• Journal of applied mathematics & informatics
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• 제24권1_2호
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• pp.461-470
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• 2007

In CRYPTO 1995, Bellare, $Gu\'{e}rin$, and Rogaway proposed a very efficient message authentication scheme. This scheme is secure against adaptive chosen message attacks, under the assumption that its underlying primitive is a pseudorandom function. This article studies how to weaken that assumption. For an adaptive chosen message attack, we take into account two scenarios. On the one hand, the adversary intercepts the authenticated messages corresponding to messages chosen adaptively by herself, so the verifier does not receive them. On the other hand, the adversary can only eavesdrop the authenticated messages corresponding to messages chosen adaptively by herself, so the verifier receives them. We modify the original scheme. In the first scenario, our scheme is secure if the underlying primitive is a pseudorandom function. In the second scenario, our scheme is still secure under a weaker assumption that the underlying primitive is an indistinguishable-uniform function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3572-3593
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• 2015

This article investigates the topology control problem in the space information network (SIN) using a hierarchical autonomous system (AS) approach. We propose an AS network topology control (AS-TC) algorithm to minimize the time delay in the SIN. Compared with most existing approaches for SIN where either the purely centralized or the purely distributed control method is adopted, the proposed algorithm is a hybrid control method. In order to reduce the cost of control, the control message exchange is constrained among neighboring sub-AS networks. We prove that the proposed algorithm achieve logical k-connectivity on the condition that the original physical topology is k-connectivity. Simulation results validate the theoretic analysis and effectiveness of the AS-TC algorithm.

• 대한물리치료과학회지
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• 제10권1호
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• pp.83-89
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• 2003

An electromyogram (EMG) using surface electrodes is one of the indirect tests most frequently used to ascertain muscle fatigue. An EMG can be used in two ways. The first technique determines the root mean square (RMS), which reflects the amplitude of the EMG signal. The second technique determines the median and mean power frequencies through EMG power spectrum analysis. The purpose of this article is for determine the correlation between work and percent root mean square(%RMS) and between work and MDF of EMG based on muscle contractions. It is used the %RMS, which reflects the amplitude of the EMG signal For MDF, it is used the frequency power spectrum analysis method, which involves the fast Fourier transformation (FFT) of the original Signals.

• 대한수학교육학회지:수학교육학연구
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• 제9권1호
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• pp.205-215
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• 1999

Main stream of '90s mathematics education in the U.S must be the NCTM Standards. Since it was published in 1989, much focus has put on it and numerous research has been tried to apply it to real mathematics classes. But there hasn't always good fame. Some schools have already taken the curriculum based on it and recently the negative results have been exposed. Not a few parents, teachers and experts became to be worry about that. In this situation, 1 suppose it is worth to review the original purpose of Standards, look into the recent problems related to it's application and think of improvement or alternatives. This article mainly includes first two issues and particularily considers what problems are to have to be reconsidered in Korea. The following four are what I draw as problems: Basic operations; constructivism; texts and work books; trial and error strategy and group activity.

• 한국전문물리치료학회지
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• 제5권1호
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• pp.79-90
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• 1998

Neurodevelopmental treatment(NDT) is a widely used technique by physical and occupational therapists in the treatment of neuromuscular disorders. Childeren with cerebral palsy are frequently referred for physical and occupational therapy, yet the effectiveness of treatment has not been well-documented. More than 40 years ago, the Bobath introduced a treatment concept for individuals with central nervous system impairment. A theoretical framework for the approach was based on the common belief in the 1940s that the nervous system functions in a hierarchy. Clinical aspects of the NDT approach have grown and changed during the past 40 years. This article details the original NDT concepts and looks at the concept with regard to newer theoretical frameworks of nervous system.

• 대한치과의사협회지
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• 제51권11호
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• pp.604-609
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• 2013

Crown fractures are relatively common trauma to anterior teeth, and should be restored immediately in most cases. For those who suffer from unfortunate traumatic episode, the best treatment option should be minimally invasive approach. In the presence of fractured tooth fragment, reattachment procedure creates positive emotional response in the patient and simplifies the procedure and maintenance of the patient's original tooth anatomy and occlusion. Without fractured tooth fragment, next conservative option could be direct composite restoration which is based on minimal invasion concept. This article proposes simple and very conservative techniques that anyone can do in daily practice.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2325-2331
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• 2008

This article is about a new law of railroad industry has come into effect in 2004 and that left the railroad company operated under the private system. Accordingly, it has to encounter a variety of managers on the railroad safety part too. Incheon Airport Railroad that was, from Incheon International Airport to Kimpo Airport, opened to traffic on the 23th March, 2007 as the first private railroad company in Korea. This railroad company is working hard to be a safe and convenient airport railroad. There is not operated an effective emergency response that the railroad company and the emergency response personnel without standard operation procedure, recently. The original emergency manual and the emergency procedure of the synthesized railroad safety development business. I am proposing to establish the emergency response scenario according to the different situations that the train operator.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1346-1352
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• 2007

This article presents an original work on kinetically studying the selective adsorption and recognition by molecularly imprinted polymer (MIP). With S-naproxen as template, the imprinted polymer was prepared. The result indicates that the prepared polymer shows a more complicated sorption toward S-naproxen than toward its enantiomer R-naproxen. The rate constant in the case of template appears to be a variable. There are also significant deviations from the idealized Langmuir model. Related information indicates that these, in logic, can be a result of biomimic structural and functional complements between imprint and the template, which makes the polymer capable of selectively recognizing the imprint species.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제10권2호
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• pp.135-150
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• 2006

Although improper integrals constitute a concept of great utility for Mathematics students, it appears that students are unable to assimilate this concept within the wider system of concepts they learn in their first year of Mathematics studies. In this paper we describe a competence model used in a study about the kind of understanding students possess about improper integral calculus when two registers of representation come into play. Competence will be considered as the coherent articulation of different semiotic registers. After analysing the results of a questionnaire, six students were selected to be interviewed on the basis of their overall results and the significance of their answers. For the interview, five original questions from the questionnaire were used together with a new question. In this article we will analyse, from our theoretical point of view, the work carried out by one student who was interviewed to show how our competence model works and we will discuss this formal competence model used.

• 기술사
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• 제42권6호
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• pp.42-46
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• 2009

Every year influenza contributes to the death of 72 people in the South korea, 20,000 in the U.S. and perhaps millions worldwide. The swine fever so-called the noble flu A H1N1, a strain of the flu virus, which jumped species and burst into the human population in March and April of this year. The outbreak of 2009 novel H1N1 was the fourth in 100 years. Fortunately, it led to today's comparatively tame swine flu than the vicious 1918, which was original H1N1 pandemic flu virus, killed at least 40 million worldwide in an ongoing pandemic era. Although the 2009 H1N1 which is still in full swing, this global flu epidemic is already teaching scientists valuable lessons about pandemics. Evidence accumulated these days indicates that the 2009 H1N1 was not entirely new to all human immune systems. This article introduces only an outline for our better understanding the basic mechanisms of influenza and the vaccination about longstanding fears of that worst-case scenario engendered pandemic that are paying off today.