• The Journal of Bigdata
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• v.6 no.2
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• pp.29-38
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• 2021

Deviation of route in aviation safety management is a dangerous factor that can lead to serious accidents. In this study, the anomaly score is calculated by classifying the tracks through clustering and calculating the distance from the cluster center. The study was conducted by extracting tracks within 100 km of the airport from the ADS-B track data received for one year. The wake was vectorized using linear interpolation. Latitude, longitude, and altitude 3D coordinates were used. Through PCA, the dimension was reduced to an axis representing more than 90% of the overall data distribution, and k-means clustering, hierarchical clustering, and PAM techniques were applied. The number of clusters was selected using the silhouette measure, and an abnormality score was calculated by calculating the distance from the cluster center. In this study, we compare the number of clusters for each cluster technique, and evaluate the clustering result through the silhouette measure.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.1
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• pp.85-90
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• 2013

This paper presents a study on terrain referenced navigation (TRN). The extended Kalman filter (EKF) is adopted as a filter method. A Jacobian matrix of measurement equations in the EKF consists of terrain slope terms, and accurate slope estimation is essential to keep filter stability. Two slope estimation methods are proposed in this study. Both methods are based on the least-squares approach. One is planar regression searching the best plane, in the least-squares sense, representing the terrain map over the region, determined by position error covariance. It is shown that the method could provide a more accurate solution than the previously developed linear regression approach, which uses lines rather than a plane in the least-squares measure. The other proposed method is weighted planar regression. Additional weights formed by Gaussian pdf are multiplied in the planar regression, to reflect the actual pdf of the position estimate of EKF. Monte Carlo simulations are conducted, to compare the performance between the previous and two proposed methods, by analyzing the filter properties of divergence probability and convergence speed. It is expected that one of the slope estimation methods could be implemented, after determining which of the filter properties is more significant at each mission.

• Journal of Korean Academy of Nursing Administration
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• v.18 no.3
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• pp.320-328
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• 2012

Purpose: Professional quality of life is the quality one feels in relation to their work as a helper. The purpose of this study was to describe professional quality of life among emergency nurses. Methods: A total of 15 emergency rooms were selected in three cities. Among 263 nurses working at these emergency rooms, 178 nurses consented to participate in this cross-sectional survey. Professional Quality of Life (ProQOL) Scale version 5 was used to measure compassion satisfaction, burnout and secondary traumatic stress. Cluster analysis was used to classify nurses according to professional quality of life. Results: The mean scores (SD) for compassion satisfaction, burnout, and secondary traumatic stress were 32.12 (5.45), 28.27 (4.28), and 28.20 (5.07), respectively. The result of cluster analysis according to standardized score of compassion satisfaction, burnout, and secondary traumatic stress yielded three clusters. Over 50% of participants showed low professional quality of life. Nurses who were included in a cluster representing low professional quality of life were younger, had shorter periods of nursing experience, and perceivedlower social support than other cluster. Conclusion: Education or support programs for emergency nurses are needed to enhance their professional quality of life.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4011-4015
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• 2011

We explored the interpretation of the well-accepted correlation between the apparent peak maximum position shift and extent of molecular interactions, like hydrogen bonding and dipole-dipole interactions, based on the overlapped multiple band model. The simulation of two overlapped Lorentzian bands was carried out to interpret how the maximum position of a composite peak relates to the relative contributions of two species representing the different levels of molecular interactions, i.e., free (or very weekly bound) vs. strongly bound. To demonstrate the validity of our interpretation of the origin of the peak position shift, the temperaturedependent IR spectra of ethylene glycol were also analyzed. It was found through the analysis of simulated and experimental spectra that the apparent peak shift in certain case can be safely interpreted as the measure of the strength of hydrogen bonding. The result of this study gives a new insight to interpret molecular interactions probed by vibrational spectroscopy.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.174-182
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• 1996

In continuous speech recognition system, it is possible to implement the system which can handle unlimited number of words by using limited number of phonetic units such as phonemes. Dividing continuous speech into the string of tems of phonemes prior to recognition process can lower the complexity of the system. But because of the coarticulations between neiboring phonemes, it is very difficult ot extract exactly their boundaries. In this paper, we propose the algorithm ot extract short terms which can represent each phonemes instead of extracting their boundaries. The short terms of lower spectral change and higher spectral chang eare detcted. Then phoneme changes are detected using distance measure with this lower spectral change terms, and hgher spectral change terms are regarded as transition terms or short phoneme terms. Finally lower spectral change terms and the mid-term of higher spectral change terms are regarded s the represent each phonemes. The cepstral coefficients and weighted cepstral distance are used for speech feature and measuring the distance because of less computational complexity, and the speech data used in this experimetn was recoreded at silent and ordinary in-dorr environment. Through the experimental results, the proposed algorithm showed higher performance with less computational complexity comparing with the conventional segmetnation algorithms and it can be applied usefully in phoneme-based continuous speech recognition.

• Journal of the Korean Home Economics Association
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• v.33 no.1
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• pp.211-222
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• 1995

The purpose of this study was to investigate(1) the effects of clothing cues of 20s young man in business suits on the perception of occupational suitability in an office setting and (2) the effect of Perceiver's self-monitoring and sex on the perception of occupational suitability formed by the function of clothing cues. The experimental design of this study was between-subjects 23 factorial design. The experimental materials developed for the study were a set of stimuli and a response scale. The stimuli consisted of 8 color photographs of a young man wearing business suits which were manipulated at two levels for each of three clothing cues (suit color, suit style, necktie color). Each one of eight sub-samples included 14 subjects from 2 perceiver groups by sex. The questionaires used to measure perceivers' responses to the stimuli were constructed in 12 five-point likert scale representing occupational suitability and self-Monitoring was measured by the self-Monitoring Scale by Gangestad adn Snyder. The subjects consisted of 224 male and female college students in Seoul. The data was processed by ANOVA and MCA(Multiple Classification Analysis). The result were as follows: (1) The Clothing cues of young man in business suits(suit color, suit style) partially influenced the occupational suitability. (2) The perception of occupational suitability formed by the clothing cues of a young man in business suits was partially influenced by the perceiver's self-monitoring and sex. Female high self-monitoring group were more affected by the clothing cues than any other groups.

• Korean Journal of Community Nutrition
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• v.6 no.1
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• pp.91-96
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• 2001

The purpose of this study was to identify the determinants of nutrition service utilization in health centers. Utilization of nutrition services for chronic discase were also investigated. Interview survey using questionnaire was conducted to collect the data required for analysis. The study subjects were 300 residents over 40 years of age, and 15 health workers representing health center service personnel in Kypnggi province. A wilcoxon 2-sample test and Kruskal-Wallis test were used to compare the distribution of health centers by health center characteristics and nutrition services. A chi-square test was used to test the association between service utilization and personal variables of the population. A multiple logistic regression analysis was used to measure the relative importance between the variables on service utilization. The results showed that only 10.0% of the study subjects used nutrition services provided by the health centers. Pilot project implementation and location of health centers, as well as educational level of the residents were significant factors influencing the utilization of the nutrition services provided by the health centers. Among the variables, pilot project implementation was the most important factor that influenced the nutrition service utilization in health centers.

• Journal of the Korea Computer Industry Society
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• v.5 no.5
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• pp.747-754
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• 2004

In this paper, we obtain an optimal corpus that can represent its characteristics very well from the baseline corpus which consists of unique 1,566,943 names among company names in a directory assistance serve (114). Two kinds of optimal solutions ared considered to obtain the optimal corpus. The first solution is to find phonetically balanced corpus (PBC), which are the minimum set including all possible triphones in the baseline corpus. The second solution is to find the phonetically distributed corpus (PDC), which is a minimum set representing the frequency characteristics of triphones in the baseline corpus. We can obtain 8,699 words as the PBC and 16,783 words (similarity measure R = 0.92) as PDC, respectively. These corpora can be used for the development of speech recognition and speech synthesis.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.156-165
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• 2010

ESM(Enterprise Security Management) is representing domestic security management, and there is requirement to enhance it. This paper will evaluate quality of ESM products, understand its quality level, and derive method to improvement so as to develop security evaluation model and test methodology which can support quality enhancement. In addition, it presented the performance test cases and evaluation method to measure product's security quality, and to perform research on the judgement method for the results based on appropriate criteria. Developed quality evaluation model is expected perform important role in evaluating and enhancing the quality of intrusion prevention system.

• Journal of Environmental Science International
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• v.11 no.9
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• pp.829-842
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• 2002

The purpose of this study was to design a reliable and valid Likert-type scale to measure nuclear energy attitudes of various groups. 8 tests were applied to the construction of a 26-item long form, a 12-item middle form, and a 6-item short form of the scale. Three scales were field tested on 760 respondents representing a diverse range of subjects. The 26-item scale appeared to be reliable, content valid and construct valid. Scale reliability and homogeneity were evidenced by 0.95 coefficient alpha and positive interitem correlations ranging from 0.18 to 0.74. The results of factor analysis and known-groups comparison revealed that this scale had high validity. Reliability of the middle form and short form were evidenced by coefficient alpha of 0.92 and 0.90 respectively. The long and middle forms were strongly correlated, r-value of 0.98 and the long and short forms were also highly correlated, r-value of 0.93. Consequently, long form, middle form and short form scales were evidenced very reliable and valid in measuring nuclear energy attitudes of various groups in general. They can be used for a variety of purpose of measuring and testing nuclear energy attitude.