• Journal of Astronomy and Space Sciences
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• v.39 no.4
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• pp.127-139
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• 2022

Irregular mare patches (IMPs), recently discovered on the Moon, are eruptions of magma on the lunar surface, and their origins are still in question. While prior studies on IMPs have mainly focused on optical image analysis, in this study, an analysis of the characteristics of minerals is performed exemplary for the first time. Modified Gaussian model (MGM) deconvolution was applied to the infrared spectrum to confirm the properties of the mafic mineral. Mafic minerals were analyzed for 6 olivine-rich (Ol-rich) IMPs out of 91 currently reported, and only 4 of them yielded results of significance. All four sites showed more abundance of Fe than Mg, and manifested a weak relationship with Mg-suite rock. However, a problem was discovered during the MGM application process due to pilot implementation. In order to solve this problem, it is required to adjust the MGM initial condition settings more precisely and to increase the signal to noise ratio of the observation data. Moreover, it is necessary to analyze the mineral properties for all IMPs considering minerals other than Ol and utilize them to deduce the origin of the IMPs.

• Journal of the Korean housing association
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• v.17 no.3
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• pp.31-40
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• 2006

The purpose of this study is to grasp the present state of a outdoor space planning and to analysis plan characteristics in based on regional characteristics in Housing complex plan. The analysis result of this study is as follows : first, we know that the right of regional characteristics is appearing variously every research workers. also an analysis about regional characteristics that should be considered in housing complex plan was insufficient. Second, regional characteristics can be classified into 5 factors. These are classified as a context of location, city link, life atmosphere, needs of locals and creation of image. Third, it has originality against other housing complex to graft items connected with 'U contest' on outdoor space planning. Also, it has affirmatively effected on image of Buk-gu and recognition of Dong beyn-dong and Seo beyn-dong. It is get out of the uniform design by a planning based on land and surrounding environment in arrangement and forms. Also residents have the satisfaction and pride in arrangement considering the climate of a region and security of the green space.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.575-584
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• 2017

It is suggested the circuit network to analyze the time response of control system. And it is analyzed the interrelation for classical control and modern control by the transfer function and the state equation. Without complicated integration of state transition equation, it is suggested to possible time response by combining the state transition matrix and the transfer function. A source program is coded to display the time response according to the unit-step and the sinusoidal input. Transient response is analyzed in the unit-step input and phase difference between current and voltage is analyzed in sinusoidal input. As writing the suggested contents in transient response or state-space analysis, it is improved the understanding for control engineering and ability for system design.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.17-30
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• 1988

The aim of this project is to analyze the queueing model with the two types of customers which either can wait unrestrictedly or wait restrictively in the system depending on the condition of service facility unless they may be served immediately. This model consists of the three-dimensional state space and then quasi birth-death process is formulated. The steady-state probabilities and measures of performance of this system are derived by using Matrix Geometric method.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.367-371
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• 2002

I construct a chaotically driven contraction system having some analogy with the information transfer mechanism in the brain system especially from CA1 cell to CA3 cell known from the empirical result. And I consider the properties of the response system on a state space according to the external input into the drive neuron by observing the fractal hierarchical structure. Then I induce the relation between the information about state transition of the chaotic time series and the spatial information on a fractal attractor to confirm the possibility of encoding of time series data to spatial information.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.937-940
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• 1995

The purpose of this paper is to present a nonlinear system identification method, where an adaptive nonlinear recursive state-spare(ANRSS) filter is employed as its filter structure, and a variable step (VS) algorithm is applied as its adaptation law. To demonstrate the validity of the proposed method, some simulation results are included.

• Smart Structures and Systems
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• v.17 no.5
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1566-1577
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• 2018

This paper presents a stability analysis of AC-DC power system feeding a speed controlled DC motor in which this load behaves as a constant power load (CPL). A CPL can significantly degrade power system stability margin. Hence, the stability analysis is very important. The DQ and generalized state-space averaging methods are used to derive the mathematical model suitable for stability issues. The paper analyzes the stability of power systems for both speed control natural frequency and DC-link parameter variations and takes into account controlled speed motor dynamics. However, accurate DC-link filter and DC motor parameters are very important for the stability study of practical systems. According to the measurement errors and a large variation in a DC-link capacitor value, the system identification is needed to provide the accurate parameters. Therefore, the paper also presents the identification of system parameters using the adaptive Tabu search technique. The stability margins can be then predicted via the eigenvalue theorem with the resulting dynamic model. The intensive time-domain simulations and experimental results are used to support the theoretical results.

• The Korean Journal of Applied Statistics
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• v.29 no.6
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• pp.1129-1145
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• 2016

Functional neuro-connectivity is one of the main issues in brain science in the sense that it is closely related to neurodynamics in the brain. In the paper, we choose fMRI as a main form of response data to brain activity due to its high resolution. We review methods for analyzing functional neuro-connectivity assuming that measurements are made on physiological responses to neuron activation. This means that we deal with a state-space and measurement model, where the state-space model is assumed to represent neurodynamics. Analysis methods and their interpretation should vary subject to what was measured. We included analysis results of real fMRI data by applying a high-dimensional autoregressive model, which indicated that different neurodynamics were required for solving different types of geometric problems.

• International Area Studies Review
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• v.13 no.2
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• pp.168-188
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• 2009

Japanese economy suffered from a great recession for one decade between 1993 and 2002, because of the bubble bursting. Recently, a similar situation broke out in the USA and spread throughout the world. This paper investigated the effects of economic policy on the Japanese depression in order to find out how the recession, caused by financial crisis, can be reasonably removed. The analysis of documentary records indicate that there exists an optimum rate in government debt and the point in time of economic policy is decisive. Statistical studies with a VAR model and a State Space Model suggest that government expenditures affect the growth rate of national product but with a short term and it has a time lag of a half year. Income tax has a grievous negative effect on the growth rate with a long term and it works without a time lag. Therefore the increasing of taxation should be put into force very carefully. However private investment is a determinate factor for the recovery of depression.