• Journal of Institute of Control, Robotics and Systems
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• v.13 no.10
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• pp.962-969
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• 2007

In this paper, an approach is developed for relative state estimation of satellite formation flying. To estimate relative states of two satellites, the Extended Kalman Filter Algorithm is adopted with the relative distance and speed between two satellites and attitude of satellite for measurements. Numerical simulations are conducted under two circumstances. The first one presents both chief and deputy satellites are orbiting a circular reference orbit around a perfectly spherical Earth model with no disturbing acceleration, in which the elementary relative orbital motion is taken into account. In reality, however, the Earth is not a perfect sphere, but rather an oblate spheroid, and both satellites are under the effect of $J_2$ geopotential disturbance, which causes the relative distance between two satellites to be on the gradual increase. A near-Earth orbit decays as a result of atmospheric drag. In order to remove the modeling error, the second scenario incorporates the effect of the $J_2$ geopotential force, and the atmospheric drag, and the eccentricity in satellite orbit are also considered.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.6
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• pp.462-469
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• 2009

This study suggests a general formula of non-cohesive sediment transport rates for waves and currents which is also valid for wave only or current only condition. On-offshore sediment transport rates with the second order Stokes wave in the shallow water are calculated as the pickup rate times the distance. The formula depicts reasonably that high waves move material offshore, and low waves move material onshore. Also the formula, as is the case the waves with long period tend to move material onshore, shows good results.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.629-637
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• 2001

The objective of this study was to identify the cultural characteristics affecting advertising contents of the consumer products. Hofstedes(1991) five cultural characteristics such as individualism-collectivism, power distance, masculinity-feminity, avoidance of uncertainty, confucian dynamism were used. Ten kinds of consumer products were included and data were collected from France, Japan, Korea, and U. S. during 1999∼2000. All ads were evaluated and compared their cultural characteristics in terms of country, product involvement and usage, and magazine type. ANOVA, Duncan test, and Pearson correlation-coefficient were applied to analyze data. The results were shown as follows: First, most ads tended to be individual, less power oriented, feministic, and showed high tendency of uncertainty avoidance as well as long term confucianism for all the countries. And some cultural characteristics were different among countries. Japan, France, U. S. and Korea in order showed higher individualism and lower power distance. Also Korea and Japan showed relatively short term confucian culture while U. S. and France did ling term perspectives in the ads. Second, product involvement and usage type had a significant impact on the characteristics of individualism-collectivism and feminity-masculinity. That is, product ads of lower involvement and personal use were likely to show individualistic messages and to have more feministic appeals. Third, magazine type had an impact on some cultural characteristics. Womens magazines would have more individualistic, less power oriented, and feministic appeals of ads. In conclusion, global ads should be localized and differentiated in terms of some cultural characteristics and differ depending on product characteristics.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.4
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• pp.255-261
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• 2013

In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.1
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• pp.53-59
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• 2008

In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.

• Journal of KIISE:Software and Applications
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• v.35 no.9
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• pp.547-553
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• 2008

We propose a two-stage document layout segmentation method. At the first stage, as top-down segmentation, morphological distance map algorithm extracts a collection of rectangular regions from a given input image. This preliminary result from the first stage is employed as input parameters for the process of next stage. At the second stage, a machine-learning algorithm is adopted RBF network, one of neural networks based on statistical model, is selected. In order for constructing the hidden layer of RBF network, a data clustering technique bared on the self-organizing property of Kohonen network is utilized. We present a result showing that the supervised neural network, trained by 300 number of sample data, improves the preliminary results of the first stage.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.433-445
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• 2017

This study uses a macro-viewpoint to investigate how female world leaders' clothing behaviors are different by nation and culture. This study conducted a comparative study on clothing behavior by cultural block in order to understand similarities and differences based on Hofstede's cultural dimensions theory. The findings are as follows. First, the clothing styles of female world leaders are categorized into classical suit style, national traditional style, and eclectic style. Second, classic suit style is more often found in countries characterized by high individualism, low power distance index, and low avoidance index. The style represents individual activity and rationality as well as trust towards women acting in men's roles. Third, a national traditional style is found in countries featuring high collectivism, high power distance index, and high uncertainty avoidance index. These countries share a culture that emphasizes harmony with the whole, rather than any one given part; consequently, clothing style represents a national identity (or the roles as a national member) rather than that of the individual level. Fourth, an eclectic clothing style is expressed in a mixture of classical suits and a national traditional style that depends on how much Eastern and Western cultures are reasonably compromised or Eastern tradition and Western culture coexist.

• Journal of the Korean Society of Food Culture
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• v.30 no.4
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• pp.439-446
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• 2015

This study considered network quotient (NQ) of deluxe hotel employees and schematized characteristic attributes of being selected by employees with image through correspondence analysis in terms of cognition degree. Self-administrated questionnaires were completed by employees (292 samples) and data were analysed by frequency, t-test, one-way ANOVA, reliability and correspondence analysis. First, the hotel employees indicated the high average value in "participating in special education or seminar for improving ability ($3.85{\pm}0.76$). Second, as a result of analyzing difference according to gender, the average value in men was higher than in women. It was indicated that the higher age and career lead to a rise even in the average value of relationship index. Third, in consequence of carrying out correspondence analysis in order to prepare image map according to cognition level on relationship index in hotel employees, the measurement item that is placed in the closest distance to the response as saying of not so very was the response as saying of "having a lunch (dinner) engagement twice or three times a week." On the other hand, the response as saying of "tending to have many acquaintances compared to coworkers" was schematized in the close distance to the response as saying of very so.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.2
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• pp.127-131
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• 2009

In the digital waveguide theory, traveling waves are represented by general solution to the wave equation that is second-order linear partial differential equation. The movement of these waves can be implemented using only delay lines. An unit delay in the general digital waveguide describes a sampling time interval. However, in the space-based digital waveguide the unit delay implies the spatial sampling distance. In consideration of these differences between two models, it is known that the space-based digital waveguide model is adequate to synthesize pitch-shifted sounds such as vibrato because the propagation distance can be directly control. In this paper, the time-based digital waveguide model which also synthesizes pitch-shifted sounds is proposed and compared with space-based digital waveguide.

• Journal of Information Technology Applications and Management
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• v.26 no.1
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• pp.53-64
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• 2019

The purpose of this study is to find out the fast delivery route that several drones return a truck again after departing from it for delivery locations at each cluster while the truck goes through the cluster composed of several delivery locations. The main issue is to reduce the total delivery time composed of the delivery time by relatively slow trucks via clusters and the sum of maximum delivery times by relatively fast drones in each cluster. To solve this problem, we use a three-step heuristic approach. First, we cluster the nearby delivery locations with minimal number of clusters satisfying a constraint of drone flight distance to set delivery paths for drones in each cluster. Second, we set an optimal delivery route for a truck through centers of the clusters using the TSP model. Finally, we find out the moved centers of clusters while maintaining the delivery paths for the truck and drones and satisfying the constraint of drone flight. distance in the two-dimensional region to reduce the total delivery time. In order to analyze the effect of this study model according to the change of the number of delivery locations, we developed a R-based simulation prototype and compared the relative efficiency, and performed paired t-test between TSP model and the cluster-based models. This study showed its excellence through this experimentation.