• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.3-11
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• 2011

Evaluation of cube roots in characteristic three finite fields is required for Tate (or modified Tate) pairing computation. The Hamming weights (the number of nonzero coefficients) in the polynomial representations of $x^{1/3}$ and $x^{2/3}$ determine the efficiency of cube roots computation, where $F_{3^m}$is represented as $F_3[x]/(f)$ and $f(x)=x^m+ax^k+b{\in}F_3[x]$ (a, $b{\in}F_3$) is an irreducible trinomial. O. Ahmadi et al. determined the Hamming weights of $x^{1/3}$ and $x^{2/3}$ for all irreducible trinomials. In this paper, we present formulas for cube roots in $F_{3^m}$ using the shifted polynomial basis(SPB). Moreover, we provide the suitable shifted polynomial basis bring no further modular reduction process.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.4
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• pp.139-157
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• 2022

Finding and selecting proper reviewers is a burden on the publisher of the journal. In order to solve this problem, the online submission system started to recommend appropriate reviewers automatically. It includes a variety of new features, from recommending authors in the references of submitted papers as reviewers to finding similar papers by searching the citation index and suggesting reviewer candidates extensively. This study investigated how the online submission system provides functions such as recommendation of reviewers. As a result of examining major online submission systems, ScholarOne and Editorial Manager were recommending reviewer candidates by commercial citation index and review history platform. On the other hand, JAMS, a domestic online submission system, did not have any advanced functions such as recommendation of candidates for reviewers. Sooner or later, in Korea, it seems that more efforts should be made to improve the function of online submission system, such as recommending suitable reviewers for papers.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.219-232
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• 2023

Mobility services need to change according to the regional characteristics of the target service area. Accordingly, analysis of mobility patterns and characteristics based on Origin-Destination (OD) data that reflect travel behaviors in the target service area is required. However, since conventional methods construct the OD data obtained from the administrative district-based zone system, it is hard to ensure spatial homogeneity. Hence, there are limitations in analyzing the inherent travel patterns of each mobility service, particularly for new mobility service like Demand Responsive Transit (DRT). Unlike the conventional approach, this study applies a data-driven clustering technique to conduct spatial analyses on OD travel patterns of regional mobility services based on reconstructed OD data derived from re-aggregation for original OD distributions. Based on the reconstructed OD data that contains information on the inherent feature vectors of the original OD data, the proposed method enables analysis of the spatial characteristics of regional mobility services, including public transit bus, taxi and DRT.

• Journal of Marine Life Science
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• v.3 no.1
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• pp.38-43
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• 2018

The polychaetes are the dominant species in the benthic communities, and play an important role in improving the sediment quality through the action of ingesting organic materials. We evaluated the improvement ability of rockworm Marphysa sanguinea for the removal of organic matter. We used the three types of sediment (S1: coarse sand, S2: fine sand, S3: muddy sand), and analyzed TOC of seawater and sediment. Rockworm was effective in eliminating organic matter in the three types of sediment and the larger the particle, the higher the removal rate. Removal ability of rockworm for organic matter in sediment were calculated with 3.9856 ppm g^-1d^-1 in coarse sand, 2.8021 ppm g^-1d^-1 in fine sand, and 28.1142 ppm g^-1d^-1 in muddy sand. The results show that rockworm contributes to the removal of organic matter in the various sediment types.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.364-369
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• 2023

Time-delay estimation between two receivers is a technique that has been applied in a variety of fields, from underwater acoustics to room acoustics and robotics. There are two types of time delay estimation techniques: one that estimates the amount of time delay from the correlation between receivers, and the other that parametrically models the time delay between receivers and estimates the parameters by system recognition. The latter has the characteristic that only a small fraction of the system's parameters are directly related to the delay. This characteristic can be exploited to improve the accuracy of the estimation by methods such as Lasso regularization. However, in the case of Lasso regularization, the necessary information is lost. In this paper, we propose a method using Elastic Net that adds Ridge regularization to Lasso regularization to compensate for this. Comparing the proposed method with the conventional Generalized Cross Correlation (GCC) method and the method using Lasso regularization, we show that the estimation variance is very small even for white Gaussian signal sources and colored signal sources.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.413-423
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• 2020

Over the wide area, King Sejong Station and the nearby land are uncovered with snow and ice conditions. Therefore, the active layer on the permafrost has been formed to be much thicker than the other Antarctica region. Electrical resistivity survey of Wenner and dipole-dipole arrays was undertaken at a series of time in the freezing season at the King Sejong Station to delineate subsurface structure and to monitor active layer in permafrost terrain. Time-lapse resistivity structures are well in terms of the vegetation distribution, ground surface temperature, and snow depth. Horizontal high resistivity belt(>1826 Ωm) at very shallow depth is thickening with the lapse of time, probably caused by the freezing of the water in the pore spaces with decrease of ground temperature. Subsurface structures for the area of low snow-cover and vegetated zone area are comprised of 0~0.5 m deep high-resistive gravel-rich soil, 0.5~3 m deep low-resistive active layer, and the underlying permafrost. In contrast, the unvegetated area and high snow-buildup is characterized with high resistivities larger than approximately 2000 Ωm due to freezing of the soil throughout the year. Data interpretation and correlation schemes explored in this paper can be applied to confirm the active layer, which is expected to get thinner in additional survey during the thawing season.

• Korean Journal of Logic
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• v.3
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• pp.5-26
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• 2000

확률적 인과론은 확률관계를 통해 인과 관계를 밝히려는 이론이다. 그런데 만약 단지 C가 E의 발생 확률을 높인다는 사실을 밝히는 것으로 그치지 않고 더하여 C가 E를 발생시키는데 얼마나 기여하는지 그 기여도도 밝힐 수 있다면 우리는 원인과 결과의 관계에 대하여 훨씬 더 많은 정보를 얻을 수 있게 될 것이다. 이 글에서 나는 빼기의 개념에 기반한 멜러나 엘스의 정량적 확률적 인과론들을 살펴본 후 그 이론들이 인과적 효과도나 인과적 연관도를 밝히는데 부적절한 이론들임을 보인다. 그 후 나는 인과적 효과도클 측정하는데 보다 적절한 공식을 제시하며 이 공식에 기반하여 인과적 연관도 또는 인과적 기여도의 공식도 제시한다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.1
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• pp.37-42
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• 2004

ECF and TCF bleaching methods are favored in bleaching plants over the world due to the increasing environment constraints. However, interaction of main stages(D and O stage) in ECF bleaching have not been understood completely yet. The degradation of holocellulose as a carbohydrate model compound was investigated by SEC(size exclusive chromatography) to estimate the change of its molecular weight distribution after O and D stage combination treatment. The molecular weight distribution of holocellulose was observed in two divisions(higher and lower molecular portions). It was also shown that DO sequence was more effective than OD, and DOD or ODO was more effective than DO. D stage had a little effect on the degradation of holocellulose, while the degradation of holocellulose increased as the time of the first O stage increased.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.74-78
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• 2003

The structural property of phenolic and non-phenolic lignin has an effect on the reaction rate of lignin by oxygen and chlorine dioxide respectively. Moreover, the undesirable degradation of cellulose followed by lignin degradation is influenced by chemical charge and reaction time. In this paper, several lignin model compounds were used to illuminate the interaction of oxygen and chlorine dioxide by varying the position of O and D(OD, DO, ODO and DOD), and gas chromatography method was used to investigate the degradation of lignin by determining the content of methoxyl groups in lignin. It was shown that structural properties of lignin models were more influential on the degradation and demethylation of lignin than the above combination. Combination of oxygen and chlorine dioxide, however, was more effective in degradation of lignin than only one stage, and three stages than two stages.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.09a
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• pp.23-38
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• 1995

고분자막에 의한 기체분리는 심냉분리법, 흡수법, 흡착법등에 비하여 에너지가 절약되며 장치가 간결하고 운전비용이 낮은 이점 때문에 여러가지 기체혼합물에 대하여 여러가지 목적으로 응용되기에 이르렀다. O$_{2}$/N$_{2}$ 분리막으로 요구되는 기본특성은 1) 높은 O$_{2}$ 투과성 2) 높은 O$_{2}$ 선택성 3) 막 형성에 충분한 기계적 강도 4) 열, 화학적으로 안정성이 있어야 한다. 그런데 투과계수 P$_{O_(2)}$와 투과선택도 P$_{O_(2)}$/P$_{N_(2)}$ 관계 Fig.2 에서 보는 바와 샅이 대체로 투과선택성은 상반관계에 있어서 polyimide는 높은 선택성을 나타내고 기계적 강도가 좋고 높은 열에 대하여 안정하기 때문에 일단 막재료로 양호한 조건을 갖추고 있으나 투과계수가 크지 않아 선택도를 크게 감소시키지 않으면서 투과계수를 향성시키려는 노력이 경주되고 있다. 따라서 polyimide의 화학구조와 투과계수, 투과선택도의 관계를 고찰하는 것은 대단히 중요하다. 특히 최근에는 polyimide의 화학구조를 계통적으로 변화 시켜가면서 구조와 투과특성을 고찰한 연구가 많으며, 이러한 연구를 총망라하여 화학구조와 투과특성을 고찰한 훌륭한 총설들이 발표되어왔다. Fig.3에는 지금까지 연구된 중요한 polyimide를 형성하는 dianhydride와 diamine의 구조식을 표시하였으며 이들 구조의 변화에 의하여 기체투과계수와 투과선택도가 어떤 영향을 받는지 고찰하고자 한다.