• 제목/요약/키워드: correlated parameters

검색결과 1,257건 처리시간 0.036초

Optimal earthquake intensity measures for probabilistic seismic demand models of ARP1400 reactor containment building

  • Nguyen, Duy-Duan;Thusa, Bidhek;Azad, Md Samdani;Tran, Viet-Linh;Lee, Tae-Hyung
    • Nuclear Engineering and Technology
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    • 제53권12호
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    • pp.4179-4188
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    • 2021
  • This study identifies efficient earthquake intensity measures (IMs) for seismic performances and fragility evaluations of the reactor containment building (RCB) in the advanced power reactor 1400 (APR1400) nuclear power plant (NPP). The computational model of RCB is constructed using the beam-truss model (BTM) for nonlinear analyses. A total of 90 ground motion records and 20 different IMs are employed for numerical analyses. A series of nonlinear time-history analyses are performed to monitor maximum floor displacements and accelerations of RCB. Then, probabilistic seismic demand models of RCB are developed for each IM. Statistical parameters including coefficient of determination (R2), dispersion (i.e. standard deviation), practicality, and proficiency are calculated to recognize strongly correlated IMs with the seismic performance of the NPP structure. The numerical results show that the optimal IMs are spectral acceleration, spectral velocity, spectral displacement at the fundamental period, acceleration spectrum intensity, effective peak acceleration, peak ground acceleration, A95, and sustained maximum acceleration. Moreover, weakly related IMs to the seismic performance of RCB are peak ground displacement, root-mean-square of displacement, specific energy density, root-mean-square of velocity, peak ground velocity, Housner intensity, velocity spectrum intensity, and sustained maximum velocity. Finally, a set of fragility curves of RCB are developed for optimal IMs.

Schmidt hammer 반발지수로 울산지역 퇴적암의 공학적 특성을 추정하기 위한 연구 (A Prediction of Engineering Properties of Ulsan Sedimentary Rocks with Schmidt Hammer Rebound Number)

  • 민덕기;문종규
    • 한국지반공학회논문집
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    • 제22권10호
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    • pp.139-150
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    • 2006
  • 울산분지 퇴적암을 대상으로 Schmidt hammer 타격시험을 시행하여 일축 압축강도, 압열 인장강도, 탄성계수, 흡수율 및 간극율과의 상호 관계를 구명하였다. 기 연구된 결과는 여러 암종이 혼합된 결과로 실용적 적용에 어려움이 있어 지질학적 생성배경의 차이로 인한 원인을 배제하고 실용적 적용에 유용하도록 울산분지 퇴적암만을 대상으로 하여 연구를 시행하였다. Schmidt 햄머 반발지수와 각 실험결과상호간에 높은 상관성이 있으며 본 연구 결과 값으로 상호 교차검정을 한 결과도 만족할 수 있는 결과가 도출되었다.

HI superprofiles of galaxies from THINGS and LITTLE THINGS

  • Kim, Minsu;Oh, Se-Heon
    • 천문학회보
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    • 제46권2호
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    • pp.68.3-69
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    • 2021
  • We present a novel profile stacking technique based on optimal profile decomposition of a 3D spectral line data cube, and its performance test using the HI data cubes of sample galaxies from HI galaxy surveys, THINGS and LITTLE THINGS. Compared to the previous approach which aligns all the spectra of a cube using their central velocities derived from either moment analysis, single Gaussian or hermite h3 polynomial fitting, the new method makes a profile decomposition of the profiles from which an optimal number of single Gaussian components is derived for each profile. The so-called superprofile which is derived by co-adding all the aligned profiles from which the other Gaussian models are subtracted is found to have weaker wings compared to the ones constructed in a typical manner. This could be due to the reduced number of asymmetric profiles in the new method. A practical test made on the HI data cubes of the THINGS and LITTLE THINGS galaxies shows that our new method can extract more mass of kinematically cold HI components in the galaxies than the previous results. Additionally, we fit a double Gaussian model to the superprofiles whose S/N is boosted, and quantify not only their profile shapes but derive the ratio of the Gaussian model parameters, such as the intensity ratio and velocity dispersion ratio of the narrower and broader Gaussian components. We discuss how the superprofile properties of the sample galaxies are correlated with their other physical properties, including star formation rate, stellar mass, metallicity, and gas mass.

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췌장암에서 간 문맥 순환 종양 세포의 임상적인 유용성 (Clinical Utility of Portal Venous Circulating Tumor Cells in Pancreatic Cancer)

  • 윤승배;고성우
    • Journal of Digestive Cancer Research
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    • 제11권1호
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    • pp.21-29
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    • 2023
  • Despite recent advancements in the diagnosis and treatment of pancreatic cancer, clinical results remain dismal. Furthermore, there are no reliable biomarkers or alternatives beyond carbohydrate antigen 19-9. Circulating tumor cells (CTCs) may be a potential biomarker, but their therapeutic application is constrained by their rarity in peripheral venous blood. Theoretically, the portal vein can be a more appropriate location for the detection of CTCs, because the first venous drainage of pancreatic cancer is portal circulation. According to several studies, the number and detection rate of CTCs may be higher in the portal blood than in the peripheral blood. CTC counts in the portal blood are strongly correlated with several prognostic parameters such as hepatic metastasis, recurrence after surgery, and survival. The phenotypic and genotypic properties analyzed in the captured portal CTCs can assist us to comprehend tumor heterogeneity and predicting the prognosis of pancreatic cancer. The investigations to date are limited by small sample sizes and varied CTC detection techniques. Therefore, a large number of prospective studies are required to confirm portal CTCs as a valid biomarker in pancreatic cancer.

Impact of litter on femur and tibial morphology, bone biomechanics, and leg health parameters in broiler chickens

  • Komal Khan;Mehmet Kaya;Evrim Dereli Fidan;Figen Sevil Kilimci
    • Animal Bioscience
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    • 제36권9호
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    • pp.1393-1402
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    • 2023
  • Objective: In this study effects of three types of beddings on broiler leg health and bone biomechanics were evaluated. Methods: A total of 504 male chicks (Ross 308) were randomly placed on three beddings (4 replicates/group; 42 birds/pen), zeolite-added litter (ZL), plastic-grid flooring (PF), and wood shavings (WS). On day 42, chickens were weighed, slaughtered, and samples (bone, muscle, and drumstick) were collected. Bones were subjected to leg health tests, morphometric measurements, biomechanical testing, and ash analysis. Results: Broilers in PF and WS groups showed higher live weight than the ZL group (p<0.001), and the incidence of tibial dyschondroplasia (TD) and varus valgus deformity due to distal bending was significantly higher in PF (p<0.001). Multinomial logistic regression showed that bedding has a significant (p = 0.038) contribution toward the development of TD. Tibial strength (p = 0.040), drumstick width (p = 0.001), and total femur and epiphyseal ash contents (p = 0.044, 0.016) were higher in the ZL group. Chicken live weight was correlated with tibial length and weight (r = 0.762, 0.725). Conclusion: Flooring and the type of bedding material directly affect broiler bone length, strength and leg health. Plastic bedding improves the slaughter weight of chickens on the expense of leg deformities, and zeolite litter improves leg health and bone strength.

Comparison between Berkshire and crossbreed on meat quality, and investigation of the relationship with fatty acid composition and meat quality

  • Jin-Kyu Seo;Jeong-Uk Eom;Han-Sul Yang
    • Journal of Animal Science and Technology
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    • 제65권5호
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    • pp.1081-1093
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    • 2023
  • This study aimed to compare meat quality traits between Berkshire and crossbreed (Landrace × Yorkshire × Duroc), and to investigate the relationship between meat quality traits and fatty acid composition. 20 Berkshire and 20 crossbreed pigs were used to compare pork loin quality and to determine the relationship between measured variables. 23 variables were measured including proximate composition, pH, drip loss and cooking loss, Warner-Bratzler shear force, and fatty acid composition. Berkshire had higher moisture content, pH, water-holding capacity, saturated fatty acids, and redness than the crossbreed pig (p < 0.05). The fat content and polyunsaturated fatty acid were low (p < 0.05) in Berkshire. Correlation analysis showed a negatively correlation between moisture and fat content, and a positively correlation between saturated fatty acid and fat content. Moreover, saturated fatty acid and polyunsaturated fatty acid were negatively correlated. As a result of factor analysis and partial least square regression, saturated fatty acid and polyunsaturated fatty acid were estimated to be the main factors affecting quality characteristics of pork. Pig breed is associated with differences in meat quality, and fatty acid composition can have an effect on meat quality parameters.

국내 COVID-19 입원 환자의 비만, 상승된 인터루킨-6와 입원기간의 상관관계 (Correlations of obesity and elevated interleukin-6 levels with length of stay in COVID-19 patients in Korea: a retrospective study)

  • 오현정;서경산
    • Journal of Korean Biological Nursing Science
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    • 제26권2호
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    • pp.136-143
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    • 2024
  • Purpose: The purpose of this study was to investigate the associations of obesity and clinical characteristics including interleukin-6 (IL-6) with hospital length of stay (LOS) in coronavirus disease-2019 (COVID-19) patients in Korea. Methods: A retrospective descriptive study design was employed to analyze medical data from a government-designated hospital in a city of Korea. Clinical data were collected from 256 patients with COVID-19 in negative-pressure isolation wards in 2021. The following parameters were analyzed: body mass index (BMI), IL-6 levels, age, sex, comorbidities, healthy habitsat the time ofadmission, and LOS. The statistical package SPSS 26.0 was used for descriptive statistics, the independent t-test, the chi-square test, and partial correlation coefficients. Results: The age of COVID-19 patients was positively correlated with BMI (r = -.16, p = .012), IL-6 levels (r = .14, p = .022) and LOS (r = .26, p < .001). Obesity, non-drinking, hypertension, and older age were associated with longer LOS. Conclusion: These results suggest that age, obesity, and hypertension in COVID-19 patients are related to LOS. Studies investigating other factors that can affect long-term hospitalization in COVID-19 patients are suggested.

X-Ray Diffraction line profile analysis of defects and precipitates in high displacement damage neutron-irradiated austenitic stainless steels

  • Shreevalli M.;Ran Vijay Kumar;Divakar R.;Ashish K.;Padmaprabu C.;Karthik V.;Archna Sagdeo
    • Nuclear Engineering and Technology
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    • 제56권1호
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    • pp.114-122
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    • 2024
  • Irradiation-induced defects and the precipitates in the wrapper material of the Indian Fast Breeder Test Reactor (FBTR), SS 316 are analyzed using the synchrotron source-based Angle Dispersive X-Ray Diffraction (ADXRD) technique with X-rays of energy 17.185 keV (wavelength ~0.72146 Å). The differences and similarities in the high displacement damage samples as a function of dpa (displacement per atom) and dpa rate in the range of 2.9 × 10-7- 9 × 10-7 dpa/s are studied. Ferrite and M23C6 are commonly observed in the present set of high displacement damage 40-74 dpa SS 316 samples irradiated at temperatures in the range of 400-483 ℃. Also, the dislocation density has increased as a function of the irradiation dose. The X-ray diffraction peak profile parameters quantified such as peak shift and asymmetry show that the irradiation-induced defects are sensitive to the dpa rate-irradiation temperature combinations. The increase in yield strength as a function of displacement damage is also correlated to the dislocation density.

Association of daily carbohydrate intake with intermuscular adipose tissue in Korean individuals with obesity: a cross-sectional study

  • Ha-Neul Choi;Young-Seol Kim;Jung-Eun Yim
    • Nutrition Research and Practice
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    • 제18권1호
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    • pp.78-87
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    • 2024
  • BACKGROUND/OBJECTIVES: The prevalence of obesity, a worldwide pandemic, has been increasing steadily in Korea. Reports have shown that increased intermuscular adipose tissue (IMAT) is associated with an increased risk of cardiovascular disease, independent of body mass index. However, the relationship between dietary intake and IMAT accumulation in the Korean population remains undetermined. The objective of this study was to evaluate regional fat compartments using advanced magnetic resonance imaging (MRI) techniques. We also aimed to investigate the association between IMAT amounts and dietary intake, including carbohydrate intake, among Korean individuals with obesity. SUBJECTS/METHODS: This cross-sectional study, performed at a medical center in South Korea, recruited 35 individuals with obesity (15 men and 20 women) and classified them into 2 groups according to sex. Anthropometry was performed, and body fat distribution was measured using MRI. Blood parameters, including glucose and lipid profiles, were analyzed using commercial kits. Linear regression analysis was used to test whether the IMAT was associated with daily carbohydrate intake. RESULTS: Carbohydrate intake was positively associated with IMAT in all individuals, with adjustments for age, sex, height, and weight. No significant differences in blood indicators were found between the sexes. CONCLUSIONS: Regardless of sex and age, higher carbohydrate intake was strongly correlated with greater IMAT accumulation. This suggests the need to better understand sex differences and high carbohydrate diet patterns in relation to the association between obesity and metabolic risk, which may help reduce obesity prevalence.

태화강 하류에서 겨울철 조류 발생과 수질의 공간적 특성 (Winter Algal Bloom and Spatial Characteristics of Water Quality in the Lower Taewha River, Ulsan, Korea)

  • 손은락;박정임;이보라;이진우;김종설
    • 미생물학회지
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    • 제49권1호
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    • pp.30-37
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    • 2013
  • 본 연구에서는 태화강 하류에서 조수 및 조사 지점에 따른 태화강 수질 특성을 알아보고, 겨울 조류 발생에 영향을 주는 환경요인을 분석하고자 하였다. 2010년 5월에서 2011년 1월까지 태화강 하류의 신삼호교, 구삼호교, 명정천, 태화교, 명촌교 등 5개 지점에서, 사리의 만조와 간조에 시료를 채취하였다. 염분도, 용존산소(DO), 생물학적 산소 요구량(BOD), 화학적 산소 요구량(COD), 엽록소 a(Chl a), 여러 영양염류 등의 환경변수를 측정하였다. 염분도는 하류 방향으로 갈수록 증가하였으며, Chl a의 지점별 평균값은 만조 $10-26mg/m^3$, 간조 $11-53mg/m^3$였다. 특히 태화교의 경우 11월 21일-12월 22일에 Chl a 농도가 $138-296mg/m^3$로 급격히 증가하였으며, Cryptophyceae의 Rhodomonas lacustris가 우점하는 식물플랑크톤이었다. 태화교에서 Chl a 농도는 염분도, BOD, DO, COD, pH, T-N와 양의 상관관계, 수온, 기온, $NO_3{^-}$-N과는 음의 상관관계가 있었다. 반면 명촌교의 경우 Chl a 농도는 8월 25일에 $55mg/m^3$로 최고값을 보였으며, Chl a 농도는 $NH_3$-N, T-N, $PO_4{^{3-}}$-P, T-P, 일반세균과 양의 상관관계를 나타내었다. 연구의 결과는 태화강 하류에서 조사 지점에 따른 수질의 변동폭이 매우 크며, 조류 발생의 양상도 태화교와 명촌교 사이에 차이가 있음을 보여준다.