limestone fineness. According as the limestone powdered replacement ratio increases, slump and unit capacity mass increased, and the air content decreased according as the replacement ratio increases. Compressive strength and tensile strength decreased according as the limestone powder replacement ratio increases.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.1015-1020
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• 2002

Recycling of coal combustion by-product(Ash) are becoming more improtant in the utilization business as a result of the increased use of NOx reduction technologies at coal-fired power plants. Current disposal methods of these by-products create not only a loss of profit for the power industry, but also environmental concerns that breed negative public opinion. This research made Precast block for environment-friendly secondary product and compare strength special quality of this block with existent common use brick and analyze application possibility in situ with a reserve experiment that measure strength property and manufacture method to handle coal ash produced in Bo-ryung thermoelectric power plant.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제26권4호
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• pp.315-353
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• 2019

Orders and types of entire and meromorphic functions have been actively investigated by many authors. In the present paper, we aim at investigating some basic properties in connection with sum and product of relative (p, q)-𝜑 order, relative (p, q)-𝜑 type, and relative (p, q)-𝜑 weak type of meromorphic functions with respect to entire functions where p, q are any two positive integers and 𝜑 : [0, +∞) → (0, +∞) is a non-decreasing unbounded function.

• Korean Journal of Mathematics
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• 제26권2호
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• pp.215-269
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• 2018

Orders and types of entire functions have been actively investigated by many authors. In this paper, we investigate some basic properties in connection with sum and product of relative (p, q, t) L-th order, relative (p, q, t) L-th type, and relative (p, q, t) L-th weak type of entire functions with respect to another entire function where $p,q{\in}{\mathbb{N}}$ and $t{\in}{\mathbb{N}}{\cup}\{-1,0\}$.

• 호남수학학술지
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• 제38권3호
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• pp.507-552
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• 2016

For a complex number q and a divisor function ${\sigma}_1(n)$ we define $$C(q):=q{\prod_{n=1}^{\infty}}(1-q^n)^{16}(1-q^{2n})^4,\\D(q):=q^2{\prod_{n=1}^{\infty}}(1-q^n)^8(1-q^{2n})^4(1-q^{4n})^8,\\L(q):=1-24{\sum_{n=1}^{\infty}}{\sigma}_1(n)q^n$$ moreover we obtain the number of representations of $n{\in}{\mathbb{N}}$ as sum of 24 squares, which are possible for us to deduce $L(q^4)C(q)$ and $L(q^4)D(q)$.

• 펄프종이기술
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• 제30권1호
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• pp.59-70
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• 1998

A steady-state molecular diffusion experiment was conducted to evaluate the water vapor proof properties of paper Handsheets prepared from unbleached Itraft pulps(UKP) and old newspapers(ONP) and four different types of polymer-laminated white duplex board were tested under appropriate standard conditions. The diffusivity was determined on the basis of the Fickean first law. Results obtained from this study can be summarized as follows ; 1. The diffusivity data for handsheets showed about $10^{-5}cm^2/min$. whereas polymer-laminated paperboards had remarkably improved water-vapor resistance with about $10^3 to 10^4$ times lower diffusivity : 2. Sheet basis weight, wet-swelling and sizing degree had little influence on the diffusivity of paper; 3 Linear relationship existed between sheet density and diffusivity, and, 4. Highly sfgnificant linear relationship could be observed between diffusivity and Darcy s gas permeability. Results indicate that diffusivity, an intrinsic property of paper, can provide a valuable information for precise evaluation and improved quality control of water-vapor proof properties of paper.

• Journal of Computational Design and Engineering
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• 제2권1호
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• pp.38-46
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• 2015

Augmented reality based on projection, called "Spatial Augmented Reality (SAR)", is a new technology that can produce immersive contents by overlapping virtuality and real-world environment. It has been paid attention as the next generation digital contents in media art and human-computer interaction (HCI). In this paper, we present a new methodology to evaluate the product appearance design more intuitively by means of SAR technique. The proposed method first projects the high-quality rendered image considering the optical property of materials onto the mock-up of a product. We also conduct a projector-camera calibration to compensate a color distortion according to a projector, a projection surface and environment lighting. The design evaluation methodology we propose offers more flexible and intuitive evaluation environment to a designer and user (evaluator) than previous methods that are performed via a digital display. At the end of this research, we have conducted a case study for designing and evaluating appearance design of an automobile.