• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.2074-2079
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• 2018

Global state space's optimal policy is used for offline controller in the form of table by using Dynamic Programming. If an optimal policy table has a large amount of control data, it is difficult to use the system in a low capacity system. To resolve these problem, controller using the compressed optimal policy table is proposed in this paper. A DCT is used for compression method and the cosine function is used as a basis. The size of cosine function decreased as the frequency increased. In other words, an essential information which is used for restoration is concentrated in the low frequency band and a value of small size that belong to a high frequency band could be discarded by quantization because high frequency's information doesn't have a big effect on restoration. Therefore, memory could be largely reduced by removing the information. The compressed output is stored in memory of embedded system in offline and optimal control input which correspond to state of plant is computed by interpolation with Inverse DCT in online. To verify the performance of the proposed controller, computer simulation was accomplished with a one link inverted pendulum.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.735-746
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• 1999

We design the robust and inherently fault tolerant decetralized$$H^infty$$ filter for the multisensor state estimation problem when there are insufficient priori informations on the statistical properties of external disturbances. For developing the proposed algorithm, an alternative form of suboptimal$$H^infty$$ filter equations are formulated by applying an alternative form of Kalman filter equations to the indefinite inner product space state model of suboptimal$$H^infty$$ filtering problems. The decentralized$$H^infty$$ filter that consists of local and central fusion filters can be designed effciently using the proposed alternative$$H^infty$$ filiter gain equations. The proposed decentralized$$H^infty$$ filter is robust against un-known external disturbances since it bounds the maximum energy gain from the external disturbances to the estimation errors under the prescribed level$$r^2$$ in both local and central fusion filters and is also fault tolerant due to its inherent redundancy. In addition, the central fusion equations between the global and local data can reduce the unnecessary calculation burden effectively. Computer simulations are made to ceritfy the robustness and fault tolerance of the proposed algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.48-56
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• 2005

Predictive filter theory proposed recently can be characterized by inherent advantages of estimating modelling error and overcoming the disadvantage of the Kalman filter theory. A one-step ahead error is minimized to produce optimized filter performance in the form of the predictive filter. The main advantage of this filter lies in the ability to estimate both state vector and system model error. In this paper, attitude estimation results based upon the predictive filter theory is addressed. Mathematical formulation for estimating bias signal is peformed by using the predictive filter theory, and attitude estimation based upon vector observation is presented. From the results of this study, the potential applicability of the predictive filter is highlighted.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.150-160
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• 2000

The french modernist garden of the 1920-30s, significant when studying the history of gardens, has been disregarded in landscape architecture studies. This study aims to review and examine the main characteristics of the French modernist garden in relation to Cubism. In addition this study seeks to recover an unnoticed phase from landscape architecture history and lies in a same thread with studies on the theory of Modernism in landscape architecture. The french modernist garden is closely connected with Cubism, as Cubist garden is a popular synonym for the French modernist garden. used simplified and geometrical forms like Cubist painters. In spacial composition, the French modernist garden offered images of various views in one space, much like the Cubist paintings which showed various aspects of an object simultaneously on the canvas. In the French modernist garden, gorgeous colors and various textures were emphasized, much like the synthetic Cubism. Moreover, in the history of landscape architecture, the state of the French modernist garden which tried to change the traditional gardens into a space more suited to the new life style, is similar to that of Cubism as an art movement in the history of art of the early 20th century.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.152-161
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• 2014

Beijing, the capital city of China, has gradually increased its amount of culture space and has also introduced a diverse range of cultural facilities to improve the satisfaction of its citizens lives. In particular are its art museums, which are a symbol of the urban culture and enrich the cultural life of its citizens and are also expected to play a role as a psychological pivot point. However, in comparison with the characteristics of various ethics, local, and the influence on the museums of China, studies which analyze the exterior of the art museums are not sufficient. This is because previous research has focused too heavily on the interior of the art museums. This paper aims to derive distinction through the analysis of the exterior of several art museums and present design factors and application methodology. This research looks at art museums in China and analyzes the current state of the art museums that have been developed based on the culture of Beijing. Through analyzing the case study of five art museums that have been selected in Beijing we can improve our understanding of Chinese culture space and derive distinct design factors. Distinct factors in the exterior of art museums include connection, culture, geographic features, public, and creation. This study is expected to contribute to that exterior of the art museum will be as a contact zone to form a spatial connection and a cultural symbol that can reflect Beijing's unique culture characteristics.

• Journal of Power Electronics
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• v.6 no.2
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• pp.104-113
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• 2006

Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.

• Advances in aircraft and spacecraft science
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• v.9 no.3
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• pp.263-278
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• 2022

The time-varying structural reliability of an aeroelastic launch vehicle subjected to stochastic parameters is investigated. The launch vehicle structure is under the combined action of several stochastic loads that include aerodynamics, thrust as well as internal combustion pressure. The launch vehicle's main body structural flexibility is modeled via the normal mode shapes of a free-free Euler beam, where the aerodynamic loadings on the vehicle are due to force on each incremental section of the vehicle. The rigid and elastic coupled nonlinear equations of motion are derived following the Lagrangian approach that results in a complete aeroelastic simulation for the prediction of the instantaneous launch vehicle rigid-body motion as well as the body elastic deformations. Reliability analysis has been performed based on two distinct limit state functions, defined as the maximum launch vehicle tip elastic deformation and also the maximum allowable stress occurring along the launch vehicle total length. In this fashion, the time-dependent reliability problem can be converted into an equivalent time-invariant reliability problem. Subsequently, the first-order reliability method, as well as the Monte Carlo simulation schemes, are employed to determine and verify the aeroelastic launch vehicle dynamic failure probability for a given flight time.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.482-491
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• 2011

Pavilion(樓亭) was a Building for rest and scene appreciation in chosun dynasty. This research was to analyze construction method and the structure of Pavilion. The detail objectives of the research was ; First, the location of Pavilion and the layout of facilities were analyzed and composition principle was found. Second, Pavilion were analyzed about dimension, form, constructive method, and structure. Pavilion location was selected on the consideration of natural condition such as configuration of the ground, climate, and scene state. The Length of Building remained until present was about 8~12m, the depth was about average 3~4m. The results of these study can give deep understand of physical structure and help to reconstruct future Pavilion.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.361-368
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• 2009

If we think about the form of housing architecture, we can find a general or typical type has been through the architectural history. because the formal transformation in housing architecture is very difficult. Recently, there are many housing works in powerful ocean state, netherlands that was different from the typical type in the form of housing architecture. This study focusing on the formal characteristics in such works. Such distinctive works in netherlands is the result from an attempt to fulfill the diverse needs of our contemporary society and in an effort to refuse the typical type of the modern architecture. The main purpose of this study is to reveal the meaning of typological transformation in the contemporary' housing architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.575-594
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• 2010

In this study, we propose a space search algorithm (SSA) and then introduce a hybrid optimization of fuzzy inference systems based on SSA and information granulation (IG). In comparison with "conventional" evolutionary algorithms (such as PSO), SSA leads no.t only to better search performance to find global optimization but is also more computationally effective when dealing with the optimization of the fuzzy models. In the hybrid optimization of fuzzy inference system, SSA is exploited to carry out the parametric optimization of the fuzzy model as well as to realize its structural optimization. IG realized with the aid of C-Means clustering helps determine the initial values of the apex parameters of the membership function of fuzzy model. The overall hybrid identification of fuzzy inference systems comes in the form of two optimization mechanisms: structure identification (such as the number of input variables to be used, a specific subset of input variables, the number of membership functions, and polyno.mial type) and parameter identification (viz. the apexes of membership function). The structure identification is developed by SSA and C-Means while the parameter estimation is realized via SSA and a standard least square method. The evaluation of the performance of the proposed model was carried out by using four representative numerical examples such as No.n-linear function, gas furnace, NO.x emission process data, and Mackey-Glass time series. A comparative study of SSA and PSO demonstrates that SSA leads to improved performance both in terms of the quality of the model and the computing time required. The proposed model is also contrasted with the quality of some "conventional" fuzzy models already encountered in the literature.