• Title/Summary/Keyword: Multiple exposures

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Spatial Resolution and Dynamic Range Enhancement Algorithm using Multiple Exposures (복수 노출을 이용한 공간 해상도와 다이내믹 레인지 향상 알고리즘)

  • Choi, Jong-Seong;Han, Young-Seok;Kang, Moon-Gi
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.6
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    • pp.117-124
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    • 2008
  • The approaches to overcome the limited spatial resolution and the limited dynamic range of image sensors have been studied independently. A high resolution image is reconstructed from multiple low resolution observations and a wide dynamic range image is reconstructed from differently exposed multiple low dynamic range in es based on signal processing approach. In practical situations, it is reasonable to address them in a unified context because the recorded image suffers from limitations of both spatial resolution and dynamic range. In this paper, the image acquisition process including limited spatial resolution and limited dynamic range is modelled. With the image acquisition model, the response function of the imaging system is estimated and the single image of which spatial resolution and dynamic range are simultaneously enhanced is obtained. Experimental results indicate that the proposed algorithm outperforms the conventional approaches that perform the high resolution and wide dynamic range reconstruction sequentially with respect to both objective and subjective criteria.

Estimation of Interaction Effects among Nucleotide Sequence Variants in Animal Genomes

  • Lee, Chaeyoung;Kim, Younyoung
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.1
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    • pp.124-130
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    • 2009
  • Estimating genetic interaction effects in animal genomics would be one of the most challenging studies because the phenotypic variation for economically important traits might be largely explained by interaction effects among multiple nucleotide sequence variants under various environmental exposures. Genetic improvement of economic animals would be expected by understanding multi-locus genetic interaction effects associated with economic traits. Most analyses in animal breeding and genetics, however, have excluded the possibility of genetic interaction effects in their analytical models. This review discusses a historical estimation of the genetic interaction and difficulties in analyzing the interaction effects. Furthermore, two recently developed methods for assessing genetic interactions are introduced to animal genomics. One is the restricted partition method, as a nonparametric grouping-based approach, that iteratively utilizes grouping of genotypes with the smallest difference into a new group, and the other is the Bayesian method that draws inferences about the genetic interaction effects based on their marginal posterior distributions and attains the marginalization of the joint posterior distribution through Gibbs sampling as a Markov chain Monte Carlo. Further developing appropriate and efficient methods for assessing genetic interactions would be urgent to achieve accurate understanding of genetic architecture for complex traits of economic animals.

Spatial Epidemiology and Environmental Health: On the Use of Spatially Referenced Health and Environment Data (공간역학과 환경보건: 공간위치정보 활용에 대한 고찰)

  • Han, Dai-Kwon;Hwang, Seung-Sik
    • Journal of Environmental Health Sciences
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    • v.37 no.1
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    • pp.1-11
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    • 2011
  • Recent advances in Geographic Information Systems and spatial statistical and analytical methods, along with the availability of spatially referenced health and environmental data, have created unique opportunities to investigate spatial associations between environment exposures and health outcomes at multiple spatial scales and resolutions. However, the increased use of spatial data also faces challenges, one of which is to ensure certainty and accuracy of locational data that meets the needs of a study. This article critically reviews the use of spatially referenced data in epidemiologic studies, focusing on the issue of locational uncertainty generated from the process of geocoding health and environmental data. Primarily, major issues involving the use of spatially referenced data are addressed, including completeness and positional accuracy, potential source of bias and exposure misclassification, and implications for epidemiologic studies. The need for critical assessment and caution in designing and conducting spatial epidemiology studies is briefly discussed.

Characteristics of Aerosol Particle Concentration by the Versatile Aerosol Concentration Enrichment System (VACES) (VACES을 이용한 대기 중 입자상물질의 농축기술 및 특성 연구)

  • Park, Jeong-Ho
    • Journal of Environmental Science International
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    • v.21 no.11
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    • pp.1339-1348
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    • 2012
  • The versatile aerosol concentration enrichment system (VACES) have proven useful for providing elevated levels of atmospheric aerosol to human and animal exposures. In this study, we describe a VACES and tests conducted to both optimize the enhancement factor (EF) and characterize how it depends on experiment conditions. Particle number concentrations were measured from upstream and downstream of the system by scanning mobility particle sizer (SMPS) with a long differential mobility analyzer (DMA) in combination with a condensation particle counter (CPC). SMPS was used for to determine VACES particle EF. Particle EF tends to increase for higher the saturator temperature ($T_{Sat}$) and lower the condenser temperature ($T_{Con}$). $T_{Con}$ higher than $0^{\circ}C$ and $T_{Sat}$ lower than $50^{\circ}C$ was the best to obtain the most increase in particle concentration. Correlation analysis of EF with factor variables of $T_{Sat}$ and $T_{Con}$ resulted in correlation 0.662 and 0.416, respectively. With all five predictor variables included in a multiple regression model, the EF had a liner correlation with $R^2=0.643$.

Zinc in Pancreatic Islet Biology, Insulin Sensitivity, and Diabetes

  • Maret, Wolfgang
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.1-8
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    • 2017
  • About 20 chemical elements are nutritionally essential for humans with defined molecular functions. Several essential and nonessential biometals are either functional nutrients with antidiabetic actions or can be diabetogenic. A key question remains whether changes in the metabolism of biometals and biominerals are a consequence of diabetes or are involved in its etiology. Exploration of the roles of zinc (Zn) in this regard is most revealing because 80 years of scientific discoveries link zinc and diabetes. In pancreatic ${\beta}$- and ${\alpha}$-cells, zinc has specific functions in the biochemistry of insulin and glucagon. When zinc ions are secreted during vesicular exocytosis, they have autocrine, paracrine, and endocrine roles. The membrane protein ZnT8 transports zinc ions into the insulin and glucagon granules. ZnT8 has a risk allele that predisposes the majority of humans to developing diabetes. In target tissues, increased availability of zinc enhances the insulin response by inhibiting protein tyrosine phosphatase 1B, which controls the phosphorylation state of the insulin receptor and hence downstream signalling. Inherited diseases of zinc metabolism, environmental exposures that interfere with the control of cellular zinc homeostasis, and nutritional or conditioned zinc deficiency influence the pathobiochemistry of diabetes. Accepting the view that zinc is one of the many factors in multiple gene-environment interactions that cause the functional demise of ${\beta}$-cells generates an immense potential for treating and perhaps preventing diabetes. Personalized nutrition, bioactive food, and pharmaceuticals targeting the control of cellular zinc in precision medicine are among the possible interventions.

Safety Management System on Nanomaterials with a Regulatory Scheme (나노물질 안전관리 동향 및 제도 도입에 관한 고찰)

  • Kim, Sunah;Kim, Hojung;Hong, Yongsuk
    • Journal of Environmental Policy
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    • v.12 no.3
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    • pp.49-71
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    • 2013
  • Nanomaterials, which have the issues related to toxicity, environmental exposures, and human health, have been focused on significance of their safety management. Regarding their higher applicability for multiple sectors from chemicals to consumer products, the most important thing is to consider international policy cases categorized by regulatory intensities, applicable sectors, and substance types for establishing of convincing safety management system on nanomaterials. For minimizing the nanomaterials' risk potential, developing the system that underlines a precautionary principle is also needed. Regulatory system on nanomaterials should be applicable to the status quo and be a proactive approach to rapidly changing international trends.

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Relationship between Workplace Hazard Exposures and Chronic Health Problems in Korea: The Fifth Korean Working Conditions Survey (한국근로자의 직장 내 유해인자 노출과 장기적인 건강문제의 관련성: 제5차 근로환경조사를 이용하여)

  • Kim, Yun Hee
    • Korean Journal of Occupational Health Nursing
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    • v.29 no.1
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    • pp.58-68
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    • 2020
  • Purpose: Workers with chronic health problems find it difficult to maintain their work because of socioeconomic difficulties. The purpose of this study was to evaluate the relationships between physical, ergonomic, and mental health hazards in the workplace and chronic health problems of Korean workers. Methods: A total of 28,807 wage workers participated in the study and were selected using the Fifth Korean Working Conditions Survey (2017). Multiple logistic regression analysis was used to determine the associations between physical, ergonomic, and mental health hazards and chronic health problems. Results: Of the participants, 1,220 (4.23%) had chronic health problems. Even after adjusting the general characteristics, vibration, noise, high temperature, low temperature, dust, chemical and cigarette smoke, fatigue and painful posture, dragging or pushing or moving of heavy objects, repetitive hand or arm movements, working with a computer or smartphone, use of internet or e-mail, and anxiety situations increased the risk of chronic health problems. Conclusion: The study reaffirms that exposure of physical, ergonomic, and mental health hazards in the workplace significantly increases the risk of chronic health problems.

Indoor, Outdoor, and Personal Exposure to Nitrogen Dioxide Comparing Industrial Complex Area with Country Area (공단지역과 시골지역 주택 실내, 실외 및 개인의 이산화질소 노출평가)

  • Yang, Won-Ho;Im, Sung-Guk;Son, Bu-Soon
    • Journal of Environmental Health Sciences
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    • v.34 no.3
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    • pp.183-187
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    • 2008
  • Indoor air quality can be affected by indoor sources, ventilation, decay, and outdoor levels. Various indoor and out-door combustion sources produce nitrogen dioxide ($NO_2$), which is a by-product of high temperature fossil fuel combustion. Especially, the presence of gas ranges and smoking have been identified as major factors contributing to indoor $NO_2$ exposures. In this study, we compared an industrial complex area with a country area by assessing the personal exposure to $NO_2$with measurements of indoor and outdoor $NO_2$ levels in residences and by house characteristics and questionnaire. Personal exposure concentrations were significantly correlated with indoor $NO_2$ concentrations of residences in both the industrial complex area and the country area with correlation coefficients of 0.561 and 0.664, respectively, compared to outdoors. Multiple regression analysis, indicated that indoor $NO_2$ levels in residences were only affected by outdoor levels (p = 0.000) in spite of higher indoor sources such as smoking. Therefore, it is suggested that outdoor air quality as well as indoor air quality should be considered in the reduction of the personal exposure to air pollutants.

Five Year's Follow-up of the Cardiovascular Disease Risk Factors among the Low Level Organic Solvent Exposure Workers (저농도 유기용제 노출 사업장 근로자의 심혈관질환 위험인자 변화 추적(2008~2012))

  • Kim, Mi-Ae
    • Korean Journal of Occupational Health Nursing
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    • v.24 no.2
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    • pp.67-75
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    • 2015
  • Purpose: The objective of the present study was to evaluate the effects of occupational exposure to low dose organic solvents on the prevalence of cardiovascular risk factors. Methods: Study design was retrospective cohort study subjected on 191 exposures and 118 controls working in a petrochemical manufacture company. The eight indicators related to CVD risk were followed up for five years from 2008 to 2012. The risk level was compared during the follow up years and subject's characteristics, and the change of risk level were analyzed with repeated measures ANOVA and multiple logistic regression analysis. Results: At the start year 2008, the rate over cutoff value (ROCV) of BS (p<.001) and mean systolic BP (p=.017) were higher in organic solvent exposure group and the others showed no difference. And by the subject's characteristics, odds ratio of the ROCV of BS were higher in organic solvent exposure group and work shift group as 2.51 and 3.07. Comparing the results in 2012 to those of 2008, cardiovascular disease risk in organic solvent exposure group was about 1.5 times higher than that of in the control group. Conclusion: Gradual increase in the CVD risk was identified in organic solvent exposure group. However, the risk might be influenced by shift work and bad behaviors rather than organic solvent exposure.

Major gene interaction identification in Hanwoo by adjusted environmental effects (환경적인 요인을 보정한 한우의 우수 유전자 조합 선별)

  • Lee, Jea-Young;Jin, Mi-Hyun
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.467-474
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    • 2012
  • Human diseases and livestock economic traits are not typically the result of variation of a single genetic locus, but are rather the result of interplay between interactions among multiple genes and a variety of environmental exposures. We have used linear regression model for adjusted environmental effects and multifactor dimensionality reduction (MDR) method to identify gene-gene interaction effect of statistical model in general. Of course, we use 5 SNPs (single uncleotide polymorphism) which were studied recently by Oh et al. (2011). We apply the MDR (multifactor demensionality reduction) method on the identify major interaction effects of single nucleotide polymorphisms responsible for economic traits in a Korean cattle population.