• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.927-939
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• 2015

It appears that the rapid advance in technology has allowed to broaden the variety of rail systems technology, thereby fostering new business opportunity in rail industry. The direction of rail systems operations is mainly two fold. In one direction, long distance operations between mega cities are pursued with help of high speed trains under development. In the other case, relatively short distance operations for covering intra-city or suburban area are becoming popular. A good example of the latter case is light rail transit (LRT) systems. Due to the short distance operation, it is thus expected that both the development and operation cost for LRT systems be reduced to some extent. The cost reduction desired in there can be gained by scaling down the sizes of both the trains and stations as compared to those of normal rail systems. However, it is not well known how the LRT stations can be scaled down. The objective of this paper is to study on how to slim down the stations (particularly, the functions room) of LRT systems. To achieve the objective, an approach is studied based on a modified method of design structure matrix (DSM). Specifically, using the enhanced DSM method, an integrated architecture is developed for the functions room, in which equipments are housed to perform the functions of electricity, signaling, and communication for LRT stations. The use of the result indicates that the desired reduction can be obtained with the approach taken in the paper.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1080-1091
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• 2003

Recently, the distance education has been rapidly proliferated with the rapid growth of the Internet and high speed networks. There has been relatively much research with regard to online lecture (teaching and studying) tools for the distance education, compared to the virtual laboratory tools (for self-study and experiments). In this paper, we design and implement a web-based simulation tool, named as SimDraw, for the virtual laboratory in the distance education. To apply the web-based simulation technology into the distance education, some requirements should be met; firstly, the user interface of the simulation should be very easy for students. Secondly, the simulation should be very portable to be run on various computer systems of remote students. Finally, the simulation program on remote computers should be very thin so that students can easily install the program onto their computers. To meet these requirements, SimDraw adopts the client/server architecture; the client program contains only model development and animation functions so that no installation of a client program onto student's system is required, and it can be implemented by a Java applet in Web browsers. The server program supports client programs by offering the functions such as remote compiling, model storing, library management, and user management. For the evaluation of SimDraw, we show the simulation process using the example experimentation of the RIP(Routing Information Protocol) Internet routing protocol.

• Structural Engineering and Mechanics
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• v.44 no.2
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• pp.179-196
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• 2012

An eigenspace projection clustering method is proposed for structural damage detection by combining projection algorithm and fuzzy clustering technique. The integrated procedure includes data selection, data normalization, projection, damage feature extraction, and clustering algorithm to structural damage assessment. The frequency response functions (FRFs) of the healthy and the damaged structure are used as initial data, median values of the projections are considered as damage features, and the fuzzy c-means (FCM) algorithm are used to categorize these features. The performance of the proposed method has been validated using a three-story frame structure built and tested by Los Alamos National Laboratory, USA. Two projection algorithms, namely principal component analysis (PCA) and kernel principal component analysis (KPCA), are compared for better extraction of damage features, further six kinds of distances adopted in FCM process are studied and discussed. The illustrated results reveal that the distance selection depends on the distribution of features. For the optimal choice of projections, it is recommended that the Cosine distance is used for the PCA while the Seuclidean distance and the Cityblock distance suitably used for the KPCA. The PCA method is recommended when a large amount of data need to be processed due to its higher correct decisions and less computational costs.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.421-424
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• 2009

The $JHK_S$ magnitudes of the red giant branch tip (TRGB) and the distance moduli of the nearby dwarf irregular galaxy IC 1613 have been determined from the near-infrared luminosity functions (LFs) of the resolved stars in the galaxy. Applying a Savitzky-Golay filtering, we derived the second derivatives of the LFs, and estimated the apparent magnitudes of the TRGB as $m_J\;=\;19.1$, $m_H\;=\;18.4$, and $m_{Ks}\;=\;18.0$. The mean values of the theoretical absolute magnitudes of the TRGB were measured by using the Yonsei-Yale isochrones with a metallicity range of -2.1 < [Fe/H] < -0.5 and age of 12 Gyr. The derived values of near-infrared TRGB distance moduli for IC 1613 are (m - M) = $24.12{\pm}0.25$, $24.20{\pm}0.44$, and $24.00{\pm}0.52$ for J, H, and $K_S$ bands, respectively.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.2
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• pp.121-133
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• 2003

This paper presents a fault location algorithm for a single phase-to-ground fault on 3-terminal transmission systems. The method uses only the local end voltage and current signals. Other currents used for the algorithm are estimated by current distribution factors and the local end current. Negative sequence current is used to remove the effect of load current. Five distance equations based on Kirchhoff's voltage law are established for the location algorithm which can be applied to a parallel transmission line having a teed circuit. Separating the real and imaginary parts of each distance equation, final nonlinear equations that are functions of the fault location can be obtained. The Newton-Raphson method is then applied to calculate the estimated fault location. Among the solutions, a correct fault distance is selected by the conditions of the existence of solution. With the results of extensive S/W and H/W simulation tests, it was verified that the proposed algorithm can estimate an accurate fault distance in a 154kV model system.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.12
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• pp.49-54
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• 2018

Applying metric(distance) factor as weighting to spatial syntax is known to not contribute to the explanatory power for the human movement behavior as compared to the geometric(angle) factor according to the negative results of several related studies. However, Kim & Piao (2017) assumed that there is not a problem of the metric factor itself but a problem of the way of applying the metric factor as weighting, and presented a new possibility of the metric factor as weighting by proposing and verifying the methods of applying the metric weighting, which are different from the existing ones. The purpose of this study is to propose advanced methods of applying the metric weighting to space syntax, and to verify whether they contribute to the improvement of explanatory power of space syntax analysis. In this paper, we propose functions for combined depth of distance-step that combine the distance-weighted depth function with the step depth function and apply them to axial segment analysis to check the improvement of explanatory power of them.

• Journal of Periodontal and Implant Science
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• v.45 no.6
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• pp.216-222
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• 2015

Purpose: After extraction, the alveolar bone tends to undergo atrophy in three-dimensions. The amount of alveolar bone loss in the horizontal dimension has been reported to be greater than the amount of bone loss in the vertical dimension, and is most pronounced in the buccal aspect. The aim of this study was to monitor the predictive alveolar bone level following the extraction of anterior teeth seriously involved with advanced chronic periodontitis. Methods: This study included 25 patients with advanced chronic periodontitis, whose maxillary anterior teeth had been extracted due to extensive attachment loss more than one year before the study. Periapical radiographs were analyzed to assess the vertical level of alveolar bone surrounding the edentulous area. An imaginary line connecting the mesial and the distal ends of the alveolar crest facing the adjacent tooth was arbitrarily created. Several representative coordinates were established in the horizontal direction, and the vertical distance from the imaginary line to the alveolar crest was measured at each coordinate for each patient using image analysis software. Regression functions predicting the vertical level of the alveolar bone in the maxillary anterior edentulous area were identified for each patient. Results: The regression functions demonstrated a tendency to converge to parabolic shapes. The predicted maximum distance between the imaginary line and the alveolar bone calculated using the regression function was $1.43{\pm}0.65mm$. No significant differences were found between the expected and actual maximum distances. Likewise, the predicted and actual maximum horizontal distances did not show any significant differences. The distance from the alveolar bone crest to the imaginary lines was not influenced by the mesio-distal spans of the edentulous area. Conclusions: After extraction, the vertical level of the alveolar ridge increased to become closer to the reference line connecting the mesial and distal alveolar crests.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.2
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• pp.163-170
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• 2011

An optimal layout condition of the offshore wind turbines is studied by using the response surface analysis which is a kind of the design of experiments. Based on the assumption that total 36 turbines would be installed in the offshore wind farm, the number and distance of the rows and columns are used as the design variables and the efficiency decrease of power generation due to the wake decay by the interactions of turbines and the installation cost of the internal electric grid are considered as the objective functions of the response surface analysis for the layout design of turbines. Useful design information can be derived by analyzing the relationship between the design variables and target functions. It is found that the row number and the distance between rows should be minimized, and the optimal distance between columns should be estimated and adopted to the layout design within the specified design range in order to ensure the economics for the offshore wind farm.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.133-143
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• 2007

Previous studies on the transit assignment hardly show its achievement in research but have many limitations not only in theory but also in practice. This paper presents an integrated transit assignment model taking into account cost functions of multiple modes, such as auto, bus and subway, which represent an integrated network. An integrated transit network including cost functions and in-vehicle congestion needs to be developed. In addition, a link fare calculation model needs to be developed and applied to the model to calculate path travel costs. Based on these sub-models, a path-based traffic assignment model, which considers in-vehicle congestion and an integrated distance-based fare system in the integrated traffic network, is developed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.126-134
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• 1990

In this study, eight function discrimination and recognition of the EMG signal from the biceps and triceps of 4 subjects were executed, using the Euclidean and weighted cepstral distance measure with LPC cepstrum coefficients. In case of Euclidean cepstral distance measure, as the number of LPC cepstrum coefficients was increased in 8, 10, 12, 14 the recognition rates of functions are 94.69, 95.63, 96.56, and 96.88[%], respectively, but increasing rates of recognition were inclined to decrease. In case of weighted cepstral distance measure, when the number of LPC cepstrum coefficients was 8, 10, 12 and 14, the recognition rates of functions were 91.88, 95, 99.69, and 96.63[%], respectively.