• Phonetics and Speech Sciences
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• v.11 no.2
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• pp.57-64
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• 2019

In this paper, we construct a Korean text-to-speech system using the Merlin toolkit which is an open source system for speech synthesis. In the text-to-speech system, the HMM-based statistical parametric speech synthesis method is widely used, but it is known that the quality of synthesized speech is degraded due to limitations of the acoustic modeling scheme that includes context factors. In this paper, we propose an acoustic modeling architecture that uses deep neural network technique, which shows excellent performance in various fields. Fully connected deep feedforward neural network (DNN), recurrent neural network (RNN), gated recurrent unit (GRU), long short-term memory (LSTM), bidirectional LSTM (BLSTM) are included in the architecture. Experimental results have shown that the performance is improved by including sequence modeling in the architecture, and the architecture with LSTM or BLSTM shows the best performance. It has been also found that inclusion of delta and delta-delta components in the acoustic feature parameters is advantageous for performance improvement.

• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.257-270
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• 2019

Followingthe Four Rivers Project, cyanobacterial blooms have been frequently observed in the upstream of the installed weirs. The aim of this study was to characterize the major environmental factors that are associated with the cyanobacteria dominance in Baekje Weir (Geum River) and Juksan Weir (Youngsan River) based on intensive experiments and systematic data mining methods. The factors related to the cyanobacteria dominance include7-days cumulative rainfall (APRCP7), 7-days averaged flow (Q7day), water temperature (Temp), stratification strength (${\Delta}T$), electronic conductivity (EC), DO, pH, $NO_3-N$, $NH_3-N$, TN, TP, $PO_4-P$, Chl-a, Fe, BOD, COD, TOC, and $SiO_2$. The most highly correlatedfactors to the dominant cyanobacteria were found to be EC, Temp, Q7day, $PO_4-P$ in theBaekje Weir. On the other hand, those dominant in the Juksan Weir were ${\Delta}T$, TOC, Temp, EC and TN. The EC showed a strong correlation with cyanobacteria dominance in both weirs because a high EC represents a persisted low flow condition. The cyanobacteria dominance was as high as 56 % when the EC was equal or greater than $418{\mu}S/cm$ in Baekje Weir. It was as high as 63% when the ${\Delta}T{\geq}2.1^{\circ}C$ in the Juksan Weir. However, nutrients showed a minor correlation with cyanobacteria dominance in both weirs. The results suggest that the cyanobacteria dominate in astate where the water flow rate is low, water temperature is high and thermal stratification is strengthened. Therefore, the improvement of flow regimes is the most important to prevent persistent thermal stratification and formation of cyanobacteria bloom in theBaekje and JuksanWeirs.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1079-1089
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• 2018

The majority of existing studies for quantifying uncertainties in climate change impact assessments suggest only the uncertainties of each stage, and not the total uncertainty and its propagation in the whole procedure. Therefore, this study has proposed a new method, the Uncertainty Delta Method (UDM), which can quantify uncertainties using the variances of projections (as the UDM is derived from the first-order Taylor series expansion), to allow for a comprehensive quantification of uncertainty at each stage and also to provide the levels of uncertainty propagation, as follows: total uncertainty, the level of uncertainty increase at each stage, and the percentage of uncertainty at each stage. For quantifying uncertainties at each stage as well as the total uncertainty, all the stages - two emission scenarios (ES), three Global Climate Models (GCMs), two downscaling techniques, and two hydrological models - of the climate change assessment for water resources are conducted. The total uncertainty took 5.45, and the ESs had the largest uncertainty (4.45). Additionally, uncertainties are propagated stage by stage because of their gradual increase: 5.45 in total uncertainty consisted of 4.45 in emission scenarios, 0.45 in climate models, 0.27 in downscaling techniques, and 0.28 in hydrological models. These results indicate the projection of future water resources can be very different depending on which emission scenarios are selected. Moreover, using Fractional Uncertainty Method (FUM) by Hawkins and Sutton (2009), the major uncertainty contributor (emission scenario: FUM uncertainty 0.52) matched with the results of UDM. Therefore, the UDM proposed by this study can support comprehension and appropriate analysis of the uncertainty surrounding the climate change impact assessment, and make possible a better understanding of the water resources projection for future climate change.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.2
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• pp.102-108
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• 2013

To understand the relationship of growth and water use efficiency (WUE) between superior and inferior families from open-pollinated progenies of P. densiflora, two families (one superior and one inferior families) in two open-pollinated progeny test sites were selected using volume growth at 26 years. And we compared environmental factors and WUE which was calculated from measured ${\delta}^{13}C$ in the wood. The ${\delta}^{13}C$ change during the last 20 years showed steady decrease and same pattern as WUE in the fertile site, while there was an inverse relationship between ${\delta}^{13}C$ and WUE in poor site, indicating an interaction between gene and environment. The superior family showed higher WUE than inferior family in poor site, indicating efficient stomatal control of the former under water stress. Water use efficiency calculated by carbon isotope composition can be used as a selection criterion for drought tolerance families in open-pollinated progenies of P. densiflora.

• 한국해양학회지
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• v.19 no.2
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• pp.153-162
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• 1984

This study was conducted to interpret the relations between the polychaete community and its environments in Kwangyang Bay during July, 1982. The type of sediments in the study area varies from sand to clay and the organic content obtained by ignition was in the ranges of 0.3% to 15.4%. The polychaetes which occurred at 25 stations comprised 70 species representing 63 genera and had an average density of 490 animals/m$\^$2/. The most abundant species were Lagis bocki (20%), Lumbrineris longifolia (10%), Chohe teres (7%), and Sternaspis scutata (5%). The polychaete populations show the highest density in muddy sand sediments and have a tendency to decrease their abundance in finer sediments such as bud and clay. The individual numbers of each feeding type show the same tendency. Kwangyang Bay consists of three distinct characteristic communities, representing different physical and biological factors: delta community, muddy flat community and channel community. Delta community has very poor organisms and seems to be determined by physical factors such as tidal current, and by sediment conditions and seems to be determined by physical factors such as tidal current, and by sediment conditions and by the food availability. Muddy flat community shows more diverse and higher abundance than delta community but seems to be impoverished by the stress of oxygen deficiency in sediments. Channel community has the highest density in the study area and comprises more various feeding types. This is probably due to the supply of allochthonous materials from the Seomjin River and offshore as food, the heterogeneous sediments and some biological interactions within habitats.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.81-93
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• 2013

The objectives were to evaluate the accuracy of shade selection by human visual system(VS) and 2 different colorimeters ($ShadeEye^{(R)}$(SE) and Shadepilot (SP)). Maxillary anterior teeth of 30 volunteers which had no caries or restorations were included in the study. Firstly, the accordance in shade selection by 3 dentists and 2 colorimeters was investigated. Secondly, the color of the teeth were measured by 1 observer's naked eye and 2 colorimeters under different illumination conditions (Sunny versus cloudy day). Additionally testing of inter-observer variability selected colors by 2 novice and 2 experienced dentists were compared. For comparing visual and 2 different colorimeters, SP(60%) showed significantly highest rate of accordance than the visual (23.3%) or SE (16.7%) and lowest mean ${\Delta}E$ ($2.62{\pm}0.74$ versus $3.83{\pm}1.38$;SE or $4.04{\pm}1.61$;VS)(p<0.001). If accuracy of shade selection were measured using VS, the mean ${\Delta}E$ value of cloudy day was higher than that of sunny day ($4.35{\pm}1.70$ versus $3.53{\pm}1.31$; p<0.001). There were no significant difference of the mean ${\Delta}E$ value between sunny and cloudy day in both SE and SP. Inter- observer repeatability was higher in 2 experienced group (73.3%) than novice group (36.7%). The mean ${\Delta}E$ of experienced group was lower than that of novice group ($3.60{\pm}1.47$ versus $4.70{\pm}1.67$; p<0.001). Colorimeters (SE or SP) is more accurate and more reproducible compared with human shade assessment. Using visual system may be limited by cloudy and inexperience of tester, then more experience and using colorimeters may be helpful of raising the accurate repeatability of shade selection.

• Korean journal of food and cookery science
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• v.5 no.1
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• pp.15-21
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• 1989

These experiments were carried out to study the factors affecting quality and textural characteristics in the preparation of artificial gluten meat (AGM). Effects of amounts of ingredients on properties of AGM were summarized as follows: 1. The more amounts of water increased, the higher L and b values became, and AGM, therefore, became bright and yellow in color. The more increased the amount of water, the more decreased shear force, hardness and chewiness, but the water holding capacity increased. The 100% of water added sample approached to raw beef in L value, $\Delta$0E, hardness and chewiness. 2. The mixing ratio of walunt and com oil more affected on color than on texture, and the proper ratio was 30% of walunt and 10% of oil. 3. In the case of interactions of oil and water, water amounts affected more on color, shear force, chewiness and the water holding capacity than on oil. AGM mixed with the ratio of 10% of oil and 100% of water approached to raw beef.

• International Commerce and Information Review
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• v.13 no.3
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• pp.31-53
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• 2011

The purpose of this study is to find out the factors affecting the usage and performance of e-Trade in Chinese Small and Medium-sized Enterprises(SMEs). To achieve the purpose of the study, the research model and hypotheses, depicting the relationship among external factors, internal factors, relationship characteristics, e-Trade usage level, and performance were developed based on the existing literature on e-Trade. To test the significance of the research model and hypotheses, an empirical survey were conducted to the Chinese SMEs in Yangtze River Delta area, which are actively using the e-Trade in their trade processes. According to the result of the statistical analyses on the 85 effective questionnaires from the sample firms, support of the government related institutions(one of the external factors) and CEO's support(one of the internal factors) had significant relationship with e-Trade usage level, but no significant relationship was found between the relationship characteristics and e-Trade usage level. Like the results of the most of the existing literature, e-Trade usage level were formed to significantly affected the e-Trade performance. Finally, based on results of the empirical survey, several implications on the Chinese SME's e-Trade strategies and policy alternatives were proposed as a concluding remark.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.540-547
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• 1993

Backgrounds: The measurement of volume of isoflow has been considered as a sensitive test for detecting small airway diseases showing normal pulmonary function in a routine pulmonary function test. To evaluate the functions of small airway among dust exposed workers, the changes of volume of isoflow were measured and its applicability of managing early stage pneumoconiosis patients was studied. Method: The subjects were 67 male, pneumoconiosis with small opacity and FEV1>80%, FEV1/FVC>75% in spirometry and the controls were 20 male, no dust-exposed office workers. The maximal epiratory volume curves after inhalation of indoor air and $He-O_2$ gas mixtures were measured and ${\Delta}V_{max50},\;{\Delta}V_{max75},\;V_{iso}V/VC$ between the dust exposed and control workers were compaired. Results: 1) There were no significant differences between two group in ${\Delta}V_{max50}$ and ${\Delta}V_{max75}$. But the ratio of $V_{iso}V/VC$ of the subjects was siginificantly higher than that of the control (p<0.01). This study confirms that $V_{iso}V/VC$ is a very useful index in early detection of small airway dysfunction. 2) The ratio of $V_{iso}V/VC$ of the subjects was signigicantly different between only smoker group and mixed group(smoker and nonsmoker). It suggestes that smoking is an important cousative factor of small airway dysfunction. 3) As the profusion of the chest X-ray increased, the rartio of $V_{iso}V/VC$ increased, but no significant difference of $V_{iso}V/VC$ was found between categories of pneumoconiosis. The categories of pneumoconiosis and small airway dysfunction may not be related. 4) No significant relationship was established between the duration of work and the ratio of $V_{iso}V/VC$. Conclusions : It is concluded that the measurement of $V_{iso}V/VC$ is useful to detect small airway dysfuction of early stage pnuemoconiosis patents with small opacities but showing normal pulmonary function in a routine pulmonary function test.

• The Korean Journal of Applied Statistics
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• v.22 no.3
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• pp.617-626
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• 2009

A series of recent papers reported that the inter-gene correlations in Affymetrix microarray data sets were strong and long-ranged, and the assumption of independence or weak dependence among gene expression signals which was often employed without justification was in conflict with actual data. Qui et al. (2005) indicated that applying the nonparametric empirical Bayes method in which test statistics were pooled across genes for performing the statistical inference resulted in the large variance of the number of differentially expressed genes. Qui et al. (2005) attributed this effect to strong and long-ranged inter-gene correlations. Klebanov and Yakovlev (2007) demonstrated that the inter-gene correlations provided a rich source of information rather than being a nuisance in the statistical analysis and they developed, by transforming the original gene expression sequence, a sequence of independent random variables which they referred to as a ${\delta}$-sequence. We note in this report using two cDNA microarray data sets experimented in this country that the strong and long-ranged inter-gene correlations were still valid in cDNA microarray data and also the ${\delta}$-sequence of independence could be derived from the cDNA microarray data. This note suggests that the inter-gene correlations be considered in the future analysis of the cDNA microarray data sets.