• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.416-421
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• 2003

To develop an easy, low-cost method for evaluating the degree of weathering by radioactive prospecting, radioactive prospecting and the investigation of the degree of weathering were carried out in the southern Kitakami massif of Iwate Prefecture, Japan, in which weathering granitic rocks was distributed. Fifty outcrops in the study area were selected, and strength of the gamma-rays emitted from the weathering bedrock of $^{40}K,\;^{214}Bi,\;and\;^{208}Tl$ was measured for 15 minutes at each point. At the same points, soil hardness was measured on the surface of the outcrop with a Yamanaka soil penetration tester. In addition, 100cc samples of each outcrop were taken with the sampler. The samples were analyzed by XRD, and the kind of the rock-forming minerals containing K was identified. We then compared the degree of weathering and the radioactive prospecting results by using K as an indicator. The relation between $^{40}K/^{208}Tl$ gamma rays counting rate by the radioactive prospecting and the hardness index showed a positive correlation as a result of the investigation, and the correlation coefficient ($R^2$) was 0.67.Moreover, when $^{40}K/^{208}Tl$ gamma rays counting rate emitted from the bedrock was low, the number of rock-forming mineral species containing K was also low. Thus, it was found that $^{40}K/^{208}Tl$ gamma rays counting rate measured by the radioactive prospecting could be used as an indicator of the degree of weathering.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.217-223
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• 2017

Background: In Korea, 6-year-old ginseng root is economically more important than 4 or 5-year-old roots. In general, the root age is determined by counting the number of stem vestiges. However, this method does not accurately estimate ginseng root age. Methods and Results: In this study, the stem vestige counting method was used to survey a total of 18,395 fresh ginsengs cultured in 2014, and 2015, to determine the accuracy of this method. The proportion of 6-year-old roots, with more than four stem vestiges, was 46.1% in 2014. For the cultivar Chunpoong cultivated in Eumseong and Goesan countries in 2015, the proportion of more than four stem vestiges was 55.9%, and 43.5%, respectively. The proportion of more than four stem vestiges for the Gumpoong cultivated in Eumseong and Yangpyeong countries was 67.0%, and 35.1%, respectively, whereas that for the cultivar Yunpoong was 36.0% and 61.0%, respectively. Moreover, it was confirmed that differences in the levels of Rg1 will enable root age determination. Conclusions: Root age determination by the stem vestige test was found to differ depending on the environmental and cultivation conditions. To determine the age of ginseng roots, a comprehensive method, such as counting stem vestiges and evaluating differences in ginsenoside levels, should be applied.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.5
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• pp.51-70
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• 2017

The reliability of broadcasting over vehicular ad hoc networks (VANETs) is one of the most critical factors for driving safety applications. There exists limitations to improve the reliability of broadcast transmissions in saturated VANETs where previous proposals in literature tackle the problem by heuristically adapting the size of the contention window (CW). This paper considers improving the reliability by proposing a new probability model based on the counting methods of permutations and combinations, which counts all the possible cases of broadcast failures in a single-hop broadcast transmission for a given CW. From the model, we calculate the best CW size given the number of contention nodes, which significantly improves the reliability and satisfying the timely dissemination of emergency broadcasting messages. Through extensive VANET simulations with varying densities, we show that our model maintains near 100 percent success rate for single-hop broadcast as well as multi-hop broadcast (e.g. 40 hops) and achieves minimal broadcast delay.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.913-919
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• 2012

This paper presents results for dispensing and measuring micro-particles using a pneumatic dispensing system. Particle-suspended liquid droplets were dispensed and analyzed quantitatively at various particle concentrations and applied pressures. By using a developed experimental setup, the number of particles and the particle volume ratio in sequentially dispensed droplets were measured. Hydrophilic and hydrophobic surfaces were tested to find a suitable surface for counting the number of particle. It was confirmed that the dispensed particles concentrated into the center of the droplet on the smooth CD surface after evaporation of liquid. As the applied positive pressure increased, the number of particles per droplet increased consistently and the volume fraction of particles remained constant.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.5
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• pp.23-29
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• 1991

Uncertainty is studied in the measurements of average packing density, thickness of packed spheres and transmittance in the experiments to study the effect of the bed height and the existence of the bed side walls on the transmittance of radiative energy through packed spheres. The packing density of the bed is obtained by counting the number of the spheres packed in three pipes with different heights. The bed height of the packed spheres is estimated from the number of spheres contained in the bed by using the relation between the bed height and the sphere number. The transmittance is obtained by dividing the intensity of the transmitted laser beam by the incoming-beam intensity. From the analysis, the uncertainity in the measurements of transmittance is shown to be less than 10.2%(95% coverage).

• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.337-344
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• 1997

In this paper, we study the isomorphism problem of Cayley permutation graphs. We obtain a necessary and sufficient condition that two Cayley permutation graphs are isomrphic by a direction-preserving and color-preserving (positive/negative) natural isomorphism. The result says that if a graph G is the Cayley graph for a group $\Gamma$ then the number of direction-preserving and color-preserving positive natural isomorphism classes of Cayley permutation graphs of G is the number of double cosets of $\Gamma^\ell$ in $S_\Gamma$, where $S_\Gamma$ is the group of permutations on the elements of $\Gamma and \Gamma^\ell$ is the group of left translations by the elements of $\Gamma$. We obtain the number of the isomorphism classes by counting the double cosets.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.72-77
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• 1996

This study was conducted to establish an identification method age for cultivated ginseng (Panax ginseng C.A. Meyer) based on counting the stem vestige at rhizome. Weight, diameters of body and lateral roots, and ratios of those diameters were overlapped with those of other ages, so these are not enough as a criterion for identification of ginseng age. Since the stem vestige at rhizome was remained clearly from the 3rd-year age, root age can be the number of stem vestige +2. The number of stem vestige should be counted at the one side of rhizome with abundant vestige for multi stewed plant. It is necessary that the number of year-ring in root is investigated for rhizome damaged plant, but it must be considered that the new year-ring can be shown clearly after around loth of June. All dormant roots had damaged rhizome by some reasons.

• Communications of the Korean Mathematical Society
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• v.20 no.3
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• pp.467-485
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• 2005

Let p and q be odd primes with p=2q+1. We study the number of solutions of congruence equations $ax^i\;+\;by^j\;{\equiv}\;c$ (mod p) and a$ax^i\;+\;by^j\;+\;dz^t\;{\equiv}\;c(modp)$

• Bulletin of the Korean Mathematical Society
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• v.54 no.6
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• pp.1883-1891
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• 2017

An optimally labelled graph of bandwidth 2 is an ordered pair (G, f) where G is a simple graph with bw(G) = 2 and $f:V(G){\rightarrow}[n]$ is a bijection such that bw(G, f) = 2. In this paper, the number of optimally labelled graphs of bandwidth two of order n is enumerated by counting linear forests.

• Journal for History of Mathematics
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• v.15 no.1
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• pp.43-56
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• 2002

Hong, Jung-Ha(1684-\ulcorner ) explained 78 problems which look for the length of right triangle satisfying the given conditions by the Pythagorean theorem or the ratio of similarity in the chapter ‘Goo-Go-Hoh-Eun-Moon’of the 5th volume of his book Goo-Ill-Jeep. Most questions are formulated by equations of degree 2, 3, 4 which mostly have rational number solutions and part of the equations are expressed by counting stick. The explanation of each question describes the procedure to make the equation in detail, but only presents the solution with a few steps to solve.