• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.533-535
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• 2003

The Euclidean distance is sensitive to the absolute offsets of time sequences, so it is not a suitable similarity measure in terms of shape. In this paper. we propose an indexing scheme for efficient matching and retrieval of time sequences based on the minimum distance. The minimum distance can give a better estimation of similarity in shape between two time sequences. Our indexing scheme can match time sequences of similar shapes irrespective of their vortical positions and guarantees no false dismissals

• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.501-510
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• 1999

In this paper, we consider a comparable study on three Bayes procedures for the multivariate normal mean estimation problem. In specific we consider hierarchical Bayes empirical Bayes and robust Bayes estimators for the normal means. Then three procedures are compared in terms of the four comparison criteria(i.e. Average Relative Bias (ARB) Average Squared Relative Bias (ASRB) Average Absolute Bias(AAB) Average Squared Deviation (ASD) using the real data set.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.451-453
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• 2005

In this paper, a preamble structure and a timing synchronization method for 802.16e based system are developed. The performances of the timing offset estimation in multipath fading channel is compared in terms of absolute mean. The simulation result shows that the proposed method has smaller mean.

• Journal of the Korean Statistical Society
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• v.27 no.3
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• pp.349-358
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• 1998

Consider the AR(1) model $X_{t}$=$\beta$ $X_{t-1}$+$\varepsilon$$_{t}$ where $\beta$ < 1 is an unknown parameter to be estimated and {$\varepsilon$$_{t}$} denotes the independent and identically distributed error terms with unknown common distribution function F. In this paper, a strong representation for the least absolute deviation (LAD) estimate of $\beta$ in AR(1) models is obtained under some mild conditions on F. on F.F.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.97-100
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• 2006

This study performed numerical analysis for obtaining optimal frequency and damping ratio of tuned mass damper (TMD) using 20 seismic loads measured at rock site. The structures of $1{\sim}2$ second natural period were considered, and optimal frequency and damping ratio were estimated for different mass ratio in terms of displacement and absolute acceleration response control. Numerical results showed that the values of the optimal parameters were different those from previous study by Hartog.

• Journal of the Korean Statistical Society
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• v.11 no.1
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• pp.45-58
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• 1982

The problem of comparing k normal populations with a control (or a standard) in terms of the absolute values of their means is considered. Under the framework of indifference-zone formulation a single-state and a two-stage procedures for selecting the best are proposed, according to their commom vairances known or unknown respectively. The procedures guarantee that the probability of correct selection is not less than some preassigned lower limit. Selected tables necessary to implement the procedures are provided.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.615-622
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• 2006

The purpose of this study was to analyze the village groves in Pohang city by classifying them into 5 categories: sage plantation, shelter-belt plantation, shore plantation, ornamental plantation and bower plantation. The results of this study can be summarized as follows; The village groves in Pohang city consist of 16 sage plantations ($128,682m^2$), 14 shelter-belt plantations ($807,755 m^2$), 17 shore plantations ($447,616m^2$), 10 ornamental plantations ($141,276m^2$) and 6 bower plantations ($79,075 m^2$). Namely, the ratio of shore plantations is highest (n=17) in terms of number, while that of shelter-belt plantations is highest (50.3%) in terms of area. On the other hand, Pinus Thunbergii account for the absolute majority (n=55,239, 74.1 %) of the trees, followed by pine trees (n=18,017, 24.2%). Both species are combined to account for 98.3% of the entire trees, which means that the plantations are simple in terms of tree species When the village groves were compared in terms of functional age, sage plantations are oldest or aged 143 years, followed by bower plantations (aged 137), ornamental plantations (aged 118), shore plantations (aged 92) and shelter-belt plantations (aged 88).

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.75-81
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• 2000

To provide the appropriate direction for development of transient control in a gasoline engine, transient performance analysis and evalution under four accelerating types based on typical driver's acceleration type were implemented by experimental study. In order to evaluate the characteristics of transient performance quanititatively, the concept and method by transient response specifications were introduced. Several performance parameters in terms of engine speed(RPM), manifold absolute pressure(MAP), fuel injection duration($\DeltatI_{nj}$) and air excess ratio($\lambda$) were emasured simultaneously during the four types of the throttle valve opening with the step motor controlled by PC. The result showed that transient response specifications in terms of delay time, rising time and settling time characterized the transient performance for four acceleration types quantitatively. Intensified acceleration type was most economical and linear acceleration type revealed the best emission performance.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.334-343
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• 1995

In recent years, neural networks have been developed as an alternative to traditional statistical techniques. In this study, a neural network model was compared to traditional forecasting models in terms of their capabilities to forecast passenger traffic for flights between U.S. and Korea. The results show that the forecasting ability of the neural networks was superior to the traditional models. In terms of accuracy, the performance of the neural networks was quite encouraging. Using mean absolute deviation, the neural network performed best. The new technique is easy to learn and apply with commercial neural network software. Therefore, airline decision makers should benefit from using neural networks in forecasting passenger loads.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.350-353
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• 1994

This paper presents a method to calculate the characteristic root areas and loci band of control systems with uncertainties. First, equations of boundary curves of root areas in the case of additive and multiplicative perturbation are derived. Then, an algorithm for the calculation of the array of closed curves is presented. When the upper bound of the absolute values of frequency responses for the uncertain part, is also frequency-dependent, the frequency-dependent, terms are included in the characteristic equation of the nominal system. This lead to the boundary equations of the root, areas for control systems with frequency-dependent uncertainty. Numerical examples of the control systems with multiplicative perturbations including frequency-dependent terms are presented to verify this calculation method. Finally, its applications to the design of robust control systems, e.g., passive adaptive control systems are also discussed.