• Journal of the Korea Institute of Information Security & Cryptology
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• 제24권1호
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• pp.75-86
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• 2014

Demand for the femtocell is largely credited to the surge in a more always best connected communication conscious public. 3GPP defines new architecture and security requirement for Release 9 to deal with femtocell, Home eNode B referred as HeNB. In this paper, we analyze the HeNB security with respect to mutual authentication, access control, and secure key agreement. Our analysis pointed out that a number of security vulnerabilities have still not been addressed and solved by 3GPP technical specification. These include eavesdropping, man-in-the-middle attack, compromising subscriber access list, and masquerading as valid HeNB. To the best of our knowledge, any related research studying HeNB security was not published before. Towards this end, this paper proposes an improved authentication and key agreement mechanism for HeNB which adopts proxy-signature and proxy-signed proxy-signature. Through our elaborate analysis, we conclude that the proposed not only prevents the various security threats but also accomplishes minimum distance from use-tolerable authentication delay.

• Journal of the Korean Institute of Telematics and Electronics T
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• 제36T권1호
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• pp.71-78
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• 1999

This paper presents a new type of energy generative ER suspension system which does not require external power sources. This is accomplished by converting vibration energy(kinetic energy) into electrical energy. In order to undertake this, an appropriate size of the ER damper is manufactured by incorporation a mechanism which changes the linear motion of the ER damper to the rotary motion. This rotary motion is amplified by gears and activates a generator to produce the electrical energy. The efficiency of energy generation is evaluated and the level of damping force with generated power is also investigated. Then, the ER suspension system is applied to the quarter car model, and its vibration isolation is experimentally evaluated with respect to the piston speed.

• Journal of the Korea Society of Computer and Information
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• 제12권6호
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• pp.1-9
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• 2007

We propose a novel framework for distributed resource management. The framework has the following novel features. First, the resource management system is distributed using resource content information that is characterized by system properties. We argue that a distributed system based on resource content is sufficient to satisfy specific scheduling requests for Quality of Service(QoS) considering workload balance across a grid. Second, the distributed system constructs a hierarchical peer-to-peer network. This peered network provides an efficient message routing mechanism. The simulation results demonstrate that the proposed framework is proficient to satisfy QoS in distributed environment.

• Journal of the Korean Society for Precision Engineering
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• 제18권10호
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• pp.194-199
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• 2001

In this paper, we propose a new locomotive mechanism using impulsive force for microcapsule-type endoscope. It has the compact size for movement in the colon and actuating mechanisms for hi-directional movement. The actuating mechanism resembles a pneumatic cylinder and consists of body, inertia mass(piston). spring. pneumatic source and calve. When valve is ON, the pneumatic impulsive force between piston and body drives them in two opposite direction. As the air in the body is passed away, the contrary movements are occurred by spring reaction. Therefore, the direction of body's motion is determined by the relative magnitude of two opposite impulsive forces, i.e., pneumatic and spring force. The effect of two impulsive forces can simply be controlled by On-Off time of solenoid valve.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.187-189
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• 2005

인터넷 및 분산 환경에서 XML은 애플리케이션 간의 자료 저장 및 자료 교환을 위한 표준으로써, XML 문에 대한 연구가 활발히 진행되고 있다. 따라서 이기종 관계형 데이터베이스 시스템들 간의 메타데이터 및 데이터 교환을 위해 W3C에서 제안한 XML Schema를 사용한다. XML Schema는 평면적 구조인 관계형 데이터베이스 시스템의 메타데이터 및 데이터를 계층적 구조인 XML 문서형식으로 나타낼 수 있는 메커니즘을 가지고 있으며, 다양한 원시 데이터 형식을 지원하여 관계형 데이터베이스 시스템이 제공하는 데이터형식을 충분히 반영할 수 있는 구조를 가지고 있다. 또한 기존의 이질적인 전자상거래 플랫폼을 사용하므로 인해 발생하는 시스템간의 상호 호환 및 운영의 어려움이 있다. 그러나 분산 환경에서 이질적인 특성을 해결하기 위해서 XML을 기반으로 하는 쇼핑몰들의 통합된 정보를 검색할 수 있는 사이트가 등장하고 있어 고객들이 구매하고자 하는 상품에 대한 정보를 보다 쉽게 검색할 수 있도록 각종 쇼핑몰 사이트를 연결하여 통합하는 과정이 진행 중이다. 따라서 상품을 검색할 때 메타데이터를 이용하여 선택에 필요한 정보를 고객에게 제공함으로서 상품을 효율적으로 검색할 수 있다. 따라서 XML기반으로 분산된 이 기증의 시스템들을 온톨로지(Ontology)기반의 메타데이터를 이용하여 상품을 검색할 수 있는 시스템을 제안하고, 온톨로지 기반의 메타데이터 XMDR(eXtended MetaData Registry)을 이용한 상품 검색 시스템을 효율적으로 검색하기 위한 온톨로지 서버 구축에 관한 방법을 제안한다.

• The Journal of the Korea institute of electronic communication sciences
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• 제17권5호
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• pp.783-790
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• 2022

The development of SNS and video platforms provided an opportunity to explode the activation of content production and consumption. However, in the legacy system, due to the host-based location-oriented data transmission, there are inherent limitations in efficient operation and management. As an alternative to this, a Contents Centric Network (CCN) was studied. In this paper, when intermediate nodes located between the information provider and the information requester between the real-time streaming services in the CCN environment move or restrict their use, failure through monitoring of wireless reception strength to solve problems like disconnection of transmission quality at the information consumer. We propose a stable intermediate node management mechanism through active response before occurrence.

• Journal of KIISE:Databases
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• 제27권1호
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• pp.64-78
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• 2000

In this paper, we design and implement a system for managing domain specific thesauri, where object-oriented paradigm is applied to thesaurus construction, concept browsing and query-based reference. This system provides an objected-oriented mechanism to assist domain experts in constructing thesauri; it determines a considerable part of relationship degrees between terms by inheritance and supplies domain experts with information available from a thesaurus being constructed This information is especially useful to enforce consistency between the hierarchies of a thesaurus, each constructed by different experts in different sites through cooperation. It may minimize the burden of domain eIn this paper, we design and implement a system for managing domain specific thesauri, where object oriented paradigm is applied to thesaurus construction, concept browsing and query based reference. This system provides an objected mechanism to assist domain experts in constructing thesauri: it determines a considerable part of relationship degrees between terms by inheritance and supplies domain experts with information available from a thesaurus being constructed. This information is especially useful to enforce consistency between the hierarchies of a thesaurus, each constructed by different experts in different sites through cooperation. It may minimize the burden of domain experts caused from the exhaustive specification of individual relationship. This system also provides an abstracted browsing and a query based reference, which allow users to easily verify thesaurus terms before they are used in usual boolean queries. The verification is made by actively searching for them in the thesaurus. Reference queries and abstracted browsing views facilitate this searching. The facility is indispensable especially when precision counts for much.

• Journal of Korean Tunnelling and Underground Space Association
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• 제19권2호
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• pp.121-141
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• 2017

The thermal analysis of an underground power conduit for electrical cables is essential to determine their current capacity with an increasing number of demands for high-voltage underground cables. The temperature rises around a buried cable, caused by excessive heat dissipation, may increase considerably the thermal resistance of the cables, leading to the danger of "thermal runaway" or damaging to insulators. It is a key design factor to develop the mechanism on thermal behavior of backfilling materials for underground power conduits. With a full-scale field test, a numerical model was developed to estimate the temperature change as well as the thermal resistance existing between an underground power conduit and backfill materials. In comparison with the field test, the numerical model for analyzing thermal behavior depending on density, moisture content and soil constituents is verified by the one-year-long field measurement.

• Journal of the Korea institute for structural maintenance and inspection
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• 제25권1호
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• pp.59-66
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• 2021

The earthquakes are the natural disasters that can cause the most serious damage to civil structures. Therefore, various studies are being conducted to secure the safety of structures against earthquakes. Most studies on the safety or mechanism of civil structures during earthquakes are being conducted based on lab scale test, because real structure tests are impossible when considering the scale of civil structures. The scaling factor proposed by Iai is mainly cited, but when applying the scaling factor proposed by Iai, there are many difficulties in selecting the structural members necessary for the production of the lab scale model. This is because when applying the scaling factor proposed by Iai, the scaling factor must be applied to the elastic modulus, which is the material property of the structure. Therefore, a new method based on Iai's 's similarity law for determining scale factor is applied in this study where the material property of real structure is same as that of lab-scale model. Through the results of this study, it is considered that the characteristics of the structure calculated through the lab scale model test can more accurately reflect the characteristics of the real structure.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 한국표면공학회 2003년도 춘계학술발표회 초록집
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• pp.41-41
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• 2003

텅스텐(W)은 높은 thermal stability 와 process compatibility 및 우수한 corrosion r resistance 둥으로 integrated circuit (IC)의 gate 및 interconnection 둥으로의 활용이 대두되고 있으며, 차세대 thin film transistor liquid crystal display (TFT-LCD)의 gate 및 interconnection m materials 둥으로 사용되고 았다. 그러나, 이러한 장점을 가지고 있는 팅스텐 박막이 실제 공정상에 적용되가 위해서는 건식 식각이 주로 사용되는데, 이는 wet chemical 을 이용한 습식 식각을 사용할 경우 낮은 etch rate, line width 의 감소 및 postetch residue 잔류 동의 문제가 발생하기 때문이다. 또한 W interconnection etching 을 하기 위해서는 높은 텅스텐 박막의 etch rate 과 하부 layer ( (amorphous silicon 또는 poly-SD와의 높은 etch selectivity 가 필수적 이 라 할 수 있다. 그러 나, 지금까지 연구되어온 결과에 따르면 텅스탠과 하부 layer 와의 etch selectivity 는 2 이하로 매우 낮게 관찰되고 았으며, 텅스텐의 etch rate 또한 150nm/min 이하로 낮은 값을 나타내고 있다. 따라서 본 연구에서는 halogen-based inductively coupled plasma 를 이용하여 텅스텐 박막 식각시 여러 가지 첨가 가스에 따른 높은 텅스탠 박막의 etch rate 과 하부 layer 와의 높은 etch s selectivity 를 얻고자 하였으며, 그에 따른 식각 메커니즘에 대하여 알아보고자 하였다. $CF_4/Cl_2$ gas chemistry 에 첨 가 가스로 $N_2$와 Ar을 첨 가할 경 우 텅 스텐 박막과 하부 layer 간의 etch selectivity 증가는 관찰되지 않았으며, 반면에 첨가 가스로 $O_2$를 사용할 경우, $O_2$의 첨가량이 증가함에 따라 etch s selectivity 는 계속적으로 증가렴을 관찰할 수 있었다. 이는 $O_2$ 첨가에 따라 형성되는 WOF4 에 의한 텅스텐의 etch rates 의 감소에 비하여, $Si0_2$ 등의 형성에 의한 poly-Si etch rates 이 더욱 크게 감소하였기 때문으로 사료된다. W 과 poly-Si 의 식각 특성을 이해하기 위하여 X -ray photoelectron spectroscopy (XPS)를 사용하였으며, 식각 전후의 etch depth 를 측정하기 위하여 stylus p pmfilometeT 를 이용하였다.