• Korean Chemical Engineering Research
• /
• v.46 no.1
• /
• pp.15-22
• /
• 2008

Polyolefin block copolymer has been taking a great deal of attention due to their great potential in polymer industry since a new metallocene catalytic method for producing polyolefin block copolymer was developed by Dow Chemicals. However, so far, there was no systematic study of olefin block copolymer. In this review, Linear polyolefin block copolymers, containing semicrystalline poly (ethylene) (E) blocks and a rubbery block as a thermoplastic elastomer, were investigated in the viewpoint of microphase separation mode, microstructure, deformation behavior, and molecular architecture.

• Structural Engineering and Mechanics
• /
• v.45 no.6
• /
• pp.779-802
• /
• 2013

In this paper, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural networks (ANNs) techniques are developed and applied to identify damage in a model steel girder bridge using dynamic parameters. The required data in the form of natural frequencies are obtained from experimental modal analysis. A comparative study is made using the ANNs and ANFIS techniques and results showed that both ANFIS and ANN present good predictions. However the proposed ANFIS architecture using hybrid learning algorithm was found to perform better than the multilayer feedforward ANN which learns using the backpropagation algorithm. This paper also highlights the concept of ANNs and ANFIS followed by the detail presentation of the experimental modal analysis for natural frequencies extraction.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.4
• /
• pp.320-329
• /
• 2016

An implicit method of solving the six degree-of-freedom rigid body motion equations based on the second order Adams-Bashforth-Moulten method was utilised as an improvement over the leapfrog scheme by making modifications to the rigid body motion solver libraries directly. The implementation will depend on predictor-corrector steps still residing within the hybrid Pressure Implicit with Splitting of Operators - Semi-Implicit Method for Pressure Linked Equations (PIMPLE) outer corrector loops to ensure strong coupling between fluid and motion. Aitken's under-relaxation is also introduced in this study to optimise the convergence rate and stability of the coupled solver. The resulting coupled solver ran on a free floating object tutorial test case when converged matches the original solver. It further allows a varying 70%-80% reduction in simulation times compared using a fixed under-relaxation to achieve the required stability.

• Journal of Industrial Technology
• /
• v.27 no.B
• /
• pp.43-51
• /
• 2007

In mobile multi-hop wireless networks, the authentication between a base station and a mobile multi-hop node, between multi-hop nodes, and between user a station and a multi-hop node is needed for the reliable and secure network operation. In this paper, we survey various authentication schemes which can be considered to be adopted in mobile multi-hop wireless networks and propose a concept of novel mutual authentication scheme applicable to mobile multi-hop network architecture. The scheme should resolve the initial trust gain problem of a multi-hop node at its entry to the network, the problem of rogue mobile multi-hop node and the problem of hop-by-hop authentication between multi-hop nodes. Effectively, the scheme is a hybrid scheme of the distributed authentication method and the centralized authentication method which are considered to be deployed in the wireless ad-hoc network and the wireless network connected to wired authentication servers, respectively.

• Korean Journal of Computational Design and Engineering
• /
• v.11 no.5
• /
• pp.365-374
• /
• 2006

The ubiquitous environment is to support people in their everyday life in an inconspicuous and unobtrusive way. This environment requires information such as the person, his/her preferences, and habits which is available in the ubiquitous system. In this paper, we propose the context aware system that can provide the tailored information service for user in ubiquitous computing environment. Our system architecture is divided into 4 domain models such as context awareness, presentation, interface and inference domain. Each domain model can perform some predefined tasks independently. And we suggest the hybrid algorithm combined with fuzzy and Bayesian method in order to reason what is the suitable information for user. We show the possibility for the real application through applying the system to the TGA (Tour Guide Assistant) for Kyoungju historical site.

• KIEAE Journal
• /
• v.2 no.1
• /
• pp.49-54
• /
• 2002

Solar daylighting system provides free and comfort lighting, but its cost has been key issue due to difficult design and control of the heavy light collecting system. One of the solutions for the heavy design issues would be using a light framed film such fresnel and prism lens. Prism light guide luminaires have for some time been used to distribute light when it is desirable to have remote light sources. These systems are helpful when it is desirable to have fewer light sources, and/or to position light sources in places where lamp maintenance is easier, or electrical hazard is reduced. This proposed prototype system consists of light collector, light transformer and light pipe.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2006.10a
• /
• pp.176-183
• /
• 2006

A novel intelligent anti-collision decision-making supporting system is addressed in this paper. To obtain precise anti-collision information capability, an innovative neurofuzzy network is proposed and applied. A fuzzy set interpretation is incorporated into the network design to handle imprecise information. A neural network architecture is used to train the parameters of the Fuzzy Inference System (FIS). The learning process is based on a hybrid learning algorithm and off-line training data. The training data are obtained by trial manoeuvre. This neurofuzzy network can be considered to be a self-learning system with the ability to learn new information adaptively without forgetting old knowledge. This supporting system can decrease ship operators' burden to deal with bridge data and help them to make a precise anti-collision decision.

• Transactions of the Society of Information Storage Systems
• /
• v.9 no.1
• /
• pp.22-27
• /
• 2013

In this paper we are presenting a architecture of Co ion decorated graphene oxide as an electrode for supercapacitor application. Graphene oxide, which is exfoliated by oxidant from graphite, is the material for solving the problem of mass production and coating on the surface of working electrode. The $Co^{2+}$ ions are coated by using layer by layer(LBL) method on graphene oxide foam. The metal ion decorated graphene oxide shows enhanced capacitance performance when tested as supercapacitor electrode, showing the specific capacitance of $827Fg^{-1}$.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2005.11a
• /
• pp.157-162
• /
• 2005

Seamlessness is the Keyword of U-Commerce Which may be defined as the commercial interaction among providers, consumers, products, and services, enabled and supported especially by the real-world seamless communication of each entity and object's digital information. However, the possibility of the seamless transactions increases the privacy risk of the entities involved. Therefore, the core issue of U-Commerce is how to promote seamless transactions while protecting the privacy. for the seamlessness, the role of incentive-emphasized business model is important since the seamlessness makes clear which economic entities contribute to a commercial transaction. Economic entities will reject the seamless transactions unless the sufficient incentives are given to them. In order to consider the privacy issue, we suggest an alternative U-Commerce architecture based on Hybrid P2P Model and Personal Information Base.

• 한국IT서비스학회:학술대회논문집
• /
• 2006.11a
• /
• pp.185-189
• /
• 2006

기존의 레거시 시스템은 개발과정에 있어서 이미 많은 시간과 경험과 지식을 갖고 있기 때문에 조직의 핵심 가치를 지닌 재사용 자산으로 활용할 수 있는 의미있는 자산이다. 그러므로 레거시 시스템에서 사용해 왔던 가치있는 자산들을 웹을 기반으로 한 e-비즈니스 환경에 적용시키고, 다양한 플랫폼에서 사용하기 위한 필요성이 증대되었다. 변화하는 환경에 따라 레거시 시스템을 현대화(Modernization)하는 방법중의 하나로 현재 시스템에서 운용되고 있는 것을 OMG에서 제안한 모델기반아키텍처(MDA)를 사용하여 여러 플랫폼을 쉽게 지원하고 모델기반의 통합을 하고자 한다. MDA 환경을 기반으로 기존의 레거시 시스템을 활용하기 위하여 기존의 소프트웨어를 직접 수정 없이 재사용하거나 PSM에서 PIM 변환을 하기 위하여 래퍼(wrapper를 사용한다. 본 논문에서는 이러한 래퍼의 사용에 따른 문제점을 분석하고, 요구에 따라 모델에 대한 접근방식을 다르게 사용하여 시스템의 개선상황에 유연하게 대처할 수 있도록 래퍼를 상황에 따라 적절하게 사용하는 혼합(hybrid) 방식을 적용한 개선전략을 제안하고자 한다.