• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.125-143
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• 2015

As improving the life quality of citizen because of development of Urbanization and Information, civil application service of public institutions has been changed. The government provides a 24-hour civil service of e-government, public institutions operate U-complaints call center to pursue a personalized service to customers. As customer service are diversified, the inconvenience of service is increased. Therefore, public institutions instituted U-complaints call center to solve increased complaints. In early days, public institutions operated simple call center. However, it became intelligent U-complaints call center by SNS. The more increase the importance of agents' contact customer service, the more increase Job Performance considered by Organizational Commitment & Job Satisfaction of call center agents. This study analyzed that applied to Fairness Theory with Organizational Commitment, Job Satisfaction and analyze U-complaints call center agents' role and job performance of public institutions. Proposed a research model applied to job satisfaction with key variables, organizational commitments, job satisfaction. It's expected to impact on job performance of U-complaints call center agents in public institutions. For empirical study of research model, conducted a survey of the U-complaints call center agents of public institutions. 170 samples were collected from the survey and analyze relationship between the factors. Procedural justice, distribution fairness, fairness interaction are significant influence on organizational commitment of parameters by analysis U-complaints call center agents. Procedural justice and fairness of interaction was found not to effect on parameters of job satisfaction. Also, parameter, organizational commitment have significant influence on job satisfaction. However, have no influence on job performance. Therefore, the parameters of job satisfaction have significant influence on job performance. Public institutions should adopt to improve the quality of citizen services through U-complaints call center agents.

• The KIPS Transactions:PartC
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• v.14C no.4
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• pp.331-340
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• 2007

Mobile network environments are the environments where mobile devices are distributed invisible in our daily lives so that we can conventionally use mobile services at my time and place. The fact that we can work with mobile devices regardless of time and place, however, means that we are also in security threat of leaking or forging the information. In particular, without solving privacy concern, the mobile network environments which serve convenience to use, harmonized without daily lives, on the contrary, will cause a serious malfunction of establishing mobile network surveillance infrastructure. On the other hand, as the mobile devices with various sizes and figures, public key cryptography techniques requiring heavy computation are difficult to be applied to the computational constrained mobile devices. In this paper, we propose efficient PKI-based user authentication and java-based cryptography module for the privacy-preserving in mobile network environments. Proposed system is support a authentication and digital signature to minimize encrypting and decrypting operation by compounding session key and public key based on Korean standard cryptography algorithm(SEED, KCDSA, HAS160) and certificate in mobile network environment. Also, it has been found that session key distribution and user authentication is safety done on PDA.

• The KIPS Transactions:PartC
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• v.14C no.7
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• pp.553-558
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• 2007

In this paper, we introduce a set of structures and algorithms for communication efficient public key revocation in wireless sensor networks. Unlike the traditional networks, wireless sensor network is subjected to resources constraints. Thus, traditional public key revocation mechanisms such like the ordinary certificate revocation list is unsuitable to be used. This unsuitability is due to the huge size of required representation space for the different keys' identifiers and the revocation communication as the set of revoked keys grow. In this work, we introduce two communication-efficient schemes for the certificate revocation. In the first scheme, we utilize the complete subtree mechanism for the identifiers representation which is widely used in the broadcast encryption/user revocation. In the second scheme, we introduce a novel bit vector representation BVS which uses vector of relative identifiers occurrence representation. We introduce different revocation policies and present corresponding modifications of our scheme. Finally, we show how the encoding could reduce the communication overhead as well. Simulation results and comparisons are provided to show the value of our work.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.463-466
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• 2016

Sharing of product and process information with partners is a basic activity and key requirement which ensures success of distribution. ePedigree that encapsulates all of the event data from manufacturer to retail shop provides a flexible mechanism of storing and sharing traceable information to the partners of supply chain and credibility of shared information through digital signature based on Public Key Infrastructure (PKI). To generate the signature that can be authenticated through PKI, the partners of supply chain should pay for PKI certificates from Certificate Authority (CA). In case of agrifood cooperatives which consist of petty merchants or farmers, it is hard to pay for the PKI certificate for all members and is a big obstacle for the ePedigree to be applied to the supply chain. This paper proposes a private certification method of ePedigree for cooperatives. Cooperatives can apply the ePedigree using the proposed method to all the members at small cost and the proposed method can assure the credibility of information at the same level of the previous ePedigree.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.421-433
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• 2015

Recently, there have been fast-growing social network services based on the Internet environment and web technology development, the prevalence of smartphones, etc. Social networks also allow the users to convey the information and news so that they have a great influence on the public opinion formed by social interaction among users as well as the spread of information. On the other hand, these social networks also serve as perfect environments for rampant malware. Malware is rapidly being spread because relationships are formed on trust among the users. In this paper, an effective patch strategy is proposed to deal with malicious worms based on social networks. A graph is formed to analyze the structure of a social network, and subgroups are formed in the graph for the distributed patch strategy. The weighted directions and activities between the nodes are taken into account to select reliable key nodes from the generated subgroups, and the Incremental PageRanking algorithm reflecting dynamic social network features (addition/deletion of users and links) is used for deriving the high influential key nodes. With the patch based on the derived key nodes, the proposed method can prevent worms from spreading over social networks.

• Wind and Structures
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• v.20 no.1
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• pp.59-74
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• 2015

A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.7
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• pp.575-597
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• 1991

As an elegant solution of the key management scheme for a conventional cryptosystem. Diffie and Hellman introduced a public key distrbution system, whose security depends on the intractabliity of discrete loganthm problem over a finite field, and since then a lot of vartants of DH KDSS have been proposed. In this paper, we present the systematic approach to analyzing the security of a generalized DH KDS and designing an efficient and secure scheme. We classify vanous attacking methods and point out a possible way to avoid these attacks through the examples of successful attacking methods and point out a possible way to avoid these attacks through the examples of successful attack against those systems proposed so far or designed for this purpose. As security analysis tools, we present the redueiblity test, the information theoretic approach, and the protocol analysis technique, which we apply to variations of DH scheme to examine their security under all possble attacks.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.885-896
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• 2021

The general role of commercial banks is to provide financial services to the general public and business, ensuring economic and social stability and sustainable growth of the economy. Commercial banks play an important role in mobilizing and channelizing funds for investment activities. This study analyzes the impact of the key financial variables on the net profit of the selected commercial banks in Oman. The study employs times series panel data - cross-sectional analysis of the key financials of five leading commercial banks for a period of 13 years from 2007 to 2019. The results reveal that the correlation matrix of the selected variables has a positive relationship with net profit, assets, deposits, loans, and interest income. However, the findings also shows a negative relationship between net profit and net loans to total deposits ratio. The study found net loans is the main independent variable that influences the profitability of the banks since the key source of revenue comes from the lending operations. The assets, total capital adequacy ratio have a mixed effect on the profitability of commercial banks. The total deposits and capital adequacy ratio have a negative effect on profitability mainly because excessive liquidity will increase the cost of capital and reduce the return on investment. Focusing on lending operations with a sound credit portfolio will improve profitability.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.3
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• pp.81-89
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• 2019

Many authors have examined the impact of public spending on economic growth. This study uses ordinary least-squares technique to test the effect of state budget expenditure with two major components: development investment expenditure and recurrent expenditure on Vietnamese economy for the period 2000-2017. The empirical results show that the state budget expenditure of Vietnam has positive effect on the economy, however each main component has different impacts. Recurrent expenditure has significant positive impact on Vietnamese economy while there has no evidence to affirm the relationship between the development investment expenditure and the economic growth. Vietnamese government should restructure the state budget to enhance the positive effect on the economy. In the short run, Vietnam should not increase development investment expenditure due to low efficency in public investment. In the long run, it is necessary to economize recurrent expenditure to reserve a reasonable proportion of state budget for development investment expenditure to build infrastructure for developing the economy. The state budget expenditure should be restructured towards prioritizing recurrent expenditure on human and social relief, reducing public administration expenditure, allocating investment capital from the state budget for key and pervasive projects, avoiding spreading out investments as well as crowding out private investments.

• Journal of the Korean housing association
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• v.24 no.5
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• pp.77-88
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• 2013

This study is to find out how community facilities of 10-year public rental apartments are currently managed and to propose a new community program management plan by analyzing key characteristics and program needs of tenants. Site visits and questionnaire surveys have been conducted at five different complexes producing 469 results that can be summarized as follows; 1) There were significant differences in the use of facilities and vitality of community among five complexes depending on tenants' participation and efforts of management staff. It was advisable to dispatch specialists, such as housing welfare workers, who were dedicated to managing facilities and supporting community programs; 2) There were high demanded for communication facilitation programs and environmental activities. Development of communication contents and distribution of manuals to inform and educate tenants about various environmental programs will be helpful; 3) The number of community facilities in each complex should be reduced those with high demand and the regional community center should be more vitalized with supporting programs and staff.