• Economic and Environmental Geology
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• v.5 no.4
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• pp.231-239
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• 1972

The central region of South Korea is composed of Precambrian formations and Jurassic Daebo granites and is divided tectonically into three provinces, that is, the Ok chon geosynclinal zone in the middle, the Kyonggi massif on the north and northwest side, and the Ryongnam massif on the south and southeast side. The general trend of the Okchon geosynclinal zone and the distribution of Daebo granites is northeast, the Sinian direction. The Kyonggi massif is composed of Precambrian Y onchon system, Sangwon system, gneisses, and Daebo granites, and the Ryongnam massif also Precambrian Ryongnam and Yulri systems, gneisses, and Daebo granites. Precambrian formations in both areas are of flysch type sediments and may be roughly correlated with each other. These formations except Sangwon and Yulri systems are thought to be early to middle Precambrian age and have acted as basement for the Okchon geosyncline where late Precambrian Okchon system was deposited. The Okchon geosynclinal zone is divided into paleogeosynclinal zone to southwestern parts where the Okchon system is distributed, and neogeosynclinal zone to northeastern parts where nonmetamorphosed Paleozoic sediments are dominantly cropped out. Both zones are separated by upthrust created by Daebo orogeny of Jurassic period, which continues southwesterly to bind the Okchon geosynclinal zone and the Ryongnam massif at southwestern parts bisecting Korea peninsula diagonally. Three periods of structural development are recognized in the area. Folds and faults of preTriassic age prevail in the Kyonggi massif. Many isoclinal folds and thrusts originated by Jurassic Daebo orogeny are aligned in the Okchon paleogeosynclinal zone paralleling to the geosynclinal axis so that same formation appears repeatedly in narrow strips, whereas fold axis in neogeosynclinal zone trerid west-northwesterly which might be of Triassic in age and modified by later Daebo orogeny. Discontinuity of geology and structure of Okchon geosynclinal zone is attributed to shifting of the geosyncline through geologic time.

• Journal of the Korean Mathematical Society
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• v.52 no.3
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• pp.489-501
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• 2015

We study the structure of right duo ring property when it is restricted within the group of units, and introduce the concept of right unit-duo. This newly introduced property is first observed to be not left-right symmetric, and we examine several conditions to ensure the symmetry. Right unit-duo rings are next proved to be Abelian, by help of which the class of noncommutative right unit-duo rings of minimal order is completely determined up to isomorphism. We also investigate some properties of right unit-duo rings which are concerned with annihilating conditions.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.883-885
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• 2005

광대역 통합망에서 방송과 통신기능을 결합한 컨텐츠 소비 환경을 통해 사용자는 컨텐츠 검색, 공유, 발행과 같은 컨텐츠 재분배를 수행해 새로운 컨텐츠 소비 체인을 형성하여 컨텐츠 획득 및 소비에 필요한 도메인을 방송망과 통신망으로 확장한다. 본 논문에서는 디지털 케이블망에 연결되어 방송 뿐 아니라 시청자가 능동적으로 자신이 원하는 컨텐츠를 검색하거나 발행 주체로서의 역할을 수행가능하도록 하는 NDR 플랫폼 개발 중 관련 SW 관점의 설계 및 구현방안에 관해 논한다.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1241-1248
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• 2004

A controller of wheeled mobile robot(WMR) based on Lyapunov theory is designed and a Fuzzy-Neural Network algorithm is applied to this system to adjust controller gain. In conventional controller of WMR that adopts fixed controller gain, controller can not pursuit trajectory perfectly when initial condition of system is changed. Moreover, acquisition of optimal value of controller gain due to variation of initial condition is not easy because it can be get through lots of try and error process. To solve such problem, a Fuzzy-Neural Network algorithm is proposed. The Fuzzy logic adjusts gains to act up to position error and position error rate. And, the Neural Network algorithm optimizes gains according to initial position and initial direction. Computer simulation shows that the proposed Fuzzy-Neural Network controller is effective.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2143-2147
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• 2013

Matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a very effective method for lipid mass fingerprinting. However, MALDI MS suffered from spectral complexities, differential ionization efficiencies, and poor reproducibility when analyzing complex lipid mixtures without prior separation steps. Here, we aimed to find optimal MALDI sample preparation methods which enable selective or class-wide mass fingerprinting of two totally different lipid classes. In order to achieve this, various matrices with additives were tested against the mixture of phosphatidylcholine (PC) and cerebrosides (Cers) which are abundant in animal brain tissues and also of great interests in disease biology. Our results showed that, from complex lipid mixtures, 2,4,6-trihydroxyacetophenone (THAP) with $NaNO_3$ was a useful MALDI matrix for the class-wide fingerprinting of PC and Cers. In contrast, THAP efficiently generated PC-focused profiles and graphene oxide (GO) with $NaNO_3$ provided Cer-only profiles with reduced spectral complexity.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.1-8
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• 2019

The online retail market continues to grow, especially in China, as e-commerce has developed rapidly in recent years in many countries. Meanwhile, the development and use of new network information technology provides consumers with various contact and experience environments for online shopping. Based on the theory of media weakness, the study began to focus consumer experience on the nature of commercial transactions. The study proposed and designed an initial measure of the consumer information evaluation index, which combines previous findings with implications. Finally, the five-dimensional B2C system was established to evaluate consumers' information experience providing information display, information interaction, information support and information personalization. We researched on evaluation index system for information experience of B2C e-commerce consumers based on samples of Chinese consumers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.831-841
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• 2017

This paper presents a secure and DoS-resistant fragment authentication technique for Content-Centric Networking (CCN). Our approach not only guarantees the authenticity of each fragment, but also provides a high resistance to DoS attacks through the immediate verification of fragment authenticity at interim nodes on the routing path. Our experimental results demonstrate that the proposed approach provides much stronger security than the existing approach, without imposing a significant overhead.

• Review of KIISC
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• v.27 no.1
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• pp.18-24
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• 2017

네트워크 기능 가상화(Network Function Virtualization, NFV) 기술은 기존에 물리적인 장비 형태로 제공되던 네트워크 기능들을 소프트웨어로 구현하여 가상의 인스턴스 형태로 제공하는 것을 말한다. 이런 NFV 기술을 통해 가용한 네트워크 자원들의 효율적인 활용과 가변적인 시스템 상황에 대한 유연한 대응이 가능하다. 이러한 NFV 기술이 점차 발전하면서 네트워크 보안 분야에서도 보안 서비스 벤더들이 자신들의 클라우드 시스템을 통해 소프트웨어 기반 다양한 네트워크 보안 기능들을 제공하는 시스템 형태가 점차 나타나고 있다. 본 논문에서는 NFV 기반 네트워크 보안 서비스 제공 시스템을 위한 참고 아키텍처로서 국제 인터넷 기술 표준화 단체인 IETF의 Interface to Network Security Functions (I2NSF) working group에서 제안한 I2NSF 시스템을 소개한다. 그리고 이러한 시스템 모델을 기반으로 NFV 기반 네트워크 보안 서비스 제공 시스템 설계 및 개발 시 고려해야 할 주요 연구이슈들에 관해 논의한다.

• Annual Conference on Human and Language Technology
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• 2017.10a
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• pp.264-266
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• 2017

본 연구는 리마인더 앱을 위한 효과적인 시간 표현 분석 방법을 제안한다. 시간 표현 분석을 위한 정규식 패턴을 이용하여 사용자 발화 텍스트로부터 시간 정보를 분석하고 시간 표현 유형에 따라 절대적 시간 정보로 변환한다. 제안한 방법은 정규식 패턴을 이용한 시간 표현 분석 기법으로 시스템의 유지 관리가 용이하고 정보량이 많은 패턴과의 매칭을 위해 효과적이다.

• Journal of Aerospace System Engineering
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• v.4 no.2
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• pp.21-25
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• 2010

Fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. However, it is very difficult to apply conventional fatigue test loads in short period. Therefore, accelerating test speed and facilitating spectrum load realization are required. In this study, we have developed a fatigue testing method that uses a resonance of simply supported beam type blade specimen. This test consists in exciting the blade specimen with a frequency that corresponds to its natural frequency. In that case, the test specimen similar to a beam fixed between two pivot points starts vibrating and is significantly deformed. Resonant fatigue tests were performed by changing exciting vertical amplitude and frequency, and S-N curves of each composite materials were successfully obtained.