• Title/Summary/Keyword: region division method

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Temporal and Spatial Variations of Primary Productivity in Estuary of Youngsan River and Mokpo Coastal Areas (영산강 하구역 및 목포 연안 해역 식물플랑크톤 1차생산력의 시.공간적 변화)

  • Lee, Yeon-Jung;Min, Jun-Oh;Shin, Yong-Sik;Kim, Sung-Hwan;Shin, Kyung-Hoon
    • Korean Journal of Ecology and Environment
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    • v.44 no.4
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    • pp.327-336
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    • 2011
  • Temporal and spatial variations of primary productivity were investigated in the estuary of Youngsan River and Mokpo coastal areas in 2009. After heavy rain, concentrations of ammonium, phosphate, and silicate increased at six stations in August. The torrential rainfall may cause an increase in nutrient concentrations during summer. There is no limitation of nutrients (except for February at the mid-Youngsan estuarine region YS2) but a potential phosphate limitation was apparent at all stations. Silicate depletion was observed at YS2 in February due to a massive diatom bloom. The trophic status of the Youngsan estuary and Mokpo coastal areas were inferred from an assessment of the primary productivity. In February and May, YS1 (upper Youngsan estuary site) and YS2, YS3 (near the Youngsan river estuary barrage), MP1 (upper Mokpo coastal region site) were appropriately assigned to the mesotrophic category. MP2 (mid-Mokpo coastal region site) and MP3 (outer site of Mokpo coastal region) were assigned to the oligotrophic category. All stations were classified to the oligotrophic status in November. In August, after heavy rain, Youngsan estuary stations maintained mesotrophic status. On the other hand, MP1 and MP2 were classified in the eutrophic category and MP3 to mesotrophic status. In particular, primary productivities of MP1 and MP2 were 9 and 7 times higher respectively than the standard of eutrophic status ($1,000-mgC\;m^{-2}d^{-1}$). These results suggest that a massive freshwater discharge from the Youngsan River estuary should be considered a main factor in the occurrence of phytoplankton bloom in Mokpo coastal areas during summer. Seasonal variations of primary productivity are closely related with depth-integrated Chl. a.

A Study on Flood Storage Plans of Farmlands for Extreme Flood Reduction (극한홍수 저감을 위한 농경지의 저류지화 방안 연구)

  • Kang, Hyeong-Sik;Cho, Seong-Yun;Song, Young-Il
    • Journal of Korea Water Resources Association
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    • v.44 no.10
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    • pp.787-795
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    • 2011
  • Extreme water events such as heavy rainfalls due to recent climate change are continually increasing and their scale has also shown an increasing trend. To overcome these natural disasters, this policy study suggests securing lateral river space as an effective method for extreme flood. To support the importance of restoration and expansion of lateral river space, Gumi upstream region of the Nakdong River basin was chosen as a target area and flood reduction analysis of the washland by using LISFLOOD model have been examined. The 500-year frequency flood was simulated for the estimation of possibly occurable flood level and it turns out that the secured lateral river space on the selected site effectively lowers about 0.53 m flood level and reduces the flood damage of the city on the lower reaches of the river. In addition, based on this result, multilateral river space securing plans were compared, and conservation easement and natural disaster insurance were suggested for sustainable and cost-effective alternatives. The costs of land purchase and conservation easement for securing the river space were also compared.

Assessing Disaster Response Capability and Feature Analysis for Coastal Residents of Korea using Sampling Process (표본추출법을 이용한 연안주민의 재해대응능력 평가 및 특성 분석)

  • Kang, Tae-Soon;Oh, Hyeong-Min;Kim, Jong-Kyu;Jeong, Kwang-Young;Hwang, Soon-mi;Kim, Soo-Min
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.20 no.1
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    • pp.55-61
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    • 2017
  • This study conducted a survey to evaluate the disaster response capability of coastal residents and analyzed the characteristics. For the sampling process, nonrandom sampling method was used. Sample size is 4,520 and sample error is ${\pm}1.5%p$ at 95% confidence level. As a result of the survey, 72% and 68% of the respondents said that they recognized the emergency contact network and listened to the disaster broadcast. On the other hand, 17% and 18% said that they organized the local voluntary disaster prevention teams and participated in disaster preparedness training. In addition, male's disaster response capability was higher than female's, and first aid techniques and participation in disaster preparedness training were higher in teens and twenties. By occupation, public official possess the highest response capability. By region, it was high in the East coast and low in the South coast. It is necessary that the authorities improve the national disaster preparedness training and publicity to enhance the coastal disaster response capability of coastal residents.

Fine Co-registration Performance of KOMPSAT-3·3A Imagery According to Convergence Angles (수렴각에 따른 KOMPSAT-3·3A호 영상 간 정밀 상호좌표등록 결과 분석)

  • Han, Youkyung;Kim, Taeheon;Kim, Yeji;Lee, Jeongho
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.6
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    • pp.491-498
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    • 2019
  • This study analyzed how the accuracy of co-registration varies depending on the convergence angles between two KOMPSAT-3·3A images. Most very-high-resolution satellite images provide initial coordinate information through metadata. Since the search area for performing image co-registration can be reduced by using the initial coordinate information, in this study, the mutual information method showing high matching reliability in the small search area is used. Initial coarse co-registration was performed by using multi-spectral images with relatively low resolution, and precise fine co-registration was conducted centering on the region of interest of the panchromatic image for more accurate co-registration performance. The experiment was conducted by 120 combination of 16 KOMPSAT-3·3A 1G images taken in Daejeon area. Experimental results show that a correlation coefficient between the convergence angles and fine co-registration errors was 0.59. In particular, we have shown the larger the convergence angle, the lower the accuracy of co-registration performance.

A Feasibility Study on the Application of TVDI on Accessing Wildfire Danger in the Korean Peninsula (한반도 지역 산불 발생 위험도 예측에 TVDI 적용 가능성 고찰)

  • Kim, Kwang Nyun;Kim, Seung Hee;Won, Myoung Soo;Jang, Keun Chang;Choi, Won Jun;Lee, Yun Gon
    • Korean Journal of Remote Sensing
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    • v.35 no.6_3
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    • pp.1197-1208
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    • 2019
  • Wildfire is a major natural disaster affecting socioeconomics and ecology. Remote sensing data have been widely used to estimate the wildfire danger with an advantage of higher spatial resolution. Among the several wildfire related indices using remote sensing data, Temperature Vegetation Dryness Index (TVDI) assesses wildfire danger based on both Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST). Although TVDI has physical advantages by considering both weather and vegetation condition, previous studies have shown TVDI does not performed well compare to other wildfire related indices over the Korean Peninsula. In this study we have attempted multiple modification to improve TVDI performance over the study region. In-situ measured air temperature was employed to increase accuracy, regression line was generated using monthly data to include seasonal effect, and TVDI was calculated at each province level to consider vegetation type and local climate. The modified TVDI calculation method was evaluated in wildfire cases and showed significant improvement in wildfire danger estimation.

Non-CpG Methylation of Pre-1 Sequence in Pig SCNT Blastocysts (돼지 체세포복제 배반포에서 Pre-1 영역의 Non-CpG 메틸화 양상)

  • Ko, Yeoung-Gyu;Im, Gi-Sun;Lee, Hwi-Cheul;Cho, Sang-Rae;Choi, Sun-Ho;Choe, Chang-Yong;Lee, Poong-Yeon;Cho, Chang-Yeon;Cho, Jae-Hyeon;Yoo, Young-Hee
    • Reproductive and Developmental Biology
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    • v.35 no.1
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    • pp.93-97
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    • 2011
  • Previously, we reported that the osmolarity conditions in the satellite region were affected CpG DNA methylation status while Pre-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. This study was conducted to investigate the DNA methylation status of repeat sequences in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05 M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. The DNA methylation status of the Pre-1 sequences in blastocysts was characterized using a bisulfite-sequencing method. Intriguingly, in the present study, we found the unique DNA methylation at several non-CpG sequences at the Pre-1 sequences in all groups. The non-CpG methylation was hypermethylated in all three groups, including in vivo group (86.90% of PZM-3; 83.87% of NaCl; 84.82% of sucrose; 90.94% of in vivo embryos). To determine whether certain non-CpG methylated sites were preferentially methylated, we also investigated the methylation degree of CpA, CpT and CpC. Excepting in vivo group, preference of methylation was CpT>CpC>CpA in all three groups investigated. These results indicate that DNA methylation of Pre-1 sequences was hypermethylated in CpG as well as non-CpG site, regardless modification of osmolarity in a culture media.

Breast Cancer Clustering in Kanagawa, Japan: A Geographic Analysis

  • Katayama, Kayoko;Yokoyama, Kazuhito;Yako-Suketomo, Hiroko;Okamoto, Naoyuki;Tango, Toshiro;Inaba, Yutaka
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.455-460
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    • 2014
  • Background: The purpose of the present study was to determine geographic clustering of breast cancer incidence in Kanagawa Prefecture, using cancer registry data. The study also aimed at examining the association between socio-economic factors and any identified cluster. Materials and Methods: Incidence data were collected for women who were first diagnosed with breast cancer during the period from January to December 2006 in Kanagawa. The data consisted of 2,326 incidence cases extracted from the total of 34,323 Kanagawa Cancer Registration data issued in 2011. To adjust for differences in age distribution, the standardized mortality ratio (SMR) and the standardized incidence ratio (SIR) of breast cancer were calculated for each of 56 municipalities (e.g., city, special ward, town, and village) in Kanagawa by an indirect method using Kanagawa female population data. Spatial scan statistics were used to detect any area of elevated risk as a cluster for breast cancer deaths and/or incidences. The Student t-test was performed to examine differences in socio-economic variables, viz, persons per household, total fertility rate, age at first marriage for women, and marriage rate, between cluster and other regions. Results: There was a statistically significant cluster of breast cancer incidence (p=0.001) composed of 11 municipalities in southeastern area of Kanagawa Prefecture, whose SIR was 35 percent higher than that of the remainder of Kanagawa Prefecture. In this cluster, average value of age at first-marriage for women was significantly higher than in the rest of Kanagawa (p=0.017). No statistically significant clusters of breast cancer deaths were detected (p=0.53). Conclusions: There was a statistically significant cluster of high breast cancer incidence in southeastern area of Kanagawa Prefecture. It was suggested that the cluster region was related to the tendency to marry later. This study methodology will be helpful in the analysis of geographical disparities in cancer deaths and incidence.

Study on the Effect of Accessibility of Child Care Services on User Satisfaction -Comparison between Dual-earner and Single-earner Familes (보육서비스 접근성이 이용자 만족도에 미치는 영향 연구 - 맞벌이 여부에 따른 차이 비교)

  • Kim, Yu-Ri;Cho, Ja-Young
    • Journal of the Korea Convergence Society
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    • v.11 no.7
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    • pp.281-287
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    • 2020
  • The purpose of this study is to examine whether the effect of service satisfaction regarding the accessibility of child care services varies between dual-earner and single-earner families. In particular, we conducted the analysis by dividing the service accessibility into sub-areas. The study sample consisted of 267 parents living in Seoul and Gyeonggi region. As a result of the analysis, accommodation in use time and affordability influenced satisfaction in the single-earner families, and information acquisition and acceptability in the dual-earner families. For single-earner families, the more convenient the use time of the childcare institution and the less the service cost burden, the higher the satisfaction. The dual-earner families had higher satisfaction levels if it was easier to obtain information about the childcare centers and weaker the religious characteristics of the childcare centers. Based on the research results, it is necessary to differentiate the burden of cost and provide more flexible operation of childcare service operating hours. In addition, it is necessary to devise a policy method to increase the transparency of information to childcare institutions.

Isolation and Characterization of Microsatellites in the Brown Planthopper, Nilaparvata lugens $St{\aa}l$ (벼멸구(Nilaparvata lugens)에서 마이크로새털라이트 마커의 분리 및 특성검정)

  • Mun Jeomhee;Song Yoo Han;Roderick George K.
    • Korean journal of applied entomology
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    • v.43 no.4 s.137
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    • pp.311-315
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    • 2004
  • The brown planthopper, Nilaparvata lugens, is among the most serious insect pests of rice. It is widely distributed in Asia, Australia and Pacific islands. An earlier mitochondrial DNA study revealed that there exist significant genetic differences between populations north and south of the Red River Delta region in Vietnam. However the mitochondrial DNA was not sufficiently variable to examine the sources of immigration. For a more detailed analysis of geographic population structure of N. lugens, we developed microsatellite markers. Thirty-seven putative microsatellite loci were isolated using a magnetic biotin method, and five primer pairs designed from the flanking regions of sequenced microsatellite clones were labeled with fluorescent. Of these five primer sets, two have proven to be useful across all the samples we used in this study. We used variation at these two microsatellite loci to test the hypothesis that N. lugens biotypes (1, 2, and 3) sampled from laboratory selection constituted distinct genetic units. Allele frequency differences among the three major biotype categories were not significantly different at one locus (27035). However, the other (7314) did show differences among the major three biotypes. The methods we describe here will be useful for studying population structure of crop pest and for tracking the patterns of migratory pest like the rice planthoppers.

Analytical and Experimental Study on the Quality Stability of Multi Roll Forming Process (멀티 롤 포밍 공정의 품질 안정성에 대한 해석 및 실험적 연구)

  • Son, Jae-Hwan;Han, Chang-Woo;Ryu, Kyung-Jin;Kang, Hae-Dong;Kim, Chul-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6977-6984
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    • 2015
  • It is faced with the necessity of multi roll forming process of the ball slide rail which is made by adding the separate manufacturing processes, piercing, bending, trimming, to the roll forming process of a continuous plastic deformation, to improve the quality. However, the vibration and noise of the press machine in this process leads to the quality degradation of slide rail manufactured in this process. In this study, the roll was designed considering the optimal strain rates by the roll forming program with finite element method. And to estimate the static stability of the multi process the Von-Mises stress and deformation on the press was calculated with a structural analysis program. Also, to avoid driving systems in the resonance region their natural frequencies in the 1st and 2nd mode were calculated through the modal analysis. To verify its dynamic stability improvement the magnitudes of noise and vibration in the existing and studied system were compared using a microphone and accelerometers. And the widths and surface roughnesses of the rails which had been produced in the existing and studied process were measured. Therefore, it is known that multi roll forming process is stable in the analytical and experimental study.