• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.110-118
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• 2006

Cryptographic protocol design in a two-party setting has of tel ignored the possibility of simultaneous message transmission by each of the two parties (i.e., using a duplex channel). In particular, most protocols for two-party key exchange have been designed assuming that parties alternate sending their messages (i.e., assuming a bidirectional half-duplex channel). However, by taking advantage of the communication characteristics of the network it may be possible to design protocols with improved latency. This is the focus of the present work. We present three provably-secure protocols for two-party authenticated key exchange (AKE) which require only a single round. Our first, most efficient protocol provides key independence but not forward secrecy. Our second scheme additionally provides forward secrecy but requires some additional computation. Security of these two protocols is analyzed in the random oracle model. Our final protocol provides the same strong security guarantees as our second protocol, but is proven secure in the standard model. This scheme is only slightly less efficient (from a computational perspective) than the previous ones. Our work provides the first provably- secure one-round protocols for two-party AKE which achieve forward secrecy.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.35-43
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• 2006

An MPI Checkpointer is a tool which provides fault-tolerance through checkpointing The previous researches related to the MPI checkpointer have focused on automatic checkpointing and recovery capabilities, but they haven't considered portability issues. In this paper, we discuss design and implementation issues considered for portability when we developed an MPI checkpointer called STFT. In order to increase portability, firstly STFT supports the abstraction interface for a single process checkpointer. Secondly, STFT uses a user-based checkpointing method, and limits possible checkpointing places a user can make. Thirdly, STFT lets the MPI_Init create network connections to the other MPI processes in a fixed order. With these features, we expect STFT can be easily adaptable to various platforms and MPI implementations, and confirmed STFT is easily adaptable to LAM and MPICH/P4 with the prototype Implementation.

• 한국정보컨버전스학회:학술대회논문집
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• 2008.06a
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• pp.135-140
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• 2008

Recently in the Mongolian wireless marketplace, many E-commerce companies have been making considerable investments in the technological development of M-commerce, taking competitive advantage of new business possibilities offered by Internet-based wireless technologies. In the Mongolian wireless marketplace, this new mobile environment opens the door for new and exciting market opportunities in mobile services and applications. In the near future, these companies will be looking toward M-commerce services as a supplemental source of revenue in the mobile marketplace. This paper examines the roles of M-commerce in the consumers' in order to promote the consumers' loyalty in the booming M-commerce. This paper contains theory that focuses on the basic concepts of the M-commerce environment, its wireless network technologies, and its applications infrastructure. Upon searching for references to assist us in establishing a market hypothesis, we discovered that few comprehensive studies on consumer perspective and behavior related to M-commerce services actually exist in the literature. In the area of M-commerce, many companies neglect the consumer perspective, concentrating only on technological factors only when formulating their market strategies. And, due to technological blindness, many companies were not able to succeed in end-user E-commerce services. Given that fact, this paper formulates a consumer-centric research model. In order to prove the research model, we chose the survey method which allows for the collection of large amounts of data from a sizeable population in a highly economical way. Through the survey, this paper defines consumer's attitudes towards M-commerce services by identifying potential Business-to-Commerce(B2C) applications and its primary target groups in terms of gender and age, and by investigating whether consumers recognize the value proposition of M-commerce applications and services. As shown in the data analysis and results, this research concludes that M-commerce development in Mongolia is still at its infancy, and that the implementation of M-commerce depends not only on technological progress, but also on consumer attitudes and their willingness to adopt M-commerce services. As well, other complex cross-cultural factors-socially, economically, culturally, et cetera-enter strongly into the equation.

• Journal of Families and Better Life
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• v.33 no.3
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• pp.31-48
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• 2015

This study examined the factors affecting the client's binge drinking, and the client and parents' change led by family therapy. From August to November 2011, the counseling case of this research was consisted of a total of 9 sessions-individual, parents, mother-daughter, father-daughter, and family counseling. This study utilized verbatim and audio recordings, and employed Miles and Huberman(1994) matrix and network to analyze the data. The findings of the study revealed that the factors that influenced the client's binge drinking included the family's dysfunctional communication method, adverse rearing attitude owing to unresolved emotional problems from the family-of-origin, and the client family's peculiar environment and culture. The therapist's intervention included making the client aware of his own problem, helping to gain insight and understand the parents' family-of-origin, connecting the past family-of-origin and the present, identifying attempted solutions, making aware of new change, and suggesting new communication methods. Through the therapist's intervention employing MRI interactional family therapy model and Bowen's family systems theory, the family members experienced changes; perception of all family members that participated in the counseling changed, and accordingly, their communication method and attitude changed as well. Through these changes in the family, the client's alcohol consumption reduced in terms of both frequency and amount, thus was able to solve their binge drinking problem.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.5
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• pp.275-285
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• 2006

This paper proposes an efficient market mechanism-based resource transaction model for grid computing. This model predicts the next resource demand of users and suggests reasonable resource price for both of customers and resource providers. This model increases resource transactions between customers and resource providers and reduces the average of transaction response times from resource providers. For prediction accuracy improvement of resource demands and suggestion of reasonable resource price, this model introduces a statistics-based prediction model and a price decision model of microeconomics. For performance evaluating, this paper measures resource demand prediction accuracy rate of users, response time of resource transaction, the number of resource transactions, and resource utilization. With 87.45% of reliable prediction accuracy, this model works on the less 72.39% of response time than existing resource transaction models in a grid computing environment. The number of transactions and the resource utilization increase up to 162.56% and up to 230%, respectively.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.12
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• pp.642-652
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• 2001

Recently, the advent of World-Wide-Web(WWW) and the explosive popularity of the Internet gave birth to collaborative applications which were enabled by computers and networks as their primary media. The progress of 3D computer graphics enabled collaborative application with 3D virtual environments or distributed virtual environments. In this paper, we explain our implementation of the Share collaboration engine which is for collaboration applications based on a distributed virtual environment. We introduce Virtual Architectural Engineering 2000 (VAE2000) that is our pilot application implemented with the Share collaboration engine. The Share collaboration engine proposes a new Share network architecture for management of participants, and it provides some synchronization methods for 3D objects in virtual collaboration. VAE2000 is an experimental application that tries to prevent wastes of human, material and time resources in networked virtual collaboration.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.346-353
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• 2002

The explosive increase of World Wide Web usage has incurred significant amount of network traffic and server load. To overcome these problems, web proxy caching replicates frequently requested documents in the web proxy closer to the users. Cache utilization depends on the replacement policy which tries to store frequently requested documents in near future. Temporal locality and Zipf frequency distribution, which are commonly observed in web proxy workloads, are considered as the important properties to predict the popularity of documents. In this paper, we propose a novel cache replacement policy, called Adaptive LFU (ALFU), which incorporates 1) Zipf frequency distribution by utilizing LFU and 2) temporal locality adaptively by measuring the amount of the popularity reduction of documents as time passed efficiently. We evaluate the performance of ALFU by comparing it to other policies via trace-driven simulation. Experimental results show that ALFU outperforms other policies.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.2
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• pp.81-89
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• 1996

A design method of fuzzy modeling is presented for the model identification of route choice of traffic problems.The proposed fuzzy modeling implements system structure and parameter identification in the eficient form of""IF..., THEN-.."", using the theories of optimization theory, linguistic fuzzy implication rules. Three kinds ofmethod for fuzzy modeling presented in this paper include simplified inference (type I), linear inference (type 21,and proposed modified-linear inference (type 3). The fuzzy inference method are utilized to develop the routechoice model in terms of accurate estimation and precise description of human travel behavior. In order to identifypremise structure and parameter of fuzzy implication rules, improved complex method is used and the least squaremethod is utilized for the identification of optimum consequence parameters. Data for route choice of trafficproblems are used to evaluate the performance of the proposed fuzzy modeling. The results show that the proposedmethod can produce the fuzzy model with higher accuracy than previous other studies -BL(binary logic) model,B(production system) model, FL(fuzzy logic) model, NN(neura1 network) model, and FNNs (fuzzy-neuralnetworks) model -.fuzzy-neural networks) model -.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.165-170
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• 2016

Nano-scale power splitter based on curved plasmonic waveguides are designed by utilizing the multimode interference (MMI) coupler. To analyze easily the adaptive properties of plasmonic curverd multimode interference coupler(PC-MMIC), the curved form transforms equivalently into a planar form by using conformal transformation method. Also, effective dielectric method and longitudinal modal transmission-line theory are used for simulating the light propagation and optimizing the structural parameters at 3-D guiding geometry. The designed $2{\times}2$ PC-MMIC does not work well for quasi-TM mode case due to the bending structure, and it does not exist 3dB coupling property, in which the power splitting ratio is 50%:50%, for quasi-TE mode case. Further, the coupling efficiency is better when the signal is incident at channel with large curvature radius than small curvature radius.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.17-31
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• 2011

Damage caused by private information breach causes serious problems and huge social losses. In order to make a better policy that prevents society from suffering from the damage, we have to know about the actual size of damage. So it is needed to develop a quantitative model of private information breach that helps catching the more accurate size of damage. In our study, we suggest a method which calculate not only the costs of damage from firms' perspective but also those from individual and social perspectives. In this process, we refer to methods adopted by JNSA(Japan Network Security Association) and Ponemon Research Institue and modify it with considering our current situation. Also we try to make a new model by using new methods(web traffic analysis, survey, indirect comparison, etc.) and verify it with theories and methods from econometrics, cost accounting and theory of producer.