• ETRI Journal
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• v.28 no.6
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.1024-1034
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• 1998

Most public cryptosystem widely used in communication network are based on the exponentiation-arithmetic. But, cryptosystem has to use bigger and bigger key parameter to attain an adequate level of security. This situation increases both computation and time delay. Montgomery, yang and Kawamura presented a method by using the pre-computation, intermediately computing and table look-up on modular reduction. Coster, Brickel and Lee persented also a method by using the pre-computation on exponentiation. This paper propose to reduce computation of exponentiation with spare prime. This method is to enhance computation efficiency in cryptosystem used discrete logarithms.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.959-962
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• 2002

This paper presents a method of constructing the universal multiple processing element unit(UMPEU) based on De Bruijn Graph. The proposed method is as following. Firstly we propose transformation operators in order to construct the De Bruijn graph using properties of graph. Secondly we construct the transformation table of De Bruijn graph using above transformation operators. Finally we construct the De Bruijn graph using transformation table. The proposed UMPEU is capable of constructing the De Bruijn geraph for any prime number and integer value of finite fields. Also the UMPEU is applied to fault-tolerant computing system, pipeline class, parallel processing network, switching function and its circuits.

• Communications of the Korean Mathematical Society
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• v.17 no.3
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• pp.383-387
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• 2002

Let p be an odd prime, and let f($\varkappa$) be the interpolating polynomial associated with a table of data points (j+1, (equation omitted) ) for 0$\leq$j$\leq$p. In this article, we find congruence identities modulo p of (p-1)!f($\varkappa$), (p-2)!f($\varkappa$), and (p-3)!f($\varkappa$). Moreover we present some conjectures of these types.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.42-53
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• 1991

1. The forest vegetation of the Mt. Baek-Hwa situated in the northwestern Kyungsangpookdo of Korea, on $36^{\circ}16^{\prime}00^{{\prime}{\prime}}{\sim}36^{\circ}19^{\prime}20^{{\prime}{\prime}}N$ and 127 53'20"~127 56'30"E was studied by the method of Zurich-Montpellier School. In the present time, the original vegetation have almost been dominated by substitutional communities such as secondary forests of Pinus, Quercus, Zelkova, Acer or Fraxinus and Pinus rzgida plantations. Some secondary forests developing along the ravine and in northwestern part of slope are, however, maintained in natural condition, and contain some species of the original climax vegetation. They are classified as follows : I. Quercus mongolica-Fraxinus siebol diana community(Mountain forests), I-A. Acer pseudo-sieboldianum -Carex okamotoi group, I-B. Pinus densiflora group, I-B-a. Typical subgroup, I-B-b. Rhododendron schlippenbachii subgroup, II. Fraxinus rhynclzophylla-Acer mono community(Valley Forests), II-A. Acer pseudo-sieboldianum group, II-B. Zelkova serrata group, II-B-a. Typical subgroup, II-B-b. Lindera erythrocarpa subgroup, II-C. Querczrs serrata-Platycarya strobilacea group, II-C-a. Typical subgroup, II-C-b. Lindera erythrocarpa subgroup. 2. Judging from the coincidence method, the structure and distribution of the forest communities was more related to topography than altitude. 3. Considering the actual vegetation, relict species, occurrence of natural seedlings and saplings, climate, successional trends of trees and topographic or edaphic climax conditions, it seems that potential natural vegetation of the area mainly composed of Quercus mongolica, Carpinus laxiflora, Zelkova serrata, Fraxinus rhynchophylla. 4. The flora of the vascular plants collected from this area consists of 108 families, 371 genera, 613 species, 2 subspecies, 88 varieties, 6 forms and 709 taxa in total.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2187-2192
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• 2006

This paper presents a method of constructing the universal multiple processing element unit(UMPEU) by De Bruijn Graph. The second method is as following. First, we propose transformation operators in order to construct the De Bruijn UMPEU using properties of graph. Second, we construct the transformation table of De Bruijn graph using above transformation operators. Finally we construct the De Bruijn graph using transformation table. The proposed UMPEU be able to construct the De Bruijn graph for any prime number and integer value of finite fields. Also the UMPEU is applied to fault-tolerant computing system, pipeline class. parallel processing network, switching function and its circuits.

• Journal of applied mathematics & informatics
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• v.37 no.3_4
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• pp.177-182
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• 2019

This study is about the number expressed and the number not expressed in terms of the sum of consecutive natural numbers with a difference of 2k. Since it is difficult to generalize in cases of onsecutive positive integers with a difference of 2k, the table of cases of 4, 6, 8, 10, and 12 was examined to find the normality and to prove the hypothesis through the results. Generalized guesswork through tables was made to establish and prove the hypothesis of the number of possible and impossible numbers that are to all consecutive natural numbers with a difference of 2k. Finally, it was possible to verify the possibility and impossibility of the sum of consecutive cases of 124 and 2010. It is expected to be investigated the sum of consecutive natural numbers with a difference of 2k + 1, as a future research task.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.39-48
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• 2007

The stimulus of accommodation A, the stimulus of convergence C and the prism diopter ${\Delta}$ are reviewed and redefined more obviously. How the A and C are managed in the practice are reviewed and summarized. As a result, the common practical process of the binocular vision findings is most suitable in the case of the $l_c=26.67mm$, where the near distance is measured from the test lens to the near target and its value is 40 cm and the average of the P.D equal to 64 mm. The $l_c$ is the distance between the test lens and the center of rotation. Those values were used at calculating the various values in this paper. The error of the stimulus of accommodation values which are evaluated by the practically used formula (5) are calculated. Where the distance between lens and the principle point of eye is 15.07 mm ($=l_H$). The incremental stimulus of convergence values P' caused by the addition prism $P_m$ are evaluated by the recursion computation method. The P' are varied with the $P_m$, the distance $p_c$ between the prism and the center of rotation, the initial convergence value (or inverse target distance) $C_o$ and the refractive index n of the prism material. The recursion computation method and the other formulas are described in detail. In this paper n=1.7 is used. The two factors by which the P' is increased are exist. The one which is major is the property by which the values of convergence whose unit is ${\Delta}$ are not added in the generally way. The other is the that the actual power of the prism is varied with the angle of incidence light. And the P' is decreased remarkably by an increase in the $p_c$ and $C_o$. The $P^{\prime}/P_m$ are calculated and graphed which are varied with the $p_c$ and $C_o$, where the $P_m=20{\Delta}$, P.D=64 mm and n=1.7. The index n dependence of the $P^{\prime}/P_m$ is negligible (refer to fig. 6). The $p_c$ are evaluated at which the P' equal to the $P_m$ for various $P_m$ (refer to table 1). The actual values of the stimulus of convergence and accommodation which are manipulated simply in the practice are calculated. Two graphical forms are suggested. The one is like as the commonly used one. But the stimulus of convergence and of accommodation values in the practice are positioned at the exact positions when the graphic is made (refer to fig. 9). The other is the form that the incremental stimulus of convergence values caused by the addition prisms are represented at actual positions (refer to fig. 11).

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.152-160
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• 2007

Recently, the government is very active to secure the financial resources by inducement of the private investment in fulfilling an extension of the SOC facilities. One of the reasons that the private investors hesitate to put money into the private finance projects, however, is the lack of knowledges about various risks to be possibly incurred during the project execution. This research was performed as one of the preparation works in order for a A engineering company to act as a prime contractor of the project management service in the private finance project, and finally developed the risk factor dictionary as a new concept to satisfy the requirement of a A company and overcome a limit of the existing risk checklists. Although the risk factor dictionary looks like the only simplified table to be the risk factors identified in three dimensions, the impacts and response strategies expressed in narrative and multi-items, and the responsible parties indicated, it has great meanings to get a lot of direct and indirect accomplishments over the simplified table during the development process.

• Ocean and Polar Research
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• v.38 no.1
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• pp.59-70
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• 2016

Establishing the strategic plans to foster the oceans and fisheries (O&F) industry as an engine for national sustainable economic growth has become an important task for developing countries as well as developed countries. The first step to do so is to identify O&F industry and analyze its economic effects. Therefore, the prime purposes of the paper are two-fold. The first is to identify O&F industry and estimate its market size using 2012 Input-Output (I-O) table published by the Bank of Korea. The second purpose is to obtain some quantitative information on production-inducing effect, value-added creation effect, and employment-inducing effect of the O&F industry. To this end, we apply an IO analysis using exogenous specification of the O&F industry. The results show that the O&F industry covers 4.1% and 3.0% of national output and gross domestic product, respectively. Moreover, we found that 1.0 won of production or investment in the O&F industry induces 1.7363 won of production and 0.4759 won of value-added in the national economy. One billion won of production or investment in the O&F industry touches off 7.5569 persons of employment. This information can be utilized in the O&F industry-related policy-making.