• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.232-238
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• 2003

A health monitoring system becomes a very useful tool to obtain information on long term behavior of the important railway structures such as very long span and special type bridges. It can be also used to give a warning signal to the maintenance engineer when the structure shows abnormal behavior. However, due to long term use and temperature changes, the health monitoring system needs to be calibrated periodically. In this study, calibration and gauge factor readjustment process made for the health monitoring system installed in the railroad bridges and tunnel are reviewed and a few findings are updated. Future work will be concentrated on the long-term analysis of the measurement data and on the database structures so that the assessment of the structure is possible

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.241-246
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• 2013

A classic document clustering technique may incorrectly classify documents into different clusters when documents that should belong to the same cluster do not have any shared terms. Recently, to overcome this problem, internal and external knowledge-based approaches have been used for text document clustering. However, the clustering results of these approaches are influenced by the inherent structure and the topical composition of the documents. Further, the organization of knowledge into an ontology is expensive. In this paper, we propose a new enhanced text document clustering method using non-negative matrix factorization (NMF) and WordNet. The semantic terms extracted as cluster labels by NMF can represent the inherent structure of a document cluster well. The proposed method can also improve the quality of document clustering that uses cluster labels and term weights based on term mutual information of WordNet. The experimental results demonstrate that the proposed method achieves better performance than the other text clustering methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.437-442
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• 2000

An alternative inverse feedback structure for adaptive active control of periodic noise is introduced for systems with nonminimum phase cancellation path. To obtain the inverse model of the nonminimum phase cancellation path, the cancellation path model can be factorized into a minimum phase term and a maximum phase term. The maximum phase term containing unstable zeros makes the inverse model unstable. To avoid the instability, we alter the inverse model of the maximum phase system into an anti-causal FIR one. An LMS predictor estimates the future samples of the noise, which are necessary for causality of both anti-causal FIR approximation for the stable inverse of the maximum phase system and time-delay existing in the cancellation path. The proposed method has a faster convergence behavior and a better transient response than the conventional FX-LMS algorithms with the same internal model control structure since a filtered reference signal is not required. We compare the proposed methods with the conventional methods through simulation studies.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.91-105
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• 2005

Using Campa and Chang's Expectations Hypothesis model, We test the expectations hypothesis in the term structure of volatilities in options on KOSPI 200 by using daily dosing prices from January 1999 to December 2003. In particular, it addresses whether long-dated volatilities are consistent with expected future short-dated volatilities, assuming rational expectation. Our results do not support the expectations hypothesis : long-term volatilities rise relative to short-term volatilities, but the increases are not matched as predicted by the expectations hypothesis. In addition, an increase in the current long-term volatilities relative to the current short-term volatilities is followed by at a random.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.63
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• pp.13-21
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• 2001

The present study compared the two experimental methods on inquiring the image structure of odors: Presenting a stimulus is one, and not presenting a stimulus is the other. For experiment one, five odors were presented, and the subjects were instructed to evaluate the odors on 7-point scale for each of the 25 adjectives. For experiment two, no odor was presented, and the subjects were instructed to perform the pair-wise comparisons for the each pair of two adjectives on their similarities on 7-point scale. The data from the two experiments were analysed and compared using MDS(Multi-Dimensional Scaling), Correlation, Cluster Analysis. The results showed that there was no structural differences between two experimental methods in term of the Image structure of odors. But, minor disparity was found between two methods in terms of density of distribution of the adjectives. It was construed that the difference came from the difference of the memory that was used for each of the experiments; that is, short term memory for experiment one and long-term memory for experiment two.

• Journal of Environmental Policy
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• v.14 no.3
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• pp.41-73
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• 2015

The Korea Emissions Trading System that was launched in Jan. 2015 is expected to be a crucial policy measure to abate domestic $CO_2$ emission. For accomplishing its purpose, prior information on the price discovery process needs to be presented in order to facilitate the trading of spot allowances with different vintages. We develope a customized pricing method for Korean ETS using the concept of term structure and the cost of carry model.

• The Korean Journal of Applied Statistics
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• v.26 no.2
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• pp.253-265
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• 2013

It has been interested in developing useful information variables that are able to predict the future movement of final objects to attain the specific policy and strategic target. Term structure of interest rates is known as an important variable to predict future business and economic activity, yet there is little empirical work on the predictability of future changes in real output. This study attempts to develop the statistical model and examine whether domestic term structure of interest rates can predict variations of future cumulative changes in real growth on a long time horizon.

• Journal of The Geomorphological Association of Korea
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• v.20 no.1
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• pp.75-83
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• 2013

Human-induced modifications in coastal area may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. Morever, engineering structure have been built to stabilize coastal change, these effort impact on other morphologic change. In case of coastal area, there are lack of sediment yield data. This study focus on the tendency of long-term shoreline change, estimate method od sediment discharge which is a major factor of coastal change and adduced to way for considering design load influenced to coastal road.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.95-104
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• 1999

In this paper we propose a fast and precise control algorithm for a mobile robot, which aims at the self-tuning control applying two multi-layered neural networks to the structure of computed torque method. Through this algorithm, the nonlinear terms of external disturbance caused by variable task environments and dynamic model errors are estimated and compensated in real time by a long term neural network which has long learning period to extract the non-linearity globally. A short term neural network which has short teaming period is also used for determining optimal gains of PID compensator in order to come over the high frequency disturbance which is not known a priori, as well as to maintain the stability. To justify the global effectiveness of this algorithm where each of the long term and short term neural networks has its own functions, simulations are peformed. This algorithm can also be utilized to come over the serious shortcoming of neural networks, i.e., inefficiency in real time.

• Culinary science and hospitality research
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• v.23 no.5
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• pp.140-150
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• 2017

The purpose of the study was to provide useful implications for management of dessert cafe by discovering selection attributes for product satisfaction and long-term orientation. Using SPSS 22.0 and AMOS 220 Version, the collected data from customers of dessert cafe in Seoul and metropolitan areas were analyzed for frequency analysis, exploratory factor analysis, confirmatory factor analysis, reliability analysis, and covariance structure analysis. As results of hypothesis verification, firstly, service standard and product diversity had a significant effect on product satisfaction of dessert cafe. Secondly, tastes and nutrients influenced positively long-term orientation of dessert cafe. Meanwhile, service standard, mood, and product diversity did not have a significant effect on long-term orientation. Thirdly, product satisfaction affected positively long-term orientation. The results of the study provided useful implications for management of dessert cafe.