• Title/Summary/Keyword: Current limiting

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Climate Change and Soil-Water Balance

  • Aydin, Mehmet;Yano, Tomohisa;Haraguchi, Tomokazu;Evrendilek, Fatih;Jung, Yeong-Sang
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2011.11a
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    • pp.7-10
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    • 2011
  • The semi-arid and arid regions comprise almost 40 percent of the world's land surface. The low and erratic precipitation pattern is the single most significant contributor for limiting crop production in such regions where rainfall is the source for surface, soil and ground water. In a changing climate, the semi-arid and arid regions would increasingly face the challenge of water scarcity. According to the relevant literature; under the assumption of a doubling of the current atmospheric CO2 concentration, irrigation demand was estimated to increase for wheat and to decrease for second crop maize in a Mediterranean environment of Turkey in the 2070s. Crop evapotranspiration would decrease due to stomata closure. Reference evapotranspiration and potential soil evaporation were projected to increase by 8.0 and 7.3%, respectively, whereas actual soil evaporation was predicted to decrease by 16.5%. Drainage losses below 90 cm soil depth were found to decrease mainly due to lesser rainfall amount in the future.

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Effects of Lower Rib Expansion Limitation on Maximal Respiratory Pressure and Abdominal Muscle Activity During Maximal Breathing in Healthy Subjects

  • Lee, Gyu-wan;Yoon, Tae-Lim;Lee, Young-jung;Kim, Ki-song;Yi, Chung-hwi
    • The Journal of Korean Physical Therapy
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    • v.32 no.6
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    • pp.394-399
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    • 2020
  • Purpose: The aim of this study was to determine the effects of lower rib cage lateral expansion limitation on the maximal inspiratory and expiratory pressures and on abdominal muscle activity during maximal respiratory breathing in healthy subjects. Methods: Fifteen healthy male subjects voluntarily participated in this cross-sectional study. During maximal breathing, maximal inspiratory and expiratory pressures were measured, and abdominal muscle activity was determined with using surface electromyography. Also, the measurement was repeated with using a non-elastic belt to the lower rib cage for limiting of lateral expansion. A Wilcoxon signed-rank test was performed for obtaining the statistical difference with a significance level of 0.05. Results: The findings of this study are as follows: 1) There were no significant differences in maximal inspiratory and expiratory pressure with and without lower rib cage lateral expansion (p>0.05), 2) There was no significant difference in abdominal muscle activity during the maximal inspiratory phase (p>0.05). However, right external oblique muscle activity decreased significantly during maximum exhalation with lower rib expansion limitation (p<0.05). Conclusion: The results of the current study indicate that a non-elastic belt was effective in decreasing right external oblique muscle activity during forced expiratory breathing in healthy subjects.

Influence of Health Promotion Behavior and Perceived Health Status on the Health-related Quality of Life of Industrial Employees (산업장근로자의 건강증진행위, 지각된 건강상태가 건강관련 삶의 질에 미치는 영향)

  • Lim, Yumi;Shim, Moon Sook
    • Journal of Korean Public Health Nursing
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    • v.35 no.1
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    • pp.165-178
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    • 2021
  • Purpose: This study examined the correlations between the health promotion behavior, perceived health status, and health-related quality of life(HRQOL) to identify the factors influencing HRQOL of industrial employees, Methods: The target of this study was 126 industrial the employees in a vehicle company who understood the purpose of the study and agreed to participate. The collected data were analyzed by frequency, percentage, mean, standard deviation, independent t-test, one way ANOVA, Scheffé test and hierarchical regression analysis using SPSS 25.0 program. Results: Hierarchical regression analysis showed that the Perceived Health Status was the influencing factor of Physical Component Summary of HRQOL(��=.56, p<.001), which had an additional explanatory power of 21.2%. The influencing factor of Mental Component Summary of HRQOL was Health Promotion Behavior(��=.32, p<.001), which had an additional explanatory power of 17.2% and Perceived Health Status(��=.29, p=.002), which had an additional explanatory power of 5.1%. Conclusion: To improve the HRQOL of life of industrial employees, counseling and education that recognizes the current state of health and induces positive health awareness are necessary, and appropriate promotion programs without limiting the time and place are needed.

Dose-Dependent Inhibition of Melanoma Differentiation-Associated Gene 5-Mediated Activation of Type I Interferon Responses by Methyltransferase of Hepatitis E Virus

  • Myoung, Jinjong;Min, Kang Sang
    • Journal of Microbiology and Biotechnology
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    • v.29 no.7
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    • pp.1137-1143
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    • 2019
  • Hepatitis E virus (HEV) accounts for 20 million infections in humans worldwide. In most cases, the infections are self-limiting while HEV genotype 1 infection cases may lead to lethal infections in pregnant women (~ 20% fatality). The lack of small animal models has hampered detailed analysis of virus-host interactions and HEV-induced pathology. Here, by employing a recently developed culture-adapted HEV, we demonstrated that methyltransferase, a non-structural protein, strongly inhibits melanoma differentiation-associated gene 5 (MDA5)-mediated activation of type I interferon responses. Compared to uninfected controls, HEV-infected cells display significantly lower levels of $IFN-{\beta}$ promoter activation when assessed by luciferase assay and RT-PCR. HEV genome-wide screening showed that HEV-encoded methyltransferase (MeT) strongly inhibits MDA5-mediated transcriptional activation of $IFN-{\beta}$ and $NF-{\kappa}B$ in a dose-responsive manner whether or not it is expressed in the presence/absence of a tag fused to it. Taken together, current studies clearly demonstrated that HEV MeT is a novel antagonist of MDA5-mediated induction of $IFN-{\beta}$ signaling.

PWM Control of Reduced Switch Z-Source Inverter (스위치 저감형 Z-Source Inverter PWM 제어)

  • Kim, Seong-Hwan;Park, Tae-Sik
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.53-57
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    • 2019
  • In this paper, we propose a new Z-source inverter structure to reduce switching elements and PWM pulse control method. Z-network is connected between the inverter backplane and ground, rather than between the DC voltage and the inverter in an improved Z-source inverter. And the improved Z-source inverter has the advantages of limiting the capacitor inrush current and reducing the capacitor voltage stress. We have proposed a topology of a new type of switch-reduced improved Z-source inverter that reduces the number of switches from six to four in an improved Z-source inverter and developed a PWM control method suitable for the proposed topology. The characteristics and the performance of the proposed method were verified by using PSIM simulation.

The impacts of exercise on pediatric obesity

  • Headid, Ronald J. III;Park, Song-Young
    • Clinical and Experimental Pediatrics
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    • v.64 no.5
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    • pp.196-207
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    • 2021
  • Over the last few decades, the rates of pediatric obesity have more than doubled regardless of sociodemographic categorization, and despite these rates plateauing in recent years there continues to be an increase in the severity of obesity in children and adolescents. This review will discuss the pediatric obesity mediated cardiovascular disease (CVD) risk factors such as attenuated levels of satiety and energy metabolism hormones, insulin resistance, vascular endothelial dysfunction, and arterial stiffness. Additionally, early intervention to combat pediatric obesity is critical as obesity has been suggested to track into adulthood, and these obese children and adolescents are at an increased risk of early mortality. Current suggested strategies to combat pediatric obesity are modifying diet, limiting sedentary behavior, and increasing physical activity. The effects of exercise intervention on metabolic hormones such as leptin and adiponectin, insulin sensitivity/resistance, and body fat in obese children and adolescents will be discussed along with the exercise modality, intensity, and duration. Specifically, this review will focus on the differential effects of aerobic exercise, resistance training, and combined exercise on the cardiovascular risks in pediatric obesity. This review outlines the evidence that exercise intervention is a beneficial therapeutic strategy to reduce the risk factors for CVD and the ideal exercise prescription to combat pediatric obesity should contain both muscle strengthening and aerobic components with an emphasis on fat mass reduction and long-term adherence.

Current perspectives on atypical pneumonia in children

  • Shim, Jung Yeon
    • Clinical and Experimental Pediatrics
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    • v.63 no.12
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    • pp.469-476
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    • 2020
  • The major pathogens that cause atypical pneumonia are Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila. Community-acquired pneumonia (CAP) caused by M. pneumoniae or C. pneumoniae is common in children and presents as a relatively mild and self-limiting disease. CAP due to L. pneumophila is very rare in children and progresses rapidly, with fatal outcomes if not treated early. M. pneumoniae, C. pneumoniae, and L. pneumophila have no cell walls; therefore, they do not respond to β-lactam antibiotics. Accordingly, macrolides, tetracyclines, and fluoroquinolones are the treatments of choice for atypical pneumonia. Macrolides are the first-line antibiotics used in children because of their low minimum inhibitory concentrations and high safety. The incidence of pneumonia caused by macrolide-resistant M. pneumoniae that harbors point mutations has been increasing since 2000, particularly in Korea, Japan, and China. The marked increase in macrolide-resistant M. pneumoniae pneumonia (MRMP) is partly attributed to the excessive use of macrolides. MRMP does not always lead to clinical nonresponsiveness to macrolides. Furthermore, severe complicated MRMP responds to corticosteroids without requiring a change in antibiotic. This implies that the hyper-inflammatory status of the host can induce clinically refractory pneumonia regardless of mutation. Empirical macrolide therapy in children with mild to moderate CAP, particularly during periods without M. pneumoniae epidemics, may not provide additional benefits over β-lactam monotherapy and can increase the risk of MRMP.

A Study on the Direction of User Participatory Design for School using Socio-Spatial Network Analysis - Focused on the middle and high school in Seoul - (사회-공간 네트워크 분석을 활용한 학교설계 사용자 참여디자인 방향에 관한 연구 - 서울시 중, 고등학교 사례를 중심으로 -)

  • Shin, Doosik;Cho, Tae-Ho;Jeon, Young-Hoon
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.10
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    • pp.19-30
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    • 2019
  • The purpose of this study is to explore ways to efficiently capture the opinions of students who are main users in the planning, planning and design of school facilities. There are many criteria for determining good schools, but in this study, the main purpose of this study was to set up the main users as students, and to analyze the differences between the network and the actual spatial structure (network) created by the hope of students' use of school space, and the direction to overcome the differences. After surveying students' opinions about their satisfaction with school space and their desire to use school space by limiting the survey target to middle and high schools in Seoul, the 'social-space network analysis' was recently established in the social science field. As a result, it was found that the proximity of space and space desired by students in the school varied greatly depending on the geographical conditions, school districts, and the status of the current facilities, and the direction of improvement specialized for each school was found.

Ethylenediamine Based Surface Defect Passivation for Enhancing Indoor Photovoltaic Efficiency of Perovskite (페로브스카이트 실내 광전변환 효율 향상을 위한 ethylenediamine 기반의 표면 결함 부동화 연구)

  • Seok Beom Kang;Joo Woong Yoon;Chang Yong Kim;Sangheon Lee;Hyemin Lee;Dong Hoe Kim
    • Current Photovoltaic Research
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    • v.11 no.3
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    • pp.87-95
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    • 2023
  • As the demand for the Internet of Things grows, research into indoor photovoltaics for wireless power is becoming important. In particular, perovskite has attracted considerable attention due to its superior performance compared to other candidates. However, various surface defects present in perovskite are a limiting factor for high performance. In particular, deep-level surface defects caused by uncoordinated Pb2+ ions directly limit charge transport. In low light environments, this appears to be a more significant hurdle. In this study, ethylenediamine, which can provide covalent bonding to uncoordinated Pb2+ ions through nitrogen, was used as a surface treatment material for indoor photovoltaics. X-ray photoelectron spectroscopy confirmed that the uncoordinated Pb2+ ions were effectively passivated by the terminal nitrogen of ethylenediamine. As a consequence, a VOC of 0.998 V, a JSC of 0.139 mA cm-2 and a fill factor of 83.03% were achieved, resulting in an indoor photoelectric conversion efficiency of 38.02%.

Identification of Drought Tolerant Genotypes by Evaluating Morpho-physiological Traits in Pepper

  • Kyu Kyu Thin;Alebel Mekuriaw;Hyerim Do;Inhwa Yeam;Je Min Lee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2022.09a
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    • pp.29-29
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    • 2022
  • The fast-changing climatic conditions make plants to be vulnerable to many abiotic stresses. Drought stress is one of the limiting factors that affect pepper production in water deficient regions. It affects plant growth and development by altering physiological, morphological, and metabolic processes. Breeding drought tolerant varieties is one of the mitigation strategies to overcome the ever increasing drought disaster. Hence, screening of new drought tolerant pepper genotypes is essential. The current study was aimed to identify new drought tolerant genotypes among the collection of pepper genetic resources. In total, 70 pepper genotypes were screened for drought tolerance after exposure to drought stress condition. The pepper genotypes were classified as highly tolerant, intermediate, or severely sensitive to drought stress based on the phenotypic analysis. Consequently, 13 genotypes significantly exhibited higher recovery rate after drought stress and were classified as highly tolerant. Comparative analysis of morphological and physiological parameters and expression of drought responsive genes between tolerant and susceptible pepper genotypes will be presented and discussed. The identified tolerant genotypes will be useful resources for breeding drought tolerant pepper cultivars.

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