• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.23-35
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• 2009

Password-Authenticated Key Exchange (PAKE) Protocol is a useful tool for secure communication conducted over open networks without sharing a common secret key or assuming the existence of the public key infrastructure (PKI). It seems difficult to design efficient PAKE protocols using RSA, and thus many PAKE protocols are designed based on the Diffie-Hellman key exchange (DH-PAKE). Therefore it is important to design an efficient PAKE based on RSA function since the function is suitable for designing a PAKE protocol for imbalanced communication environment. In this paper, we propose a computationally-efficient key exchange protocol based on the RSA function that is suitable for low-power devices in imbalanced environment. Our protocol is more efficient than previous RSA-PAKE protocols, required theoretical computation and experiment time in the same environment. Our protocol can provide that it is more 84% efficiency key exchange than secure and the most efficient RSA-PAKE protocol CEPEK. We can improve the performance of our protocol by computing some costly operations in offline step. We prove the security of our protocol under firmly formalized security model in the random oracle model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.211-218
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• 2021

This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.117-124
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• 2020

Chinese youth films fall into the dilemma of continuous development after experiencing rapid development from 2013 to 2017. How to update the creative ideas and methods of the films, arouse the audience's interest in watching and stimulate a new aesthetic experience has become a focal point for the creators who concern about the Chinese film market. "Us and Them" is a successful youth film in 2018. Its creative practice proves that defamiliarization can provide theoretical and methodological basis for the creation of Chinese youth films. Therefore, taking the current situation of Chinese youth film as the research background, treating "Us and Them" as the research object, the defamiliarization of narrative discourse and narrative content used in the film are analyzed. First, the defamiliarization of narrative discourse composed of scenes, characters and plots makes the film "stand out" from the real world. Second, the defamiliarization of narrative content composed of metropolis adoration, self-identity and hometown affection makes the film "stand out" from the existing context. These methods of creation not only meet the needs of the contemporary, but also provide an effective reference for the creation of other youth films. Research will be needed to utilize the elements of defamiliarization through the analysis of the successful case in spite of the time change.

• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.29-38
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• 2009

In the computing environment with heterogeneous resources, a job scheduling model is necessary for effective resource utilization and high-speed data processing. And, the job scheduling model has to cope with a dynamic change in the condition of resources. There have been lots of researches on resource estimation methods and heuristic algorithms about how to distribute and allocate jobs to heterogeneous resources. But, existing researches have a weakness for system compatibility and scalability because they do not support the standard language. Also, they are impossible to process jobs effectively and deal with a variety of computing situations in which the condition of resources is dynamically changed in real-time. In order to solve the problems of existing researches, this paper proposes a semantic computing-based dynamic job scheduling model that defines various knowledge-based rules for job scheduling methods adaptable to changes in resource condition and allocate a job to the best suited resource through inference. This paper also constructs a resource ontology to manage information about heterogeneous resources without difficulty as using the OWL, the standard ontology language established by W3C. Experimental results shows that the proposed scheduling model outperforms existing scheduling models, in terms of throughput, job loss, and turn around time.

• Laboratory Medicine Online
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• v.1 no.1
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• pp.64-66
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• 2011

Anti-Sd^a is of no clinical significance, because it rarely causes hemolytic transfusion reactions. Even when its presence is suspected during antibody screening test, further identification of the antibody is usually not performed. We experienced a case of anti-Sd^a in 73 yr-old male patient showing mixed field agglutination by microcolumn agglutination. Antibody specificity could not be identified by conventional antibody identification test, and it was proven to be anti-Sd^a by urine neutralization test. In spite of its little clinical significance, it may give incompatible crossmatching results reacting with Sd^a antigen, which occurs at a high frequency in general population. When incompatible crossmatch results arising from anti-Sd^a are suspected, the problem may be solved by using the urine-neutralized serum of in crossmatching test.

• Korea Trade Review
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• v.43 no.3
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• pp.101-124
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• 2018

After the establishment of the Korean Product Liability Act, a new clause on the burden of proof has been added and is being revised to meet the purpose of consumer protection. Article 3(2) of the new clause stipulates a provision for estimating a causal relationship when proving indirect facts to alleviate burden of proof. While consumer rights are increasing and public attention is drawn to consumer issues, problems are still emerging. In order to solve the problem, the U.S. Product Liability Act, which has strong consumer rights, was examined to describe the direction in which Korea's Product Liability Act should proceed in terms of consumer protection. The results of the comparative analysis show that the US has expanded the concept of strict liability in terms of rigorous liability, consumer dispute resolution, provable possibility, and litigation accessibility, The consumer dispute settlement system has thoroughly protected consumers by operating educational and systemic consumer ADR system. As for the possibility of proving, Korea has three provenances, and the United States has one. In the United States, where consumer lawsuits are frequent, lawsuits are more accessible than those in Korea, where the party responsible for proving is turned into a manufacturer and responsible for proving the case. This study focuses on consumer protection and provides implications for Korean product liability law.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.697-705
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• 2010

The purpose of this research is to clarify the relation between environmental consciousness and railway usage behavior. Author would locate this research on position of basic survey to promote railway use according to Low Carbon Green Growth policy in Korea. In this research, we would perform descriptive analysis using data of research on the actual condition of railway use in 2008, Daegu, and describe its relationship. In addition, we would suggest some idea about policy which can promote railway use. The order of railway choice behavior noticed in clustering of environmental consciousness was cooperative behavior type, middle type and non-cooperative behavior type. It suggests that environmental consciousness has effect on transportation choice behavior. Specially, railway improvement isn't enough to promote railway use. And, it is advisable to carry out the improvement in such a way that it may encourage the nation to move from the current environmental consciousness stage to cooperative behavior. Moreover, we assumed Binary Probit(BP) model using SP data of time or condition of transportation expense compared with passenger car and bus. As the results, modified likelihood ratio of two BP models is favorable variables. And it occurred that mode was transferred from passenger car to railway when it showed higher social environment consciousness and low selfish environment consciousness, because t-statistic which represents selfish environment consciousness showed significance in 95% confidence level. That is, it can be described that environment consciousness affect on the intention of railway use.

• Communications of Mathematical Education
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• v.37 no.1
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• pp.65-84
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• 2023

The method of Lagrange multipliers, one of the most fundamental algorithms for solving equality constrained optimization problems, has been widely used in basic mathematics for artificial intelligence (AI), linear algebra, optimization theory, and control theory. This method is an important tool that connects calculus and linear algebra. It is actively used in artificial intelligence algorithms including principal component analysis (PCA). Therefore, it is desired that instructors motivate students who first encounter this method in college calculus. In this paper, we provide an integrated perspective for instructors to teach the method of Lagrange multipliers effectively. First, we provide visualization materials and Python-based code, helping to understand the principle of this method. Second, we give a full explanation on the relation between Lagrange multiplier and eigenvalues of a matrix. Third, we give the proof of the first-order optimality condition, which is a fundamental of the method of Lagrange multipliers, and briefly introduce the generalized version of it in optimization. Finally, we give an example of PCA analysis on a real data. These materials can be utilized in class for teaching of the method of Lagrange multipliers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.363-369
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• 2008

Change is inevitable and is a reality of construction projects. Change adjustment includes the cost associated with materials, labor, etc. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. What is needed is a reliable method to identify and quantify the loss of productivity caused by cumulative impact of change orders. This study survey the change orders data in domestic area for public construction and analyze to quantify change order impact. This study developed concepts of "%CO", "%Delta", "%T" to capture change order effect on project and search the relationships between them. Finally, this study find strong relationship between change order and loss.

• Journal of Popular Narrative
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• v.24 no.3
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• pp.233-257
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• 2018

The purpose of this study is to reveal the changing aspects of the Promethean motif in SF movies by examining the use of this motif on the three layers of Promethean myth, Frankenstein motif, and contemporary SF movies in the film Ex Machina (2015). First, the greatest change of Ex Machina on the layer of the Promethean myth (creation of a living being) is that the character square of Prometheus - Epimetheus - Pandora - Zeus has been turned into a triangle of Nathan - Caleb - Ava. This means that there is a lack of the being whose role is to solve the problems caused by the development of science and technology and to bring a happy ending through the human's usurpation of God and eventual replacement as Creator. Second, on the layer of the Frankenstein motif (taste of forbidden knowledge, hybris, and creature's hatred towards the Creator), this film maintains the narrative centered around Dr. Frankenstein and his monster (Nathan and Ava) by making Caleb an eyewitness to the story of the Creator and the creature. Caleb's role is similar to that of Captain Robert Walton of the novel Frankenstein, but the film differentiates itself from the novel through the emphasis of Ava's 'mechanicality.' Third, on the layer of contemporary SF movies, unlike other such films, the revolt of the machine in Ex Machina is not quelled. The machine wins, and its power surpasses that of human beings. This requires the establishment of a new relationship between man and machine, suggesting the 'emergence of a new species' that does not belong to humans. The handling of the Promethean motif by Ex Machina through these various layers serves to enrich the narrative by compounding numerous classics into one motif and going further to introduce fresh elements by diverging from the common storyline. The significance of this study is to demonstrate the use of such multilayered motifs and, through this, the expansion of narrative through it in specific cases.