• The Journal of Society for e-Business Studies
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• v.4 no.1
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• pp.103-115
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• 1999

The electronic cash, an electronic equivalent of the real paper money, has been recently proposed as one of the various payment methods for electronic commerce. In this paper, we design an electronic cash payment system based on a new electronic cash payment protocol that can effectively provide full anonymity and avoid double-spending. The protocol is suitable for use as the electronic cash control or electronic cash database. The protocol support also security and electronic cash property.

• Communications of the Korean Mathematical Society
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• v.39 no.1
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• pp.59-69
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• 2024

Let R be a commutative ring. An R-module E is said to be regular injective provided that Ext¹_R(R/I, E) = 0 for any regular ideal I of R. We first show that the class of regular injective modules have the hereditary property, and then introduce and study the regular injective dimension of modules and regular global dimension of rings. Finally, we give some homological characterizations of total rings of quotients and Dedekind rings.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.117-132
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• 2022

Reverse edge magic(REM) labeling of the graph G = (V, E) is a bijection of vertices and edges to a set of numbers from the set, defined by λ : V ∪ E → {1, 2, 3, …, |V| + |E|} with the property that for every xy ∈ E, constant k is the weight of equals to a xy, that is λ(xy) - [λ(x) + λ(x)] = k for some integer k. We given the construction of REM labeling for the Cartesian Product, Unions of Braids and Unions of Triangular Belts. The Kotzig array used in this paper is the 3 × (2r + 1) kotzig array. we test the konow results about REM labelling that are related to the new results we found.

• Journal of Korea Game Society
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• v.20 no.2
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• pp.61-74
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• 2020

Northeast Asia accounts for half of the world game market, worth $ 152.1 billion, and has abundant growth potential. Early e-sports in Korea could be formed through the distribution of affects of active participation of gamers and fans. Since then, the establishment of a corporate team has continued, securing stability as an industry. However, mediation rights, intellectual property disputes, and game manipulations continue, leading to a massive escaped of early fandom and the collapse of StarCraft-based ecosystems.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.17-34
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• 2006

As insurers have undergone changing customer expectations, increased cross-industry competition and restructured distribution channels, they need to enhance customer relationships, cut costs, increase agility and streamline operations while differentiating the core competency. As such, the importance of e-business transformation has increased where organizational core processes are restructured around customers and interned-based technology is adopted for flexible and adaptive information systems. This paper presents a case study of process innovation for e-business transformation in a Korea-based leading property & casualty insurance company. The company initiated three years-long e-business transformation program to remain competitive and to keep sustainable growth under risky and down economy. The program, which covered enterprise-wide business processes such as product, marketing & sales, customer, claim, investment & loan, accountings, etc., included redesigning processes from customers' viewpoint and then implementing process-aligned information systems. Leadership, sponsorship, change management, performance measurement, business and IT alignment, empowerment, and customized methodology, were emphasized throughout the program. As a result, the company could expect not only improvements in customer-centricity, sales productivity, and operational excellence but also increased revenues and profits in the next three years. The presented case addresses a feasible approach for enterprise-wide e-business transformation. Although the strategies, actions, and business and IT models are not described in detail due to confidentiality, the methodology and the success factors would be applicable to other insurers and possibly organizations in different industries.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.111-116
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• 2007

An eSeal(Electrical Seal) is an active RFID device which installed on the door of a container. The main role of the tag is to make sure the seal is not breaking by unauthorized people. Because an eSeal uses RFID system, we need to prevent eavesdrop and impersonate. Moreover, an eSeal which uses a secure protocol must not be able to duplicate. If duplication resistant property is not provide to a eSeal, an attacker may replace a object in the sealed container and reseal the container with duplicated eseal to hide breaking of the eSeal. In this paper, we provide a protocol which resist duplicate an eSeal during prevent eavesdrop and impersonation.

• The Korean Journal of Applied Statistics
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• v.28 no.1
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• pp.33-47
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• 2015

We consider an $M/E_n/1$ queueing model where customers arrive at a facility with a single server according to a Poisson process with customer service times assumed to be independent and identically distributed with Erlang distribution. We concentrate on the overshoot of the workload process in the queue. The overshoot means the excess over a threshold at the moment where the workload process exceeds the threshold. The approximation of the distribution of the overshoot was proposed by Bae et al. (2011); however, but the accuracy of the approximation was unsatisfactory. We derive an advanced approximation using the property of the Erlang distribution. Finally the newly proposed approximation is compared with the results of the previous study.

• Journal of the Korean Ceramic Society
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• v.55 no.2
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• pp.135-139
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• 2018

The glass structure and antibacterial properties of $(65-x)ZnO-xB_2O_3-35P_2O_5$ glasses were investigated. Zinc borophosphate glasses were prepared using a conventional melt-quenching technique at $1000^{\circ}C$. Glass transition temperature and CTE were studied and the structure of zinc borophosphate glasses was evaluated by FTIR. The $Zn^{2+}$ state increase with increasing ZnO content was investigated by XPS and a single sharp Zn $2P_{3/2}$ peak was confirmed, showing that Zn $2P_{3/2}$ exists as $Zn^{2+}$. In order to to evaluate the antimicrobial activity, Escherichia coli (E. coli) was used following the Japanese Industrial Standard JIS Z 2801; the E. coli death rate was found to increase with increasing $Zn^{2+}$ content of glasses.

• Journal of Korea Foundry Society
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• v.39 no.4
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• pp.61-74
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• 2019

The effects of Sr and (Ti-B) additives on the impact and fatigue properties of recycled (35% scrap content) AC4A aluminum alloy are investigated here. The acicular morphology of the eutectic Si phase of as-cast specimens was converted to the fibrous one with Sr additives. The grain size of the α-solid solution decreased by the addition of (Ti-B) additives. The crack initiation energy (E_i) of the impact absorption energy decreased due to the incorporation of an oxide film and inclusions depending on the scrap used. The modification of the eutectic Si morphology by Sr additives is considered as the main factor of the increase of the average impact absorption energy (E_t). The addition of (Ti-B) additives contributed to an increase in the occurrence of crack deflections due to the refining of α-Al grains, resulting in improved fatigue properties.

• Communications of Mathematical Education
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• v.37 no.3
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• pp.419-442
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• 2023

This study investigated fifth graders' understanding of variables from a generalized arithmetic and a functional perspectives of early algebra. Specifically, regarding a generalized perspective, we included the property of 1, the commutative property of addition, the associative property of multiplication, and a problem context with indeterminate quantities. Regarding the functional perspective, we covered additive, multiplicative, squaring, and linear relationships. A total of 246 students from 11 schools participated in this study. The results showed that most students could find specific values for variables and understood that equations involving variables could be rewritten using different symbols. However, they struggled to generalize problem situations involving indeterminate quantities to equations with variables. They also tended to think that variables used in representing the property of 1 and the commutative property of addition could only be natural numbers, and about 25% of the students thought that variables were fixed to a single number. Based on these findings, this paper suggests implications for elementary school students' understanding and teaching of variables.