• 대한수학회지
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• 제48권3호
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• pp.565-583
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• 2011

In this paper we provide characterizations for the Gromov hyperbolicity of some particular Denjoy domains and besides some sufficient conditions to guarantee or discard the hyperbolicity of some others. The conditions obtained involve just the lengths of some special simple closed geodesics in the domain. These results, on the one hand, show the extraordinary complexity of determining the hyperbolicity of a domain and, on the other hand, allow us to construct easily a large variety of both hyperbolic and non-hyperbolic domains.

• 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.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권3호
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• pp.237-241
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• 2002

In this paper, we describe how to represent hand witten decimal digits by a sequence of one to five fuzzy sets. Each fuzzy set represents an arc segment of the digit and is a Cartesian product of four fuzzy sets; the first is fur the arc length of the segment, the second is for the arc direction, the third is fur the arc shape, and the fourth is a crisp number indicating whether it has a junction point and if it has an end point of a stroke. We show that an arbitrary pair of these sequences representing two different digits is mutually disjoint. We also show that various forms of a digit written in different styles can be represented by the same sequence of fuzzy sets and hence the deviations due to different writers can be modeled by using these fuzzy sets.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.189-198
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• 2000

/$t{\partial}n$/, /$d{\partial}n$/, /$t{\partial}l$/ and /d{\partial}l$/, on the one hand, are the typical phonemes of syllabic consonants. On the other hand, /${\int}{\partial}n$/ most plausibly gives rise to the syllabic consonants. /$t{\partial}r$/ and /$d{\partial}r/ can he syllabic. However, because lip-rounded consonants strengthen the character of consonantal phonemes, they are not so appropriate. Apart from phonemes, some familiar words also could be almost always syllabic. From the historical perspective, we can say that the position of syllabic consonants is typically the second syllables of two-syllabic words and 1.hat the underlying schwa does not always exist. In terms of the syllable structure, the syllables which include syllabic consonants are totally different from both stressed syllables and the other unstressed syllables.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.97-101
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• 1995

This paper describes a new surface finishing process which uses magnetic abrasive polishing. This is applied to automatic finishing of die & mold surface. Nowadays, most of die & mold meanufaturing procedures have been automated by the introduction of NC machine tool and CAD/CAM system. But the surface finishing of die & mold must be done by hand work of well-skilled workers. Though many attempts were tried in the past 15 years to eliminate this hand work, the automatic finishing of die & mold surface with 3D curvature has not been achieved yet. New magnetic abrasive finishing process is thought as one of the possible methods for the automation of 3D surface finishing. In order to improve the grindability of the method, ultra-high speed and 5-axis machining was introduce. The magnetic abrasive polishing which has adopted these methods was confirmend to improve the efficiencyof die & mold surface finishing.

• 한국언어정보학회지:언어와정보
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• 제3권2호
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• pp.13-30
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• 1999

There have been two opposing views on the structure of the so-called head internal relative construction(HIRC) in Korean/Japanese, i.e., a view that analyzes the HIRC categorially as a nominal projection and functionally as an argument(Kuroda 1992, Watanabe 1992, Hoshi 1996, Jhang 1991/1994, among others) vs. a view that analyzes the HIRC categorially as an adjunct clause and functionally as a non-argument(Murasugi 1994). This paper on the one hand points out several phenomena indicating that Murasugi's analysis is more viable, while on the other hand proposing a more complex structure than Murasugi's to account for other facts as well. The no/kes clause in the HIRC will be analyzed as the complement of a null perception verb whose projection constitutes part of an adjunct clause.

• 한국언어정보학회지:언어와정보
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• 제3권2호
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• pp.1-12
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• 1999

There have been two opposing views on the structure of the so-called head internal relative construction(HIRC) in Korean/Japanese, i.e., a view that analyzes the HIRC categorially as a nominal projection and functionally as an argument(Kuroda 1992, Watanabe 1992, Hoshi 1996, Jhang 1991/1994, among others) vs. a view that analyzes the HIRC categorially as an adjunct clause and functionally as a non-argument(Murasugi 1994). This paper on the one hand points out several phenomena indicating that Murasugi's analysis is more viable, while on the other hand proposing a more complex structure than Murasugi's to account for other facts as well. The no/kes clause in the HIRC will be analyzed as the complement of a null perception verb whose projection constitutes part of an adjunct clause.

• 한국정밀공학회지
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• 제23권7호
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• pp.67-75
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• 2006

One of challenging topics for humanoid hands is to modulate a human-like motion of humanoid fingers handling an object. To this end, recognizing the motion behavior of human fingers is very important aspect. Based on this concept, this paper identifies the .joint trajectories of human fingers for an operation of hand opening and closing, and specifies an empirical model that coordinates an inter-articular relationship of human fingers doing the given motion. It is expected that the inter-articular model presented in this paper is applicable for humanoid fingers to mimic the natural motion of human fingers.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1997년도 한국감성과학회 연차학술대회논문집
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• pp.91-94
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• 1997

Objective of this stuey was to find the corrdlation between emotiona changes and the parameters of HRV spectrum evoked by tactile stimualtion. Twenty-one subjects were useds and five different types of materials, dry cottn, wet cotton, paper, sandpaper, and vinyl were applied to the left hand of each subject as a tactile stimulation. The results showed that HF/LF(ratio of high to low frequency amplitude calculated from power spectrum of HRV) decreased as the subject experienced the unpleasant emotion caused by wet cotton and sandpaper. On the othr hand, when the subject experienced the comfort, HF/LF increased. It was concluded that the proprsed methods can be applied to evaluate the characteristic changes in the autonomic nervous system which regulates the human emotion in the psychological aspects.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.221-228
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• 2006

As Industrialization gets more and more advanced, human technological medical apparatus for dentistry has been developed. Such a medical apparatus have to let precision revolution and torque control facilitate. Consequently, Development of Micro hand-piece with strong durability should be required. Moreover, It's also very important to evaluate performance of such a Micro hand-piece, Evaluation of Mechanical property of Material and ANOVA have been known as useful methods in the field of Quality Evaluation. For Verification of Quality Evaluation, It has been evaluated by One-way layout ANOVA based on the data of Surface Roughness Test. Anyhow, This test has been respectively carried out by 3 kinds of Test and Superior performance has appeared in the Test result.