• Smart Structures and Systems
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• v.19 no.4
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• pp.383-391
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• 2017

In this paper, we investigate the impacts of network topology on the performance of a distributed estimation algorithm, namely combine-then-adaptive (CTA) diffusion LMS, based on the data with or without the assumptions of temporal and spatial independence with noisy links. The study covers different network models, including the regular, small-world, random and scale-free whose the performance is analyzed according to the mean stability, mean-square errors, communication cost (link density) and robustness. Simulation results show that the noisy links do not cause divergence in the networks. Also, among the networks, the scale free network (heterogeneous) has the best performance in the steady state of the mean square deviation (MSD) while the regular is the worst case. The robustness of the networks against the issues like node failure and noisier node conditions is discussed as well as providing some guidelines on the design of a network in real condition such that the qualities of estimations are optimized.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.872-880
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• 2007

For effective management of sediment-related diffuse pollution, it is of utmost importance to estimate spatial variation of sediment transport processes within a catchment. A mathematical model can play a critical role in estimating sediment transport processes at the catchment scale provided that the model structure is appropriate for representing major sediment transport processes of the catchment of interest. This paper introduces a distributed catchment model River Basin Water Quality Simulator (RBWQS) and presents some results of its application to a small rural catchment in Korea. The model has been calibrated and validated for a wet period using hourly hydrographs and sediment concentrations observed at the catchment outlet. Based on the model simulation results, the spatial variation of sediment transport processes across the catchment and the effects of paddy fields and small reservoirs on hydrology and sediment transport have been analyzed at the catchment scale.

• Speech Sciences
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• v.13 no.4
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• pp.127-140
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• 2006

This study examined acoustic characteristics of 900 CV syllables produced by five English native speakers. Those target syllables were produced between the syllable /ba/ twenty times. The syllables were segmented and normalized by the maximum intensity value of each syllable and were divided into consonant or vowel sections by a few visible acoustic criteria. Intensity values were collected at 100 relative time points per syllable. Also, cumulative intensity values and consonant and vowel durations along with the ratio of a consonant to each syllable were measured using Praat scripts. Results showed as follows: Firstly, the consonantal section amounted to a quarter of the syllable in terms of both the cumulative intensity and duration. Secondly, the consonantal ratio by the cumulative intensity was similar to that by the duration. Finally, the sum of the cumulative intensity values in each syllable partially coincided with the consonant order by the current sonority scale. Further studies would be desirable on more reliable acoustical measurements and sophisticated perceptual experiments on the English syllables.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.157-161
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• 2007

Full-scale ferro-concrete building technology came was introduced in Japan in Meiji $35{\sim}40(1902{\sim}1907)$ and heralding the beginning of urban modernization. On the roofs of these new architectural constructions, full-scale rooftop gardens were also developed. We consider that gardens established on the roofs of hotel and department stores created a new, modernized garden culture, which greatly influenced the early modern urban culture of Japan, the drama of which it conceived based on the impression in a rooftop garden is made. In this paper, we discuss the influence of Meiji-Era cultural and technological advances on rooftop gardens constructed during the Taisho $Era(1912{\sim}1926)$, as represented by the gardens of Kobe's Oriental Hotel, Tokyo's Mitsukoshi Department Store and Shimonoseki City's Akita Company. Photographic and print sources are utilized to analyze the design features and temporal changes of these pioneering rooftop gardens, as well as their influence on urban culture.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1033-1035
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• 2003

This study attempts to analyze the potential of global scale NDVI data archive to monitor regional scale droughts. Ten-days maximum value NDVI composite data of the northeast Asia region were acquired for the growing seasons from 1993 to 2003. Two NDVI-derived drought indices (SVI, VCI), reported from previous studies, were applied to the study area. Although the SVI and VCI are mainly developed for monitoring the drought condition at the agriculture crop and grasslands, it turned out that they were also effective to reveal the drought condition over the temperate mixed forest. The drought symptom lasts at least one or two months even after the normal raining begins.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.353-355
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• 2022

We report a case of an 80-year-old Korean man with chronic cerebral paragonimiasis who presented with progressive memory impairment. He suffered from pulmonary paragonimiasis 60 years ago and has been experiencing epilepsy since the age of 45. He began experiencing memory and cognitive deterioration 3 years ago. He visited the neuropsychiatric department of our hospital to check his symptoms and health from a year ago. Contrast-enhanced brain magnetic resonance imaging study revealed calcifications and cystic lesions encompassing the right temporo-occipital region. Encephalomalatic changes were also observed in the right occipital and temporal areas. The anti-Paragonimus specific IgG antibodies in his serum showed a strong positive response. The neuropsychological test results showed a Global Deterioration Scale of 4 and a Clinical Dementia Rating Scale of 1. The chronic cerebral paragonimiasis lesions in the patient's right temporo-occipital region might induce the dementic change.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.641-653
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• 2012

We analyzed two radiocarbon-dated lagoonal sediment cores from Cheonjinho and Ssangho using various biogeochemical methods. As a result, the start times of rice agriculture are estimated to be AD 780 for Cheonjinho and 100 BC for Ssangho. There is a large temporal difference in the beginning of rice agriculture between two study sites even though they are closely located on the coast. This result indicates that pollen records are not sufficient to approximate the start time of rice agriculture accurately. A temporal lag seems to exist between the time when rice agriculture was first introduced and the time when full-scale rice agriculture began in the Yeongdong region, probably because of low agricultural productivity. In both study sites, rice agriculture intensified and slope erosion increased 250 years after full-scale agriculture began. This suggests that intensified rice agriculture resulted in an increased number of inhabitants, settlement expansion to hilly areas, and the consequent deforestation.

• Atmosphere
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• v.18 no.3
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• pp.171-182
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• 2008

In this study, we analyzed the spatial and temporal distribution of wind resources over Korea based on hourly observational data recorded over a period of 5 years from 457 stations belonging to Korea Meteorological Administration (KMA). The surface and 850 hPa wind data obtained from the Korea Local Analysis and Prediction System (KLAPS) and the Regional Data Assimilation and Prediction System (RDAPS) over a period of 1 year are used as supplementary data sources. Wind speed is generally high over seashores, mountains, and islands. In 62 (13.5%) stations, mean wind speeds for 5 years are greater than $3ms^{-1}$. The effects of seasonal wind, land-sea breeze, and mountain-valley winds on wind resources over Korea are evaluated as follows: First, wind is weak during summer, particularly over the Sobaek Mountains. However, over the coastal region of the Gyeongnam-province, strong southwesterly winds are observed during summer owing to monsoon currents. Second, the wind speed decreases during night-time, particularly over the west coast, where the direction of the land breeze is opposite to that of the large-scale westerlies. Third, winds are not always strong over seashores and highly elevated areas. The wind speed is weaker over the seashore of the Gyeonggi-province than over the other seashores. High wind speed has been observed only at 5 stations out of the 22 high-altitude stations. Detailed information on the wind resources conditions at the 21 stations (15 inland stations and 6 island stations) with high wind speed in Korea, such as the mean wind speed, frequency of wind speed available (WSA) for electricity generation, shape and scale parameters of Weibull distribution, constancy of wind direction, and wind power density (WPD), have also been provided. Among total stations in Korea, the best possible wind resources for electricity generation are available at Gosan in Jeju Island (mean wind speed: $7.77ms^{-1}$, WSA: 92.6%, WPD: $683.9Wm^{-2}$) and at Mt. Gudeok in Busan (mean wind speed: $5.66ms^{-1}$, WSA: 91.0%, WPD: $215.7Wm^{-2}$).

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.277-281
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• 2011

In this study, past method and recent method for flood discharge with domestic multi-purpose dams in Korea were compared and analyzed with respect to the scale of watershed. Rainfall depth, temporal distribution, effective rainfall, rainfall-runoff model, parameter estimation and base flow were selected as the principal factors affecting flood discharge and effects on flood discharge were analyzed quantitatively by using sensitivity analysis. The results showed that the flood discharges calculated by past and recent method increased and decreased with a wide range of discharge with respect to the scale of watershed. The reason for decrease of flood discharge is the exchange of temporal distribution pattern of rainfall and the principal reason for increase of flood discharge are the increase of rainfall depth by unusual weather phenomena and the difference of estimation method of parameters of unit hydrograph.

• Ocean and Polar Research
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• v.27 no.2
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• pp.189-195
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• 2005

Several models predict large and potentially abrupt ocean circulation changes due to anthropogenic greenhouse-gas emissions. These circulation changes drive-in the models-considerable oceanic oxygen trend. A sound estimate of the observed oxygen trends can hence be a powerful tool to constrain predictions of future changes in oceanic deepwater formation, heat and carbon dioxide uptake. Estimating decadal scale oxygen trends is, however, a nontrivial task and previous studies have come to contradicting conclusions. One key potential problem is that changes in the historical observation network might introduce considerable errors. Here we estimate the likely magnitude of these errors for a subset of the available observations in the Southern Ocean. We test three common data analysis methods south of Australia and focus on the decadal-scale trends between the 1970's and the 1990's. Specifically, we estimate errors due to sparsely sampled observations using a known signal (the time invariant, temporally averaged, World Ocean Atlas 2001) as a negative control. The crossover analysis and the objective analysis methods are for less prone to spatial sampling location biases than the area averaging method. Subject to numerous caveats, we find that errors due to sparse sampling for the area averaging method are on the order of several micro-moles $kg^{-1}$. for the crossover and the objective analysis method, these errors are much smaller. For the analyzed example, the biases due to changes in the spatial design of the historical observation network are relatively small compared to the tends predicted by many model simulations. This raises the possibility to use historic oxygen trends to constrain model simulations, even in sparsely sampled ocean basins.