• Title/Summary/Keyword: Spatio-temporal Data

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Spawning Density and Recruitment of Janpanese Anchovy, Engraulis japonica in the Southern Sea of Korea in 2007 (2007년 남해안 멸치의 산란밀도와 어장가입)

  • CHA, Byung Yul;Yang, Won Seok;Kim, Joo Il;Jang, Sun Ik;Chu, Eun Kyeong;Park, Ju Sam
    • Korean Journal of Ichthyology
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    • v.20 no.3
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    • pp.190-197
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    • 2008
  • Spatio-temporal distribution of eggs and larvae of Japanese anchovy Engraulis japonica in the southern sea of Korea was determined using data obtained from icthyoplanktonic surveys and oceanographic observations between Goheung Peninsula and Goeje Island from May to August 2007. Commercial anchovy catch and size composition from four local fishery cooperative associations were also analyzed in relation to the geographic distribution of eggs and larvae. The abundance of anchovy eggs increased from May to July and was lowest in August. Eggs were mainly distributed between Namhae Island and Goeje Island, where water temperatures were $15{\sim}24^{\circ}C$ and salinities were 32~35‰. In 2007 anchovy landings between Namhae Island and Goeje Island were 11,409 tons at Tongyeong association, 4,137 tons at Masan association, and 2,487 tons at Sacheon association. However, landings between Goheung and Yeosu Peninsula were only 4,411 tons (at Yeosu association). The catch by anchovy tow net was high in the area where eggs were abundantly distributed. This indicates that the distribution of egg density was directly correlated with recruitment of E. japonica. All growth stages were abundant in the study area, indicating that this area is a major spawning and growing ground of E. japonica in Korean waters.

Study on Geostatistical Method for an Effectiveness Analysis on Carbon Reduction Policy - Focusing on the Carbon Point System (탄소저감정책 효과분석을 위한 공간통계기법 적용방안 연구 - 탄소포인트제도를 대상으로 -)

  • Hwang, Hae-Seong;Joo, Yong-Jin;Koh, June-Hwan
    • Spatial Information Research
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    • v.20 no.1
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    • pp.71-80
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    • 2012
  • Carbon Point system is Climate Change Action Program by providing incentives in proportion to voluntary reduction of energy consumption such as electricity, gas and water for houses, commercial facilities. So far, existing researches have been limited to construction of GHG(Green House Gas) Inventory and have little attention to empirical impact analysis on carbon reduction policy regarding the residential section. Therefore, this paper is intended to provide convincing findings of impact analysis on carbon reduction, revolving around the carbon point system. For this, we firstly calculated the carbon emission by using electricity and gas usage data in household targeting to Seongbuk-Gu. Carrying out IPA and spatio-temporal analysis. Then, we are capable of visualizing spatial patterns from 2007 to 2009 as a macro analysis. Following that, we explored the effect on carbon point system through Ex ante-Ex post Analysis by paired t-test. To conclude, we can spatially identify the distribution with a significant difference between carbon emissions according to energy use as a micro analysis by Hot Spot to Analysis on point entities. It is to be hoped that this method will be utilized to establish various policies and to evaluate the effect of reduction of GHG.

The Evaluation of TOPLATS Land Surface Model Application for Forecasting Flash Flood in mountainous areas (산지돌발홍수 예측을 위한 TOPLATS 지표해석모델 적용성 평가)

  • Lee, Byong Jua;Choi, Su Mina;Yoon, Seong Sima;Choi, Young Jean
    • Journal of Korea Water Resources Association
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    • v.49 no.1
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    • pp.19-28
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    • 2016
  • The objective of this study is the generation of the gridded flash flood index using the gridded hydrologic components of TOPLATS land surface model and statistic flash flood index model. The accuracy of this method is also examined in this study. The study area is the national capital region of Korea, and 38 flash flood damages had occurred from 2009 to 2012. The spatio-temporal resolutions of land surface model are 1 h and 1 km, respectively. The gridded meteorological data are generated using the inverse distance weight method with automatic weather stations (AWSs) of Korea Meteorological Administration (KMA). The hydrological components (e.g., surface runoff, soil water contents, and water table depth) of cells corresponding to the positions of 38 flood damages reasonably respond to the cell based hourly rainfalls. Under the total rainfall condition, the gridded flash flood index shows 71% to 87% from 4 h to 6 h in the lead time based on the rescue request time and 42% to 52% of accuracy at 0 h which means that the time period of the lead time is in a limited rescue request time. From these results, it is known that the gridded flash flood index using the cell based hydrological components from land surface model and the statistic flash flood index model have a capability to predict flash flood in the mountainous area.

An Evaluation of Human Sensibility on Perceived Texture for Real Haptic Representation (사실적인 햅틱 표현을 위한 질감지각 감성 평가)

  • Kim, Seung-Chan;Kyung, Ki-Uk;Sohn, Jin-Hun;Kwon, Dong-Soo
    • Journal of KIISE:Software and Applications
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    • v.34 no.10
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    • pp.900-909
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    • 2007
  • This paper describes an experiment on the evaluation of human sensibility by monitoring responses to changes In the frequency and amplitude of a tactile display system. Preliminary tasks were performed to obtain effective adjectives concerning texture perception. The number of collected adjectives was originally 33. This number of adjectives was reduced to 14 by a suitability survey that asked whether an adjective is suitable for expressing a texture feeling. Finally after performing a semantic similarity evaluation, the number of adjectives was further reduced to ten and these ten were used in the main experiment. In the main experiment, selected sandpaper types and 15 selected combinations of frequencies and amplitudes of a tactile display were utilized to quantitatively evaluate the ten adjectives using a bipolar seven-point scale. The data show that a relationship exists between the independent variables(frequency, amplitude, and grit site) and the dependent variable(perceived texture). That is, the change of frequency and amplitude is directly related to perceived roughness or essential elements of human tactile sensitivity found in the preliminary experiment.

Effects of morbidity in Korean peninsula due to sand dust using satellite aerosol observations (위성기상자료를 활용한 황사에 따른 한반도 국민 건강영향평가)

  • Choi, Minyoung;Kim, Hyunglok;Kim, Sangman;Choi, Minha
    • Korean Journal of Remote Sensing
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    • v.32 no.5
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    • pp.499-509
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    • 2016
  • The occurrence of sand dust has been steadily increased since 1990 and the amount of damage was also increased. In most of previous studies, ground based observations were used for sand dust analyses, but its high spatio-temporal variability has not been well understood. In this study, satellite aerosol observations were used to overcome current limitations of the sand dust variability in space and time and to estimate associations with morbidity of respiratory and cardiovascular ailments. In general, high AODs were observed in the west part of the Koran peninsula in spring. The reasonable associations between the morbidity and sand dust were observed from April to July with highest positive correlation (~0.6) at three month lags (lag 3). Based on the results, we found a utility of the satellite aerosol observations for sand dust analyses by considering of morbidity effects. In addition, health effect against the sand dust is proved to be examined and smooth medical supplies and prevention of undesired medical expenses would be possible.

Characteristics of Long-term Variability of the Net Heat Flux on the Sea Surface in the East Asian Marginal Seas (동아시아 해역 해수면 순열속의 장기 변동 특성)

  • Lee, Seong-Wook;Na, Jung-Yul
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.2
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    • pp.86-94
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    • 2000
  • In order to extract the spatio-temporal characteristics of long-term variability of the net heat flux on the sea surface in the East Asian marginal seas, empirical orthogonal function (EOF) analysis was conducted using data set calculated every 12 hours interval during 1978-1995. Among the first three modes explaining 73% of the total variance, the first mode having high peak at 1 year period indicates high variability area around the Sandong Peninsula and central and northeastern part of the East Sea. In the second mode which has spatial distribution of dipole type at the north and south, the peaks appear at 3.6 year and 2.3 year cycles. Time coefficient of the second EOF is believed to have close relation with the E1 Nino and has out-of-phase variation with NINO3 SST. Lagged correlation between NINO3 SST and time coefficient of the second EOF indicates four month time delay in the NINO3 SST. In the third mode which has opposite sign at the east and west, the periodicity of 6-9 year cycle has relatively clear appearance compared to other two EOFs. Also, high heat loss exceeding 800 W/$m^{2}$ in winter time occured at the south part of the Sandong Peninsula and Vladivostok. It reveals more frequent occurrence of about two times at the Sandong Peninsula than Vladivostok. The event is concentrated in January at Vladivostok, but it occurs primarily in December and January at the Sandong Peninsula.

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Spatio-temporal Moth Diversity (Insecta: Lepidoptera) of Mt. Baegun-san, Gwangyang, Jeonnam (전라남도 광양시 백운산 나방 (곤충강: 나비목)의 시공간적 다양성 연구)

  • Choi, Sei-Woong;Nho, Dong-Ho;Kim, Sang-Soo;Hong, Kee-Jeong
    • Korean Journal of Ecology and Environment
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    • v.49 no.1
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    • pp.62-66
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    • 2016
  • This study was aimed to investigate the elevational and seasonal variation of moth diversity of Mt. Baegun-san, Gwangyang-city, Jeonnam. Moth collecting was carried out using a UV light trap at three different elevational sites from September to October 2014 and from April to October 2015 (9 times) except winter. A total of 288 moth species and 1,444 individuals in 15 families were identified. Geometridae (97 species and 740 individuals) were the most dominant in the numbers of species and individuals, followed by Noctuidae (62 species, 193 individuals), Erebidae (52 species, 177 individuals) and Notodontidae (16 species, 111 individuals). Elevational change showed that the lower elevation, the higher number of species and individuals. Seasonal change of numbers of species and individuals showed the M-shaped pattern with June and August peaks. Compared to the previous records from historical literatures, 197 species were newly added and the total moth species richness of Mt. Baegun-san comprised 449 species in 20 families. The Chao 2 estimated number of species using the observed species including unpublished data set was 1,530 species that comprised about 43% of the Korean Lepidopteran fauna. This large number of estimated species requested the more extensive and long-term survey for better understanding of the total moth fauna in this area.

Verifying the Voluntariness of the Location of Drunk Driving Accidents (음주운전사고 발생위치의 임의성 검증)

  • Nam, Kwang-Woo;Kang, In-Joo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.2
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    • pp.129-138
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    • 2007
  • The cases of drunk driving accidents have been steadily increasing every year. The number of accidents was quadrupled from 7,303 cases in 1990 to 25,150 cases in 2004. In addition, the proportion of drunk driving accidents to total traffic accidents was 2.9% in 1990 but it increased to 13.0% in 2003. Studies of drunk driving accidents have been focusing on analyzing psychological decisive factors, classifying drivers' individual characters and types of drunk driving accidents by considering the location of drunk driving accidents. This study assumed that drunk driving accidents would have regular characteristics in respect to spatiality and analyzed its relation with spatial factors such as, accident black spot, the location of bars, the distance of drivers' houses, and spatio-temporal distributional characteristics through drawing density distribution and connecting the time of accidents. In order to achieve the goal of this study, the individual location information was organized and drawn as types of GIS data. From the result of density distribution using Kernel Density Mapping and analysis through the coefficient of areal correspondence, it was understood that drunk driving accidents correlates with some spatial factors.

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User-Centered Climate Change Scenarios Technique Development and Application of Korean Peninsula (사용자 중심의 기후변화 시나리오 상세화 기법 개발 및 한반도 적용)

  • Cho, Jaepil;Jung, Imgook;Cho, Wonil;Hwang, Syewoon
    • Journal of Climate Change Research
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    • v.9 no.1
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    • pp.13-29
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    • 2018
  • This study presented evaluation procedure for selecting appropriate GCMs and downscaling method by focusing on the climate extreme indices suitable for climate change adaptation. The procedure includes six stages of processes as follows: 1) exclusion of unsuitable GCM through raw GCM analysis before bias correction; 2) calculation of the climate extreme indices and selection of downscaling method by evaluating reproducibility for the past and distortion rate for the future period; 3) selection of downscaling method based on evaluation of reproducibility of spatial correlation among weather stations; and 4) MME calculation using weight factors and evaluation of uncertainty range depending on number of GCMs. The presented procedure was applied to 60 weather stations where there are observed data for the past 30 year period on Korea Peninsula. First, 22 GCMs were selected through the evaluation of the spatio-temporal reproducibility of 29 GCMs. Between Simple Quantile Mapping (SQM) and Spatial Disaggregation Quantile Delta Mapping (SDQDM) methods, SQM was selected based on the reproducibility of 27 climate extreme indices for the past and reproducibility evaluation of spatial correlation in precipitation and temperature. Total precipitation (prcptot) and annual 1-day maximum precipitation (rx1day), which is respectively related to water supply and floods, were selected and MME-based future projections were estimated for near-future (2010-2039), the mid-future (2040-2069), and the far-future (2070-2099) based on the weight factors by GCM. The prcptot and rx1day increased as time goes farther from the near-future to the far-future and RCP 8.5 showed a higher rate of increase in both indices compared to RCP 4.5 scenario. It was also found that use of 20 GCM out of 22 explains 80% of the overall variation in all combinations of RCP scenarios and future periods. The result of this study is an example of an application in Korea Peninsula and APCC Integrated Modeling Solution (AIMS) can be utilized in various areas and fields if users want to apply the proposed procedure directly to a target area.

Comparison of CH4 Emission by Open-path and Closed Chamber Methods in the Paddy Rice Fields (벼논에서 open-path와 closed chamber 방법 간 메탄 배출량 비교)

  • Jeong, Hyun-cheol;Choi, Eun-jung;Kim, Gun-yeob;Lee, Sun-il;Lee, Jong-sik
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.507-516
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    • 2018
  • The closed chamber method, which is one of the most commonly used method for measuring greenhouse gases produced in rice paddy fields, has limitations in measuring dynamic $CH_4$ flux with spatio-temporal constrains. In order to deal with the limitation of the closed chamber method, some studies based on open-path of eddy covariance method have been actively conducted recently. The aim of this study was to compare the $CH_4$ fluxes measured by open-path and closed chamber method in the paddy rice fields. The open-path, one of the gas ($CO_2$, $CH_4$ etc.) analysis methods, is technology where a laser beam is emitted from the source passes through the open cell, reflecting multiple times from the two mirrors, and then detecting. The $CH_4$ emission patterns by these two methods during rice cultivation season were similar, but the total $CH_4$ emission measured by open-path method were 31% less than of the amount measured by closed chamber. The reason for the difference in $CH_4$ emission was due to overestimation by closed chamber and underestimation by open-path. The closed chamber method can overestimate $CH_4$ emissions due to environmental changes caused by high temperature and light interruption by acrylic partition in chamber. On the other hand, the open-path method for eddy covariance can underestimate its emission because it assumes density fluctuations and horizontal homogeneous terrain negligible However, comparing $CH_4$ fluxes at the same sampling time (AM 10:30-11:00, 30-min fluxes) showed good agreements ($r^2=0.9064$). The open-path measurement technique is expected to be a good way to compensate for the disadvantage of the closed chamber method because it can monitor dynamic $CH_4$ fluctuation even if data loss is taken into account.