• The Journal of the Acoustical Society of Korea
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• 제15권1E호
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• pp.84-88
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• 1996

In this paper, we propose a novel adaptive digital filter for tonal noise cancellation, with a frequency tracking capability. The proposed algorithm not only estimates the magnitude and phase of the tonal disturbance but also tracks its frequency, which changes in quasi-static manner. The algorithm uses the steepest descent method and the instantaneous frequency approach for the phase/magnitude estimation and frequency tracking, respectively. A number of computer simulations have been carried out in order to demonstrate the feasibility of the proposed ANC algorithm under various conditions.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.69-77
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• 1999

Roll profile design in spape rolling with a complex-shaped part depends on the designer's experience, which is general, is acquired through costly trial-and-error process. As a prerequisite for developing a scientific approach to roll profile design, we present a finite element model to simulate 3-D deformation of complex-shaped parts occuring in multi-pass sequence. Demonstrated is the process model's capability to deal with rolling of a complex-shaped part.

• Journal of the Optical Society of Korea
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• 제3권2호
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• pp.69-73
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• 1999

This paper demonstrated the performance of a palladium wire hydrogen sensor based on a fiber Bragg grating as a means of developing a quasi-distributed hydrogen sensor network capable of operating at cryogenic temperatures. The new approach employing a fiber Bragg grating based palladium hydrogen sensor described in this study is advantageous over other traditional hydrogen sensors because of the multiplexing capability of fiber Bragg gratings. The sensitivity of the hydrogen sensor at room temperature is approximately 2.5 times that of the hydrogen sensor at cryogenic temperatures.

• Nuclear Engineering and Technology
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• 제42권3호
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• pp.271-278
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• 2010

While the deterministic lattice physics/depletion codes use leakage-corrected critical spectrum (although approximate due to the B1 buckling search employed), Monte Carlo depletion codes currently in use do not have such a feature in spite of their heterogeneity and continuous-energy modeling capability. This paper describes an approach to Monte Carlo depletion with leakage-corrected critical spectrum derived from first principles. This is based on the concept of albedo eigenvalue treated as weight of the reflected neutron in Monte Carlo simulation.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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• pp.231-238
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• 1997

Many methods have been proposed for achieving optimum performance of structures subjected to earthquake excitation. The conventional approach requires that structures passively resist earthquakes through a combination of strength, deformability, and energy absorption. Base isolation is a technique for mitigating the effects of earthquakes on structures through the introduction of flexibility and energy absorption capability. In this paper, a parametric study of effectiveness of isolation systems with various main structures' properties is carried out through the response spectrum analysis. It is shown that, most base isolators with its longer period and higher damping can significantly reduce the base shear force transmitted to the structures.

• 한국IT서비스학회:학술대회논문집
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• 한국IT서비스학회 2003년도 춘계학술대회
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• pp.647-664
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• 2003

[ $\circ$ ] Enterprise architecture is essential for ROI of e-Enterprise. $\circ$ An architecture is described from business, application, data and technical views and these must be complete and consistent. $\circ$ UML-based CBD is currently the best approach to obtaining architecture-centric, flexible and interoperable systems. $\circt$ Reuse of architecture, components, shared services and app frameworks is key to achieving both quality and productivity. $\circ$ Web service, the NBT, cannot be tapped without the architecting capability. $\circ$ Architects with world-class domain as well as software engineering knowledge are key to success of Korean software industry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.3-6
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• 2004

In this paper, the problem of identifying a time-varying nonlinear system in an adaptive way was considered, whereby the time-varying second-order Volterra series was employed to model the system and the filtered weighted least squares (FWLS) algorithm was utilized for the fast parameter tracking capability with low computational burden. Finally, the performance of the proposed approach was demonstrated by providing some computer simulation results.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1992년도 추계학술대회논문집
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• pp.113-120
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• 1992

In this paper, a mathematical model of learning curve is proposed to study the finger's reaction time. The model is a logarithmic linear type which represents a learning curve appropriately, and parameters are estimated by the linear. The learning coefficient and percentage of a reaction time can be easily computed in the mathematical model. This quantitative approach provides an important information to be used for the working capability qualification for re-employment as well as for the adaptability estimation of aged workers.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.772-776
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• 2004

This paper proposes an interference avoidance approach for Constraint-Based Routing (CBR) algorithm in the Multi-Protocol Label Switching (MPLS) network. The MPLS network itself has a capability of integrating among any layer-3 protocols and any layer-2 protocols of the OSI model. It is based on the label switching technology, which is fast and flexible switching technique using pre-defined Label Switching Paths (LSPs). The MPLS network is a solution for the Traffic Engineering(TE), Quality of Service (QoS), Virtual Private Network (VPN), and Constraint-Based Routing (CBR) issues. According to the MPLS CBR, routing performance requirements are capability for on-line routing, high network throughput, high network utilization, high network scalability, fast rerouting performance, low percentage of call-setup request blocking, and low calculation complexity. There are many previously proposed algorithms such as minimum hop (MH) algorithm, widest shortest path (WSP) algorithm, and minimum interference routing algorithm (MIRA). The MIRA algorithm is currently seemed to be the best solution for the MPLS routing problem in case of selecting a path with minimum interference level. It achieves lower call-setup request blocking, lower interference level, higher network utilization and higher network throughput. However, it suffers from routing calculation complexity which makes it difficult to real task implementation. In this paper, there are three objectives for routing algorithm design, which are minimizing interference levels with other source-destination node pairs, minimizing resource usage by selecting a minimum hop path first, and reducing calculation complexity. The proposed CBR algorithm is based on power factor calculation of total amount of possible path per link and the residual bandwidth in the network. A path with high power factor should be considered as minimum interference path and should be selected for path setup. With the proposed algorithm, all of the three objectives are attained and the approach of selection of a high power factor path could minimize interference level among all source-destination node pairs. The approach of selection of a shortest path from many equal power factor paths approach could minimize the usage of network resource. Then the network has higher resource reservation for future call-setup request. Moreover, the calculation of possible path per link (or interference level indicator) is run only whenever the network topology has been changed. Hence, this approach could reduce routing calculation complexity. The simulation results show that the proposed algorithm has good performance over high network utilization, low call-setup blocking percentage and low routing computation complexity.

• 대한기계학회논문집A
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• 제36권7호
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• pp.805-811
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• 2012

신뢰성 기반 최적설계의 효과적인 수행을 위하여 개발된 단일루프 단일벡터 방법은 신뢰성 해석의 계산과정을 제거함으로써 최적설계 시 발생하는 과도한 계산비용을 줄일 수 있다. 하지만 성능함수의 오목한 정도가 심할 경우, 수렴을 하지 못하고 발산하는 경향을 보인다. 때문에 일반적인 단일루프 단일벡터 방법은 낮은 수렴성과 부정확성 문제를 내포하고 있다. 본 연구에서는 공액경사도법을 이용한 단일루프 단일벡터 방법을 제안한다. 공액경사도법은 이전 반복과정의 최대가능손상점에서 계산된 방향 벡터들을 이용하여 현재 설계점에서의 최대가능손상점을 산출하기 위한 새로운 방향벡터를 구하고 이 방향벡터를 이용하여 현재점에서의 최적화를 수행한다. 이를 다양한 수학예제에 적용하고 다른 방법들과 수치적 성능 비교를 통해 제안한 방법의 유용성을 검증한다. 공액경사도법을 이용한 단일루프 단일벡터 방법은 성능함수 특성에 크게 영향을 받지 않으며 수렴성을 크게 향상시킬 수 있다.