• Title/Summary/Keyword: Z-R Relationship

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Rainfall Intensity Estimation Using Geostationary Satellite Data Based on Machine Learning: A Case Study in the Korean Peninsula in Summer (정지 궤도 기상 위성을 이용한 기계 학습 기반 강우 강도 추정: 한반도 여름철을 대상으로)

  • Shin, Yeji;Han, Daehyeon;Im, Jungho
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1405-1423
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    • 2021
  • Precipitation is one of the main factors that affect water and energy cycles, and its estimation plays a very important role in securing water resources and timely responding to water disasters. Satellite-based quantitative precipitation estimation (QPE) has the advantage of covering large areas at high spatiotemporal resolution. In this study, machine learning-based rainfall intensity models were developed using Himawari-8 Advanced Himawari Imager (AHI) water vapor channel (6.7 ㎛), infrared channel (10.8 ㎛), and weather radar Column Max (CMAX) composite data based on random forest (RF). The target variables were weather radar reflectivity (dBZ) and rainfall intensity (mm/hr) converted by the Z-R relationship. The results showed that the model which learned CMAX reflectivity produced the Critical Success Index (CSI) of 0.34 and the Mean-Absolute-Error (MAE) of 4.82 mm/hr. When compared to the GeoKompsat-2 and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN)-Cloud Classification System (CCS) rainfall intensity products, the accuracies improved by 21.73% and 10.81% for CSI, and 31.33% and 23.49% for MAE, respectively. The spatial distribution of the estimated rainfall intensity was much more similar to the radar data than the existing products.

Mediating Effects of Resilience on the Relation between Emotional Intelligence and Self-Efficacy on Career Decision-Making in Nursing Students (간호대학생의 감성지수가 진로결정자기효능감에 미치는 영향: 회복탄력성의 매개효과 중심으로)

  • Lim, Hyun-Suk;Ryu, Jeong-Lim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.151-160
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    • 2020
  • The purpose of this study was to investigate the moderating mediation effect of resilience, on the relationship between emotional intelligence and self-efficacy in career decision-making of nursing students. The participants were 136 nursing college students in the Jeonbuk region. Data was collected in September 2020 via a structured questionnaire survey. The data was analyzed using the SPSS/23.0 program. The analysis used descriptive statistics, Pearson's correlation coefficient, independent t-test, one-way ANOVA, multiple regression analysis, and Sobel's tests. The results showed that emotional intelligence was a circle activity (F=3.13, p=.047), and motivation to nursing (F=4.16, p=.008). Resilience was a circle activity (F=5.50, p=.005), and nursing major satisfaction (t=2.19, p=.031). Career decision-making self-efficacy showed significant differences in grade (F=3.12, p=.048) and major satisfaction (t=2.36, p=.020). Emotional intelligence and resilience (r=.63, p<.001), emotional intelligence and career decision-making self-efficacy (r=.67, p<.001), resilience and career decision-making self-efficacy (r=.76, p<.001) showed significant static correlation. In emotional intelligence and career decision-making self-efficacy, resilience had a partial mediating effect (Z=6.48, p<.001), and explanatory power was 62.2%. Based on the results of this study, to improve the emotional intelligence and career decision-making self-efficacy of nursing students, it is necessary to develop a personalized and resilience-enhanced education program.

Generation of radar rainfall data for hydrological and meteorological application (I) : bias correction and estimation of error distribution (수문기상학적 활용을 위한 레이더 강우자료 생산(I) : 편의보정 및 오차분포 산정)

  • Kim, Tae-Jeong;Lee, Dong-Ryul;Jang, Sang-Min;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.50 no.1
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    • pp.1-15
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    • 2017
  • Information on radar rainfall with high spatio-temporal resolution over large areas has been used to mitigate climate-related disasters such as flash floods. On the other hand, a well-known problem associated with the radar rainfall using the Marshall-Palmer relationship is the underestimation. In this study, we develop a new bias correction scheme based on the quantile regression method. This study employed a bivariate copula function method for the joint simulation between radar and ground gauge rainfall data to better characterize the error distribution. The proposed quantile regression based bias corrected rainfall showed a good agreement with that of observed. Moreover, the results of our case studies suggest that the copula function approach was useful to functionalize the error distribution of radar rainfall in an effective way.

Evaluation method of motion seasickness by ship motions during underway in irregular waves (선박운항 중 선체동요에 의한 뱃멀미 평가방법)

  • Choi, Chan-Moon;Lee, Chang-Heon;Kim, Byung-Yeob;Ahn, Jang-Young;Kim, Seok-Jong;Shigehiro, Ritsuo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.1
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    • pp.71-78
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    • 2015
  • In order to deduce an objective evaluation method of motion seasickness incidence (MSI) by ship motions during underway in irregular waves and to present the fundamental data of passenger comfort on the yacht and the passenger ship according to the result, the MSI of the trainees by the questionnaires was analysed and compared with the rate of variation of salivary ${\alpha}$-amylase activity (VSAA) on the training ship "A-ra ho" of Jeju national university. Relationship between rate of variation (x) by salivary ${\alpha}$-amylase activity and motion seasickness incidence (y) was described by the equation, MSI(%) = 0.6073 x + 12.189 including the correlation coefficient ($R^2=0.9853$). The result obtained through the rate of variation of salivary ${\alpha}$-amylase activity which was the quantitative evaluation method for ship motions causing seasickness was most affected by z-vertical acceleration and occurred within the frequency range 0.1 to 0.3Hz centered on 0.2Hz, and the simulation result based on this finding showed the motion seasickness rate at approximately 4% lower than the rate obtained through the survey.

Feasibility of Fabricating Variable Density Phantoms Using 3D Printing for Quality Assurance (QA) in Radiotherapy

  • Oh, Se An;Kim, Min Jeong;Kang, Ji Su;Hwang, Hyeon Seok;Kim, Young Jin;Kim, Seong Hoon;Park, Jae Won;Yea, Ji Woon;Kim, Sung Kyu
    • Progress in Medical Physics
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    • v.28 no.3
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    • pp.106-110
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    • 2017
  • The variable density phantom fabricated with varying the infill values of 3D printer to provide more accurate dose verification of radiation treatments. A total of 20 samples of rectangular shape were fabricated by using the $Finebot^{TM}$ (AnyWorks; Korea) Z420 model ($width{\times}length{\times}height=50mm{\times}50mm{\times}10mm$) varying the infill value from 5% to 100%. The samples were scanned with 1-mm thickness using a Philips Big Bore Brilliance CT Scanner (Philips Medical, Eindhoven, Netherlands). The average Hounsfield Unit (HU) measured by the region of interest (ROI) on the transversal CT images. The average HU and the infill values of the 3D printer measured through the 2D area profile measurement method exhibited a strong linear relationship (adjusted R-square=0.99563) in which the average HU changed from -926.8 to 36.7, while the infill values varied from 5% to 100%. This study showed the feasibility fabricating variable density phantoms using the 3D printer with FDM (Fused Deposition Modeling)-type and PLA (Poly Lactic Acid) materials.

Genetic Differentiation of Chinese Indigenous Meat Goats Ascertained Using Microsatellite Information

  • Ling, Y.H.;Zhang, X.D.;Yao, N.;Ding, J.P.;Chen, H.Q.;Zhang, Z.J.;Zhang, Y.H.;Ren, C.H.;Ma, Y.H.;Zhang, X.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.2
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    • pp.177-182
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    • 2012
  • To investigate the genetic diversity of seven Chinese indigenous meat goat breeds (Tibet goat, Guizhou white goat, Shannan white goat, Yichang white goat, Matou goat, Changjiangsanjiaozhou white goat and Anhui white goat), explain their genetic relationship and assess their integrity and degree of admixture, 302 individuals from these breeds and 42 Boer goats introduced from Africa as reference samples were genotyped for 11 microsatellite markers. Results indicated that the genetic diversity of Chinese indigenous meat goats was rich. The mean heterozygosity and the mean allelic richness (AR) for the 8 goat breeds varied from 0.697 to 0.738 and 6.21 to 7.35, respectively. Structure analysis showed that Tibet goat breed was genetically distinct and was the first to separate and the other Chinese goats were then divided into two sub-clusters: Shannan white goat and Yichang white goat in one cluster; and Guizhou white goat, Matou goat, Changjiangsanjiaozhou white goat and Anhui white goat in the other cluster. This grouping pattern was further supported by clustering analysis and Principal component analysis. These results may provide a scientific basis for the characteristization, conservation and utilization of Chinese meat goats.

The mediating effect of life stress on the relationship between paramedic student's health behavior and bioethics awareness (응급구조학과 학생의 건강행위와 생명윤리의식의 관계에서 생활스트레스의 매개효과)

  • Lee, Eun-Young;Kim, Jung Sun;Lee, Hyo-Cheol;Ko, Dae-Sik;Kang, Kwang-Soon;Kim, Chul-Tae
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.3
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    • pp.97-110
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    • 2019
  • Purpose: This study aimed to investigate the role of life stress in the relation between health behaviors and bioethics awareness among paramedic students. Methods: This study recruited 238 paramedic students in F and R areas as participants. Multiple regression analysis was performed using Baron and Kenny's three-step procedure. Results: In the first stage, health behaviors had a significant effect on life stress (β=-.202, p<.01). In the second stage, health behaviors had a significant effect on bioethics awareness (β=.240, p<.001). In the third stage, life stress had a significant influence on bioethics awareness (β=-.167, p<.01). In the fourth stage, the regression coefficient of the third stage (β=.137) was less than that of the second stage (β=.159). In addition, when controlling for life stress, health behavior was shown to affect bioethics awareness (β=.206, p<.01). The mediating effect of life stress was found to be significant in the relation between health behavior and bioethics awareness (Z=2.04, p<.05). Conclusion: As health behavior is a factor that affects bioethics awareness through the mediation of living stress, universities should prepare training programs to improve the health behavior and reduce the life stress among students.

Discovery of novel haplotypes from wild populations of Kappaphycus (Gigartinales, Rhodophyta) in the Philippines

  • Roleda, Michael Y.;Aguinaldo, Zae-Zae A.;Crisostomo, Bea A.;Hinaloc, Lourie Ann R.;Projimo, Vicenta Z.;Dumilag, Richard V.;Lluisma, Arturo O.
    • ALGAE
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    • v.36 no.1
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    • pp.1-12
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    • 2021
  • As the global demand for the carrageenophyte Kappaphycus is steadily increasing, its overall productivity, carrageenan quality, and disease resistance are gradually declining. In the face of this dilemma, wild Kappaphycus populations are viewed as sources of new cultivars that could potentially enhance production; therefore, assessment of their diversity is crucial. This study highlights the morphological and genetic diversity of wild Kappaphycus species obtained from two sites in the Philippines. Nucleotide alignments of available 5' region of the mitochondrial cytochrome c oxidase subunit I (COI-5P) and cox2-3 spacer sequences of Kappaphycus confirmed the presence of K. alvarezii in Guiuan, Eastern Samar and K. striatus in Bolinao, Pangasinan. Based on the concatenated sequences of the COI-5P and the cox2-3 spacer, nine novel haplotypes were observed along with other published haplotypes. However, there was no relationship between haplotype and morphology. These newly recognized haplotypes indicate a reservoir of unutilized wild genotypes in the Philippines, which could be taken advantage of in developing new cultivars with superior traits. DNA barcodes generated from this study effectively expand the existing databank of Kappaphycus sequences and can provide insights in elucidating the genetic diversity of Kappaphycus species in the country.

Self-Differentiation and Mental Health of Elderly Couples (노년기 부부의 자기분화와 정신건강에 관한 연구)

  • Lee, Juyeon;Chung, Hyejeong
    • 한국노년학
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    • v.29 no.4
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    • pp.1629-1644
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    • 2009
  • This study was to examine the relationship between self-differentiation and mental health of elderly couples. This study also tries to investigate the effect of self-differentiation on mental health. Data were collected using self-administered questionnaire method with 271 elderly couples over 55 years old who lived in Chollabuk-Do province. The results showed that first, there was no significant difference in the level of total self-differentiation between husbands and wives. While the level of mental health(depression, somatization) were higher for wives than for husbands. Second, both husbands' and wives' mental health were negatively correlated with self-differentiation. Finally, results of multiple regression analyses showed that both husbands' and wives' mental health were negatively influenced by self-differentiation. Specifically, the variable significant affecting the husbands' mental health was the emotional reactivity of self-differentiation and the variable significant wives' mental health was the emotional cut-off of self-differentiation. These findings confirmed the concept of self-differentiation in applying to mental health of elderly couples.

Characteristics of Environmental Factors and Vegetation Community of Zabelia tyaihyonii (Nakai) Hisauti & H.Hara among the Target Plant Species for Conservation in Baekdudaegan (백두대간 중점보전종인 댕강나무의 식생 군집 및 환경인자 특성)

  • Kim, Ji-Dong;Lee, Hye-Jeong;Lee, Dong-Hyuk;Byeon, Jun Gi;Park, Byeong Joo;Heo, Tae-Im
    • Journal of Korean Society of Forest Science
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    • v.111 no.2
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    • pp.201-223
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    • 2022
  • Currently, species extinctions are increasing due to climate change and continued anthropogenic impact. We selected 300 species for conservation with emphasis on plants co-occurring in the Baekdudaegan area, which is a large ecological axis of Korea. We aimed to investigate the vegetation community and environmental characteristics of Zabelia tyaihyonii in the limestone habitat among the target plant species in the Baekdudaegan region to derive effective conservation strategies. In Danyang-gun, Yeongwol-gun, and Jecheon-si, we selected 36 investigation sites where Z. tyaihyonii was present. We investigated the vegetation, flora, soil and physical environment. We also found notable plants such as Thalictrum petaloideum, Sillaphyton podagraria, and Neillia uekii at the investigation sites. We classified forest vegetation community types into 4 vegetation units and 7 species group types. With canonical correspondence analysis (CCA) of the vegetation community and habitat factors, we determined the overall explanatory power to be 75.2%, and we classified the environmental characteristics of the habitat of Z. tyaihyonii into a grouping of three. Among these, we detected a relationship between the environmental factors elevation, slope, organic matter, rock ratio, pH, potassium, and sodium. We identified numerous rare and endemic plants, including Thalictrum petaloideum, in the investigation site, and determined that these groups needed to be preserved at the habitat level. In the classification of the vegetation units analyzed based on the emerging plants and the CCA, we reaffirmed the uniqueness and specificity of the vegetation community in the habitat of Z. tyaihyonii. We anticipate that our results will be used as scientific evidence for the empirical conservation of the native habitats of Z. tyaihyonii.