• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.307-312
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• 2014

Wild boar have increased in recent years in Korea where damage to agricultural crops is considered as a social issue. The ecological studies on wild boar are essential for the effective management in the future. During May and December 2012, We collected 79 wild boar stomach samples from culling program implementation to reduce agricultural damage in Geochang County and analyzed stomach contents to figure out wild boar diet habit and which crop was preferred. There was seasonal variation in the diet. Plant foods represented up to 93.5% of the diet and were consumed more frequently than animal foods. Invertebrates occurred with high frequency but were underestimated in dry weight because they are rapidly digested. Agricultural crops consumed comprised mainly chestnuts(33%), rice(33%), and apples(24%). Agricultural crops are also a potentially important food resources for wild boar. The frequency of occurrence of earthworms was 50% of diet. Earthworm consumption generally increased in summer, and then decreased in winter. Our results show that wild boar can be considered an omnivore whose diet consists of plant and animal foods. To reduce wild boar agricultural damages, We have to focus on the prevention effort to rice paddy adjacent to chestnut forest and to apple orchard.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.119-131
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• 2010

Drought is one of disaster causing factors to produce severe damage in the World because drought is destroyed to the ecosystem as well as to make difficult the economy of the drought area. This study, using Palmer Drought Severity Index carries out correlation analysis with sea surface temperatures. Comparative analysis carries out by calculated Palmer Drought Severity Index and past drought occurrence year. Result of comparative analysis, PDSI indexes were in accord with the past drought. Cluster analysis for correlation analysis carries out using precipitation and temperature that is input datas palmer drought severity index, and the result of cluster analysis was classified as 6. Also, principal component carries out using result of cluster analysis. 14 principal component analyze out through principal component analysis. Using analyzed 14 principal component carries out correlation analysis with sea surface temperature that is delay time from 0month until 11month. Correlation analysis carries out sea surface temperatures and calculated cycle component of the low frequency through Wavelet Transform analysis form principal component. Result of correlation analysis, yang(+) correlation is bigger than yin(-) correlation. It is possible to check similar correlation statistically the area of sea surface temperature with sea surface temperature in the Pacific. Forecasting possibility of the future drought make propose using sea surface temperature.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.2
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• pp.94-102
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• 1998

Temporal changes, density, calcimass, mode of occurrence, size-frequency histogram and survivorship curves were studied for the molluscan death assemblages on a macrotidal flat, Inchon, Korea. The living and death assemblages were compared on the basis of the taxonomic compositions and their numerical abundances. A total of 28 species (16 taxa in gastropods and 12 in bivalves) were identified. Most of the dead shells were the species inhabiting that intertidal mud flat. Species diversity was higher in gastropods than in bivalves. Seasonal variation of the calcimass was influenced by the mactrid bivalve, Mactra veneriformis. Shell-boring naticid gastropods preferred selecting the umbo areas of various valves. Size-frequency distribution and size-specific survivorship curves were analyzed for the dominant species. Survivorship curve of the tellinid bivalve, Morella rutila was convex-up in shape, which is congruent with the expected equilibrium condition but indicates higher mortality in winter. Whereas the survivorship curves of Mactra veneriformis and Reticunassa festiva were semi convex-up with dual modes, suggesting a disequilibrium due to the changes in recruitment and seasonal mortality. This study suggests that the dead shell assemblages may be useful in getting population information like live molluscan assemblages, if solved for several problems related to taphonomic processes.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.39.1-39
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• 1981

The author presents clinical study for 111 cases of tinnitus with pure tone audiometry from Jan. 1, 1978 to Dec. 31, 1980 in department of otolaryngology, Ewha Womans University Hospital. The results were as follows; 1) Male to Female ratio was as 1 : 1, and peak age incidence was in the age group of 21 to 30. 2) Most frequent duration was 1 month to 1 year in the cases of the tinnitus. 3) The patient who complained tinnitus only was 10.0% and the patient who complained tinnitus with hearing impairment was 72.0% in the cases of tinnitus. 4) The affected site in the tinnitus, in order of frequency were; Both ear 38.7% Left ear 32.4% Right ear 28.9% 5) The drum finding, in order frequency were; Normal 48.0% Retraction 33.1% Perforation 8.4% 6) The degree of hearing loss in the audiometry were; Normal 29.2% Moderate severe 22.7% 7) The shape of hearing impairments were; High tone loss 46.9% Flat 33.0% Low tone loss 11.9% 8) The occurrence of $C_{5}$ dip was 11.0% in cases of the tinnitus. 9) The classification of hearing loss were; Sensorineural hearing loss 46.9% Mixed hearing loss 33.1 % Conductive hearing loss 20.1%

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3518-3524
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• 2015

Spatial and time variation of the precipitation in Korea is high, therefore, more than 2/3 of the annual precipitation is concentrated during the rainy season. Climate change also causes the intensive rainfall in the area of dense population, thus the occurrence frequency of the heavy flood in the impervious area has been increased. Therefore, the structural food mitigation measures such as the construction of the higher design frequency stormwater pipes, pumping stations, and/or detention ponds. The flood bypass tunnel or retention storage is also one of the efficient structures to mitigate flood damage in the urban area. However, the economic feasibility has been controversial because the flood bypass tunnel might be used once or twice a year. To solve the problem, the multi-functional tunnel for the urban traffic and flooding bypass has been considered. In this study, the design criteria of the road and water tunnel has been analysed and the composite design criteria is proposed for the multi-functional tunnel which is expected to be constructed.

• Tunnel and Underground Space
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• v.34 no.2
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• pp.169-184
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• 2024

This study investigates acoustic emission (AE) and micro-deformation characteristics of circular openings through biaxial compression experiments. The experimental results showed a significant increase in the frequency, count, energy, and amplitude of AE signals immediately before damage occurred in the circular opening. The differences in frequency and count between before and after damage initiation were significantly pronounced, indicating suitable factors for identifying damage occurrence in circular openings. The results for digital image correlation (DIC) technique revealed that micro-deformation was concentrated around the openings, as evidenced by the spatial distribution of strain. In addition, spalling was observed at the end of the experiments. The AE and micro-deformation characteristics presented in this study are expected to serve as fundamental data for evaluating the stability of underground openings and boreholes for deep subsurface projects.

• Journal of Intelligence and Information Systems
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• v.22 no.2
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• pp.115-125
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• 2016

The Bollinger Band indicating the current price position in the recent price action range is obtained by adding/substracting the simple standard deviation (SSD) to/from the simple moving average (SMA). In this paper, we first compare the characteristics of the SMA and the exponential moving average (EMA) in the operator's point of view. A basic equation is obtained between the interval length N of the SMA operator and the weighting factor ${\rho}$ of the EMA operator, that makes the centers of the 1st order momentums of each operator impulse respoinse identical. For equivalent N and ${\rho}$, frequency response examples are obtained and compared by using the discrete time Fourier transform. Based on observation that the SMA operator reacts more excessively than the EMA operator, we propose a novel exponential standard deviation (ESD) band centered at the EMA and derive an auto recursive formula for the proposed ESD band. Practical examples for the ESD band show that it has a smoother bound on the price action range than the Bollinger Band. Comparisons are also made for the gap corrected chart to show the advantageous feature of the ESD band even in the case of gap occurrence. Trading techniques developed for the Bollinger Band can be straight forwardly applied to those for the ESD band.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.41-48
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• 2022

This study tried to empirically explore which issues related to the social service agency for public(as below SSA), that is, social perceptions were formed, by using mess media related to the SSA. This study is meaningful in that it identifies the overall social perception and trend of SSA through public opinion. In order to extract media trend data, the search used the big data analysis system, Textom, to collect data from the representative portals Naver News and Daum News. The collected texts were 1,299 in 2020 and 1,410 in 2021, for a total of 2,709. As a result of the analysis, first, the most derived words in relation to the frequency of text appearance were 'SSA', 'establishment', and 'operation'. Second, as a result of the N-gram analysis, the pairs of words directly related to the SSA 'SSA and public', 'SSA and opening', 'SSA and launch', and 'SSA and Department Director', 'SSA and Staff', 'SSA and Caregiver' etc. Third, in the results of TF-IDF analysis and word network analysis, similar to the word occurrence frequency and N-gram results, 'establishment', 'operation', 'public', 'launch', 'provided', 'opened', ' 'Holding' and 'Care' were derived. Based on the above analysis results, it was suggested to strengthen the emergency care support group, to commercialize it in detail, and to stabilize jobs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.23-33
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• 2009

Climate change, abnormal weather, and unprecedented extreme weather events have appeared globally. Interest in their size, frequency, and changes in spatial distribution has been heightened. However, the events do not display regional or regular patterns or cycles. Therefore, it is difficult to carry out quantified evaluation of their frequency and tendency. For more objective evaluation of extreme weather events, this study proposed a rainfall extreme weather index (STARDEX, 2005). To compare the present and future spatio-temporal distribution of extreme weather events, each index was calculated from the past data collected from 66 observation points nationwide operated by Korea Meteorological Administration (KMA). Tendencies up to now have been analyzed. Then, using SRES B2 scenario and 2045s (2031-2050) data from YONU CGCM simulation were used to compute differences among each of future extreme weather event indices and their tendencies were spatially expressed.The results shows increased rainfall tendency in the East-West inland direction during the summer. In autumn, rainfall tendency increased in some parts of Gangwon-do and the south coast. In the meanwhile, the analysis of the duration of prolonged dry period, which can be contrasted with the occurrence of rainfall or its concentration, showed that the dryness tendency was more pronounced in autumn rather than summer. Geographically, the tendency was more remarkable in Jeju-do and areas near coastal areas.

• Journal of Korea Water Resources Association
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• v.39 no.4 s.165
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• pp.373-382
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• 2006

In this study a theoretical drought severity-duration-frequency analysis is performed based on a simple Rectangular Pulses Poisson Process Model(RPPM). Data set with various durations are prepared for a given truncation level, whose statistics are then derived to be used for parameter estimation. These parameters are then used for the theoretical drought severity-duration-frequency analysis. The analysis is considered for two cases; one is to consider the overlap probability and the other is not. The drought severity of considering the overlap probability increases more as the return period increases. However, the overlap probability itself decreases as the duration increases, which is because the occurrence probability of events decreases as the duration increases. Also, if the duration increases, the events rarely or even not occur, since parameters of the model cannot be estimated in those cases, so the drought severity may not be computed. This is an obvious limitation of the simple RPPM. In this study the return periods of the important drought events occurred in Seoul are estimated using the results of the study. If the return period of an event is assumed to be the longest one among those with various durations, the return periods of some important event in Seoul are estimated to be between 14 and 35 years. These return periods are not so long to indicate that these droughts can occur frequently.