• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.542-547
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• 2003

A new approach to design of a discrete-time robust $H_{\infty}$ filter in finite horizon case is proposed. It is shown that robust $H_{\infty}$ filtering problem can be cast into the minimization problem of an indefinite quadratic form, which can be solved by implementing the Kalman filter defined in Krein space. The proposed filter is readily derived by simply augmenting the state space model and has the robustness property against the parameter uncertainties of a given system.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1991.09a
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• pp.29-40
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• 1991

The purpose of this study is invested, recorded about traditional dwelling space, and there is to find out possibilites on the context of the inheritance of traditional life through analzing about life content and space. The results of this study are as follows: 1) Kwang Duk vililage is the typical traditional town where the confucian view of life still affects on overall housing life. 2) The pattern of layout is mainly 'ㅡ' and 'ㄱ' shaped type. In the plane and structural form, the original form is, though some parts have changed, maintained. 3) According to the analysis of transformation state of dwelling space, the category of transformation is summerized as follow ; changes of room function, increase and decrease of annex, and room size by changes of family structure, life style, farming operation style.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.572-577
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• 1992

In this paper, the optimal homing guidance problem is investigated for the general missile/target models described in the state-space. The closed-form solution of the optimal guidance law derived, and its asymptotic properties are studied as the time-to-go goes to infinity or zero. Futhermore, several approximate solutions of the optimal guidance law are suggested for real-time applications.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.3
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• pp.69-77
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• 2011

This study considered the characteristic through the present state of domestic literature museum and grouping by type to help the understanding for domestic literature museum. And conducted a case study on Gyeongsang-do region literature museum to grasp the space form composition characteristic of literature museum. The result gained through these studies is as follows. First, grouping domestic literature museum by type, we can conduct the classification founded on location character, an exhibition writer, and the main body of erection and maintenance management. Second, the classification founded on location character of literature museum is able to be divided into the type of the house of writer's birth, a literary work, writing, and etc. Third, the classification founded on the number of exhibition writers can be divided into the type of independence, an individual pavilion, and integration. Fourthly, the classification founded on the main body of erection and management can be divided into the case in which a local self-governing body is wholly in charge of erection and management, a local government is in charge of erection but entrusts management to a corporate body, etc., a corporate body is in charge of erection and management, and a private person is in charge of erection and management. Fifthly, speaking of the characteristic by type of the Gyeongsang-do region literature museum, the classification founded on location has the type of the house of writer's birth the most, the classification founded on the number of exhibition writers has the type of independence the most, and the classification founded on the main body of erection and management has the most the type in which a local self-governing body is in charge of erection and management. Also, for the characteristic by space form, the case which expresses the character of Korean traditional architecture by form is many the most, and there are pieces of work to pursue shape beauty through the articulation of mass or molding manipulation and the change by space form through the proper combination of concreteness and abstraction as well.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.1 no.1
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• pp.35-43
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• 2001

In this paper, we propose a design method for GBSB (generalized brain-state-in-a-box) based associative memories. Based on the theoretical investigation about the properties of GBSB, we parameterize the solution space utilizing the limited number of parameters sufficient to represent the solution space and appropriate to be searched. Next we formulate the problem of finding a GBSB that can store the given pattern as stable states in the form of constrained optimization problems. Finally, we transform the constrained optimization problem into a SDP(semidefinite program), which can be solved by recently developed interior point methods. The applicability of the proposed method is illustrated via design examples.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1927-1934
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• 2018

In this paper, we studied the state of charge (SOC) estimation algorithm of a high-capacity lithium secondary battery for electric vehicles (EVs) considering temperature characteristics. Nonlinear characteristics of high-capacity lithium secondary batteries are represented by differential equations in the mathematical form and expressed by the state space equation through battery modeling to extract the characteristic parameters of the lithium secondary battery. Charging and discharging equipment were used to perform characteristic tests for the extraction of parameters of lithium secondary batteries at various temperatures. An extended Kalman filter (EKF) algorithm, a state observer, was used to estimate the state of the battery. The battery capacity and internal resistance of the high-capacity lithium secondary battery were investigated through battery modeling. The proposed modeling was applied to the battery pack for EVs to estimate the state of the battery. We confirmed the feasibility of the proposed study by comparing the estimated SOC values and the SOC values from the experiment. The proposed method using the EKF is expected to be highly applicable in estimating the state of the high-capacity rechargeable lithium battery pack for electric vehicles.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.6
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• pp.577-588
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• 2016

Due to the uncertainties related to the flaw assessment parameters, such as flaw size, fracture toughness, loading spectrum and so on, the probability concept is preferred over deterministic one in flaw assessment. In this study, efforts have been made to develop the reliability based flaw assessment procedure which combines the flaw assessment procedure of BS7910 and first-and second-order reliability methods (FORM/SORM). Both crack length and depth of semi-elliptical surface crack at weld toe were handled as random variable whose probability distribution was defined as Gaussian with certain means and standard deviations. Then the limit state functions from static rupture and fatigue perspective were estimated using FORM and SORM in joint probability space of crack depth and length. The validity of predicted limit state functions were checked by comparing it with those obtained by Monte Carlo simulation. It was confirmed that the developed methodology worked perfectly in predicting the limit state functions without time-consuming Monte Carlo simulation.

• Korean Institute of Interior Design Journal
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• no.22
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• pp.61-68
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• 2000

This paper illustrates what the reality of architectural concepts, materials, notions and phenomena are as central questions of contemporay space design. These issues form the goal of modern space design which should attain to the reality of an era when non-real values prevail. Despite the trends of an everchanging and ephemeral dominating quality in architecture for the last ten years, architects still aim to contruct everlasting space on earth. The trends of dematerialization in today's space design can be substantiated in spatial-temporal dimensions as follows. First of all, ephemeral architecture with concepts of hypothetical temporality, everchanging architecture in fluidity, and the transparent architecture with the floating and overlapping image can be analyzed in the dimension of 'time'. In terms of 'space', void quality for the expression of emptiness, neutral space by the simplified and summarized forms, expanded space through ambiguous boundaries and spatial repetition can becharacterized and also be intended strategies for lightness, state of flux, ambiguity, paradox etc., lead modern space design along that path. As this point, we need to pay attention to the so-called 'hypersurface' concept proposed by Stephen Perella. Hypersurface is a sort of cladding sheathing existence independent from the primary structure. With it, the integration between form and image can be achieved. Sometimes hypersurface can be a strategical screen for image projection, a cognitive receptor for surroundings as well as a catalyst for information and communication systems. When the situation dematerializes more and more as the years go on, the concept of hypersurface can be an inclusive method between the phenomenological form in architecture and its self recipient image. Permissive atmospheres created between them in contemporary space design and new paradigms emerged with digital technology will further reinforce the human space's dynamism.

• Korean Journal of Remote Sensing
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• v.21 no.1
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• pp.51-57
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• 2005

The currently operating NASA/GFZ Gravity Recovery and Climate Experiment (GRACE) mission is designed to measure small mass changes over a large spatial scale, including the mapping of continental water storage changes and other geophysical signals in the form of monthly temporal gravity field. The European Space Agency's Gravity field and steady state Ocean Circulation Explorer (GOCE) space gravity gradiometer (SGG) mission is anticipated to determine the mean Earth gravity field with an unprecedented geoid accuracy of several cm (rms) with wavelength of 130km or longer. In this paper, we present a summary of present GRACE studies for the recovery of hydrological signals in the Amazon basin using alternative processing and filtering techniques, and local inversion to enhance the temporal and spatial resolutions by two-folds or better. Simulation studies for the potential GRACE detection of slow deformations due to Nazca-South America plate convergence and glacial isostatic adjustment (GIA) signals show that these signals are at present difficult to detect without long-term data averaging and further improvement of GRACE measurement accuracy.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.381-385
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• 1992

In this paper, dynamic modeling and adaptive control problems for a space robot system are discussed. The space robot consist of a robot manipulator mounted on a free-floating base where no attitude control is applied. Using an extended robot model, the entire space robot can be viewed as an under-actuated robot system. Based on nonlinear control theory, the extended space robot model can then be decomposed into two subsystems: one is input-output exactly linearizable, and the other is unlinearizable and represents an internal dynamics. With this decomposition, a normal form-augmentation approach and an augmented state-feedback control are proposed to facilitate the design of adaptive control for the space robot system against parameter uncertainty, unknown dynamics and unmodeled payload in space applications. We demonstrate that under certain conditions, the entire space robot can be represented as a full-actuated robot system to avoid the inclusion of internal dynamics. Based on the dynamic model, we propose an adaptive control scheme using Cartesian space representation and demonstrate its validity and design procedure by a simulation study.