• Title/Summary/Keyword: Quantitative research

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Combining Conditional Generative Adversarial Network and Regression-based Calibration for Cloud Removal of Optical Imagery (광학 영상의 구름 제거를 위한 조건부 생성적 적대 신경망과 회귀 기반 보정의 결합)

  • Kwak, Geun-Ho;Park, Soyeon;Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1357-1369
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    • 2022
  • Cloud removal is an essential image processing step for any task requiring time-series optical images, such as vegetation monitoring and change detection. This paper presents a two-stage cloud removal method that combines conditional generative adversarial networks (cGANs) with regression-based calibration to construct a cloud-free time-series optical image set. In the first stage, the cGANs generate initial prediction results using quantitative relationships between optical and synthetic aperture radar images. In the second stage, the relationships between the predicted results and the actual values in non-cloud areas are first quantified via random forest-based regression modeling and then used to calibrate the cGAN-based prediction results. The potential of the proposed method was evaluated from a cloud removal experiment using Sentinel-2 and COSMO-SkyMed images in the rice field cultivation area of Gimje. The cGAN model could effectively predict the reflectance values in the cloud-contaminated rice fields where severe changes in physical surface conditions happened. Moreover, the regression-based calibration in the second stage could improve the prediction accuracy, compared with a regression-based cloud removal method using a supplementary image that is temporally distant from the target image. These experimental results indicate that the proposed method can be effectively applied to restore cloud-contaminated areas when cloud-free optical images are unavailable for environmental monitoring.

A Real-time Correction of the Underestimation Noise for GK2A Daily NDVI (GK2A 일단위 NDVI의 과소추정 노이즈 실시간 보정)

  • Lee, Soo-Jin;Youn, Youjeong;Sohn, Eunha;Kim, Mija;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1301-1314
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    • 2022
  • Normalized Difference Vegetation Index (NDVI) is utilized as an indicator to represent the vegetation condition on the land surface in various applications such as land cover, crop yield, agricultural drought, soil moisture, and forest disaster. However, satellite optical sensors for visible and infrared rays cannot see through the clouds, so the NDVI of the cloud pixel is not a valid value for the land surface. This study proposed a real-time correction of the underestimation noise for GEO-KOMPSAT-2A (GK2A) daily NDVI and made sure its feasibility through the quantitative comparisons with Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI and the qualitative interpretation of time-series changes. The underestimation noise was effectively corrected by the procedures such as the time-series correction considering vegetation phenology, the outlier removal using long-term climatology, and the gap filling using rigorous statistical methods. The correlation with MODIS NDVI was higher, and the difference was lower, showing a 32.7% improvement compared to the original NDVI product. The proposed method has an extensibility for use in other satellite products with some modification.

Ginsenoside Rg1 alleviates Aβ deposition by inhibiting NADPH oxidase 2 activation in APP/PS1 mice

  • Zhang, Han;Su, Yong;Sun, Zhenghao;Chen, Ming;Han, Yuli;Li, Yan;Dong, Xianan;Ding, Shixin;Fang, Zhirui;Li, Weiping;Li, Weizu
    • Journal of Ginseng Research
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    • v.45 no.6
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    • pp.665-675
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    • 2021
  • Background: Ginsenoside Rg1 (Rg1), an active ingredient in ginseng, may be a potential agent for the treatment of Alzheimer's disease (AD). However, the protective effect of Rg1 on neurodegeneration in AD and its mechanism of action are still incompletely understood. Methods: Wild type (WT) and APP/PS1 AD mice, from 6 to 9 months old, were used in the experiment. The open field test (OFT) and Morris water maze (MWM) were used to detect behavioral changes. Neuronal damage was assessed by hematoxylin and eosin (H&E) and Nissl staining. Immunofluorescence, western blotting, and quantitative real-time polymerase chain reaction (q-PCR) were used to examine postsynaptic density 95 (PSD95) expression, amyloid beta (Aβ) deposition, Tau and phosphorylated Tau (p-Tau) expression, reactive oxygen species (ROS) production, and NAPDH oxidase 2 (NOX2) expression. Results: Rg1 treatment for 12 weeks significantly ameliorated cognitive impairments and neuronal damage and decreased the p-Tau level, amyloid precursor protein (APP) expression, and Aβ generation in APP/PS1 mice. Meanwhile, Rg1 treatment significantly decreased the ROS level and NOX2 expression in the hippocampus and cortex of APP/PS1 mice. Conclusions: Rg1 alleviates cognitive impairments, neuronal damage, and reduce Aβ deposition by inhibiting NOX2 activation in APP/PS1 mice.

Risk Factors for COVID-19 Infection Among Healthcare Workers. A First Report From a Living Systematic Review and meta-Analysis

  • Dzinamarira, Tafadzwa;Nkambule, Sphamandla Josias;Hlongwa, Mbuzeleni;Mhango, Malizgani;Iradukunda, Patrick Gad;Chitungo, Itai;Dzobo, Mathias;Mapingure, Munyaradzi Paul;Chingombe, Innocent;Mashora, Moreblessing;Madziva, Roda;Herrera, Helena;Makanda, Pelagia;Atwine, James;Mbunge, Elliot;Musuka, Godfrey;Murewanhema, Grant;Ngara, Bernard
    • Safety and Health at Work
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    • v.13 no.3
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    • pp.263-268
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    • 2022
  • Health care workers (HCWs) are more than ten times more likely to be infected with coronavirus infectious disease 2019 (COVID-19) than the general population, thus demonstrating the burden of COVID-19 among HCWs. Factors that expose HCWs to a differentially high-risk of COVID-19 acquisition are important to elucidate, enable appropriate public health interventions to mitigate against high risk and reduce adverse outcomes from the infection. We conducted a systematic review and meta-analysis to summarize and critically analyze the existing evidence on SARS-CoV-2 risk factors among HCWs. With no geographical limitation, we included studies, in any country, that reported (i) the PCR laboratory diagnosis of COVID-19 as an independent variable (ii) one or more COVID-19 risk factors among HCWs with risk estimates (relative risk, odds ratio, or hazard ratio) (iii) original, quantitative study design, and published in English or Mandarian. Our initial search resulted in 470 articles overall, however, only 10 studies met the inclusion criteria for this review. Out of the 10 studies included in the review, inadequate/lack of protective personal equipment, performing tracheal intubation, and gender were the most common risk factors of COVID-19. Based on the random effects adjusted pooled relative risk, HCWs who reported the use of protective personal equipment were 29% (95% CI: 16% to 41%) less likely to test positive for COVID-19. The study also revealed that HCWs who performed tracheal intubations were 34% (95% CI: 14% to 57%) more likely to test positive for COVID-19. Interestingly, this study showed that female HCWs are at 11% higher risk (RR 1.11 95% CI 1.01-1.21) of COVID-19 than their male counterparts. This article presents initial findings from a living systematic review and meta-analysis, therefore, did not yield many studies; however, it revealed a significant insight into better understanding COVID-19 risk factors among HCWs; insights important for devising preventive strategies that protect them from this infection.

Quantitative analysis of drought propagation probabilities combining Bayesian networks and copula function (베이지안 네트워크와 코플라 함수의 결합을 통한 가뭄전이 발생확률의 정량적 분석)

  • Shin, Ji Yae;Ryu, Jae Hee;Kwon, Hyun-Han;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.54 no.7
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    • pp.523-534
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    • 2021
  • Meteorological drought originates from a precipitation deficiency and propagates to agricultural and hydrological droughts through the hydrological cycle. Comparing with the meteorological drought, agricultural and hydrological droughts have more direct impacts on human society. Thus, understanding how meteorological drought evolves to agricultural and hydrological droughts is necessary for efficient drought preparedness and response. In this study, meteorological and hydrological droughts were defined based on the observed precipitation and the synthesized streamflow by the land surface model. The Bayesian network model was applied for probabilistic analysis of the propagation relationship between meteorological and hydrological droughts. The copula function was used to estimate the joint probability in the Bayesian network. The results indicated that the propagation probabilities from the moderate and extreme meteorological droughts were ranged from 0.41 to 0.63 and from 0.83 to 0.98, respectively. In addition, the propagation probabilities were highest in autumn (0.71 ~ 0.89) and lowest in winter (0.41 ~ 0.62). The propagation probability increases as the meteorological drought evolved from summer to autumn, and the severe hydrological drought could be prevented by appropriate mitigation during that time.

Comparison of Internal and External Frameworks for Units on Magnets in Elementary Science Textbooks First Developed by the Authorization System (검정제에 의해 최초 개발된 초등과학교과서들의 자석 단원에 대한 내외적 체제 비교)

  • Seongsoo, Jeon
    • Journal of The Korean Association For Science Education
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    • v.42 no.5
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    • pp.525-542
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    • 2022
  • The purpose of this study is to comparatively analyze the internal and external frameworks of elementary science textbooks, which first appeared as the authorization system of elementary science textbooks changed from the national government system. In order to confirm the purpose of the authorization system to support the development of diverse and creative textbooks, this study compared 7 authorized textbooks with the national textbook developed as the 'Use of Magnets' unit of the 2015 revised science curriculum. In this study, the textbook's framework was largely divided into an external framework and an internal framework for the 'Use of Magnets' unit of elementary science textbooks, and quantitative and qualitative analyses were conducted in parallel according to each subcategory. According to the research results, in the external framework of textbook units, all textbooks had the same structure: unit introduction, scientific inquiry, creative convergence, unit arrangement, and scientific reading materials. The framework in the 'Use of Magnets' unit of the 7 types of authorized textbooks was found to have some differences according to the textbook development team's interpretation of the curriculum achievement standards and many commonalities that maintained the framework in the national textbooks. In addition, the characteristics of each textbook were clearly revealed in some areas not specified in curriculum such as unit introduction activities and science reading materials, a meaningful change was also found in that the level of inquiry activity was classified and operated in response to the uniform inquiry activity operation of the existing government textbooks.

Comparison of Job Satisfaction among Employees according to Hospital Type (병원 형태에 따른 재직자 만족도 비교연구)

  • Kim, Cheol;Kwang-Hwan, Kim;Byoung Kwon, Lee;Hey-Jeong, Hwang
    • Journal of Digital Policy
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    • v.1 no.2
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    • pp.71-77
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    • 2022
  • The purpose of this study is to analyze the job satisfaction of hospital workers according to the type of hospital and to provide basic data for successful hospital management. For data analysis, frequency analysis and chi-square analysis are performed for general characteristics, and Kendall's tau correlation analysis is performed to see the correlation between statistically significant factors among job environment, value realization, organizational characteristics, and individual ability factors. did A total of 241 people working at primary, secondary, and tertiary medical institutions were surveyed. Among the value realization factors in the research results, self-esteem and rewarding (p<0.05), autonomy and creativity (p<0.05), and among personal competencies factors, workload (p<0.05) were statistically A significant difference was seen. Value realization and personal competence factors were found to influence job satisfaction (p<0.001). In conclusion, the most basic for the qualitative and quantitative growth of the hospital should be the job satisfaction of the internal members, on the basis of which positive medical services should be provided to the patients.

Comparative Study on Anti-inflammatory Effects and Compound Contents of Multi-herbal Extracts HT008 produced by Different Manufacturing Methods (한약복합추출물 HT008의 제조방법에 따른 항염증 효능 및 성분함량 비교연구)

  • Lee, Donghun;Song, Jungbin;Song, Mikyung;Gaire, Bhakta Prasad;Park, Juyeon;Jin, Aihong;Choi, Ho-Young;Kim, Hocheol
    • The Korea Journal of Herbology
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    • v.28 no.4
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    • pp.71-76
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    • 2013
  • Objectives : The biological activities and compound contents of herbal medicine vary depending on manufacturing processes. In this study, we compared anti-inflammatory effects and compound contents of three kinds of multi-herbal extract HT008 produced by different manufacturing processes in order to determine chemical and biological equivalence. Methods : HT008 was produced by three different manufacturing methods: 1. Freeze dried extract of Eleutherococcus senticosus, Scutellaria baicalensis and Angelica sinensis (HT008 FD), 2. Spray dried extract of E. senticosus and S. baicalensis combined with reflux extract of A. sinensis (HT008 SD), 3. Spray dried extract of E. senticosus and S. baicalensis combined with supercritial fluid extract of A. sinensis (HT008 SF). Anti-inflammatory effects were evaluated using acetic acid induced pain model and ${\lambda}$-carageenan induced paw edema model. Compound contents were evaluated by HPLC quantitative analysis of standard compounds of HT008, eleutheroside E, baicalin, z-ligustilide. Results : HT008 FD, HT008 SD and HT008 SF significantly decreased acetic acid induced pain index and ${\lambda}$-carrageenan induced paw edema volume compared with that of control group. There was no significant difference in efficacy among the HT008 FD, HT008 SD and HT008 SF. Standard compound contents of HT008 FD, HT008 SD and HT008 SF were quantified within the range of Korean pharmacopoeia or other research. Conclusions : Three different manufacturing methods of multi-herbal extracts have been developed without noticeable difference in the efficacy or compound contents. The results might be used to establish manufacturing process and industrialization of herbal extracts.

Ukrainian Students' Analysis of Abuse Treatment by Parents: Retrospective and Perspective in Virtual and Real Environments

  • Stoliarchuk, Olesia;Kokhanova, Olena;Prorok, Nataliia;Khrypko, Svitlana;Shevtsova, Olena;Tkachyshyna, Oksana;Lobanchuk, Olena
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.197-207
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    • 2022
  • Given the prevalence of violence in Ukrainian families, measures to prevent parental abusive treatment against children are urgent. It is important to study today's youth awareness about violence within families in order to enhance a culture of engagement with spouses and children in future. The aim of the study is to examine students' reflective experiences and their attitudes towards forms, frequency, causes and effects of parental abusive treatment. During the research the following methods were used step-by-step: theoretical analyses of scientific resources, anonymous questionnaire, quantitative and correlation analyses. According to result of survey 98 students who were interviewed, none of them fell victim of sexual abuse in their families. However, more than a half (51%) of the students surveyed experienced some forms of parental physical punishment. All the interviewed students encountered psychological cases of parental violence. The mostprevalent forms of parental abuse among the interviewees are criticism, negative comparison, emotional detachment, arrogance, intimidation, blackmail and humiliation. The most prevalent consequences of parental abuse among students are anxiety, low self-esteem, insecurity, impatience, suspiciousness, constraint in communication. Students agree that budget limitations, forced labor, criticism, spanking, emotional detachment, ignoring type of communication, reproach, blackmail are acceptable methods of punishment to use when raising their own children. These results clearly demonstrate the problem of the impact of parental abuse on children and its consequences in the future. A virtual dimension of the actualized problem is considered, namely: - virtualization of aggression and cruelty in the postmodern world. - the level of determining the factor of cruelty from the space of virtual culture. - the mirror image of everyday cruelty in the virtual environment; - the phenomenon of video games as a source and context of representation of the factor of cruelty in behavioral realities; - cybercrime as a virtualized result of cruelty in family and everyday realities. - futurological perspectives of virtualization of cruelty in communicative culture in general and in family relations in particular. The postmodern world is fundamentally different from the traditions and culture of the past, primarily due to the development of computer technologies and the virtualization of life in general. So, for example, virtual communities have become, in a certain way, another world, a second reality of life in general. And certain behavioral factors, in particular cruelty in the private environment, became a projection of such a phenomenon as cybercrime. Video games are a unique modern phenomenon, which multipolarly absorb all facets of human potential, communicative tendencies, behavioral and characterological factors, from the warmth of interpersonal relationships to the extreme degree of cruelty.

A Study on Flood Susceptibility of Heritage Sites by Heritage Type Depending on Locational Characteristics (입지특성에 따른 문화재 유형별 홍수 민감성 기초연구)

  • Kim, Ji-Soo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.3
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    • pp.46-56
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    • 2022
  • This study aimed to analyze the locational characteristics of heritage sites in Seoul in order to identify flood susceptibility by type. As for the location factors related to flood susceptibility, elevation, slope, distance to streams, and topographic location were analyzed. Literature review was supplemented for the historical and humanistic environments of heritage sites. The results of the study are as follows. First, heritage sites in Seoul are distributed throughout the city, and are especially highly dense in the Hanyangdoseong fortress. It was also confirmed that heritage sites were concentrated around Jung-gu, Jongno-gu, Jingwan-dong, and Ui-dong in the quantitative spatial analyses. Second, types of heritage sites at the circumstance susceptible to flood damage were related to commerce and distribution, traffic, modern traffic and communication, geological monument, residence, government office, and palace. Third, heritage types with locational characteristics that showed low flood susceptibility were found to be natural scenic spots, telecommunication, ceramics, Buddhism, tombs, and tomb sculptural heritage assets. In a time when risk factors that can damage the value of heritage are gradually increasing due to anthropogenic influences along with changes in the natural environment, this study provides basic data for vulnerability analysis that reflects the unique characteristics of heritage assets. The results can contribute to more comprehensive and comprehensive insights for the management and protection of heritage by including the humanities and social science data together with natural factors in the analysis.