• Title/Summary/Keyword: correlated parameters

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Modal analysis of a vehicle cabin model having high decoupling tendency (다종의 가진방법을 이용한 비연성 경향을 가진 차실모형의 모우드 해석)

  • 김시조;조동우;한상욱
    • Journal of the korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.25-37
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    • 1992
  • Interior noise in a car is known to have an important influence on product acceptability. This noise is closely correlated with structural-acoustic vibration. When considering noise problem, the structural-acoustic relation of a vehicle cabin model needs to be identified. However, it is very difficult to get the modal parameters of this kind of cabin structure composed of thin plates: because it not only can be excited by the acoustic vibration of cavity, but also tends to have decoupling effects of one plate from another. In order to obtain modal parameters more precisely, various excitation techniques, i.e. impact, pure random, burst random, and swept sine testing are applied for the first step. In the case of the cabin model, impact and swept sine testing show good results. Next, the determination of the excitation point by trial- and-error and the accurate measurements of FRF's are performed with these methods. The modal parameter extraction is carried out for the final step. This paper proposes a new approach to find the modal parameters more reliably in the case of high decoupling effects. That is, the convergence of MIF and MCF in each panel, which provide some criteria for the validity of the obtained modal parameters, is observed. And from those results, the pretty accurate modal parameters can be determined. A comparative assessment between the modal testing and the FEM is also performed.

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A STUDY ON THE EVOLUTION OF GLOBULAR CLUSTERS

  • Lee, See-Woo
    • Journal of The Korean Astronomical Society
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    • v.11 no.1
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    • pp.1-30
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    • 1978
  • The four dimensional classification of globular dusters with the parameters, Z, Y, age and HB type is presented defining two new parameters. $(B-V)_{1/2}\;and\;S_{3/2}$ which are shown to be tightly correlated with Kinman's spectral types and the helium abundances obtained from the R-method, respectively. The Z- and Y- abundances are derived from $(B-V)_{1/2}\;and\;S_{3/2}$, respectively, and the latter parameters determine the age class of clusters with help of Dickens' HB type, which is a function of Z. Y and age. For the examined forty two globular clusters the computed range at Z and Y are $1.5{\times}10^{-4}{\leq}Z{\leq}4.5{\times}10^{-2}\;and\;0.23<Y{\leq}0.41$. The age difference between the oldest (HB type 1) and the youngest (HB type 7) clusters is roughly estimated to be $2-4{\times}10^9$ years. Using these four parameters the known anomalous C-M diagrams seem to be reasonably interpreted without taking into account some complicate parameters such as unusually overabundant heavy elements, mass loss and mass spread, etc. The four dimensional scheme strongly suggests the slow successive collapses of the proto-Galaxy rather than a single fast collapse, and by this slow collapse model the inversion of chemical abundance gradient in the Galaxy can be explained. It is also shown that the clump position along the RGB near the HB level removes down to the fainter magnitude as the Z(Y)- abundance increases (decreases).

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The Effect of Environmental Parameters on Frost Formation on a Horizontal Cylinder (수평 실린더에서의 서리 생성에 대한 환경 변수들의 영향)

  • Lee, Yun-Bin;Ryu, In-Sang;No, Seung-Tak
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.2
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    • pp.253-260
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    • 2002
  • It is known that frost formation on surfaces of the heat exchanger seriously affects the performance of the refrigeration system. Accordingly, defrosting should follow, and effective defrosting is possible only when both analytic tools and comprehensive experimental data on frost formation are assailable. An experimental investigation was undertaken to characterize the effect of environmental parameters on frost formation on a horizontal cylinder in cross uniform flow. Several experiments were carried out with various environmental parameters such as inlet air temperature, inlet air humidity, air velocity and cooling surface temperature. Frost thickness, mass, surface temperature and cylinder inner and outer temperature were measured at front and rear positions of the cylinder. Thickness, mass, density, and effective thermal conductivity of the frost layer were obtained from measured data and effects of environmental parameters on the frost formation were analyzed. Data from experiments were correlated using dimensionless variables.

A Study on Dietary Related Factors and Blood Parameters of Obese Children Residing in Samcheok (삼척지역 일부 중등도 이상 비만 아동의 식생활관련 요인과 혈액성상에 관한 연구)

  • Lee, Jae-Cheol;Kim, Mi-Hyeon
    • Journal of the Korean Dietetic Association
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    • v.11 no.2
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    • pp.190-204
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    • 2005
  • The purpose of this study was to investigate the dietary related factors and blood parameters of moderately or severely obese children residing in Samcheok. Anthropometric measurement, 24-hour recall for dietary intake, blood analysis and questionnaire response including nutritional knowledge, nutritional attitude, body image recognition and eating habits were conducted in 23 obese children(16 boys and 7 girls) and their mother. The mean age of subjects are 10.0 years. The average body weight, BMI, obesity index and percent body fat were 57.5㎏, 27.0㎏/$m^2$, 47.3 and 38.1% in boys and 51.0㎏, 24.8㎏/$m^2$, 40.3 and 43.9% in girls. The average nutritional attitude, the self-satisfaction and the nutritional knowledge scores in subjects were 29.9/40, 32.7/50 and 7.3/10, respectively. 34.8% of the subjects were unsatisfied with their body image, whereas, 81.8% of their mothers were unsatisfied with children’s body image. 60.9% of subjects had one or both obese parents. Average intake of energy were 90.6% of RDA in boys and 84.3% of RDA in girls. The ratio of energy from carbohydrate/protein/fat were 66/16/18 in boys and 66/17/17 in girls. The mean serum cholesterol concentration of the subjects was 191.8mg/dl and 78.3% of the subjects were above the normal serum cholesterol rage of children. In the results of correlation analysis, obesity index was negatively correlated with self and mother’s nutritional attitude scores. Body weight and BMI were positively correlated with vitamin C(p<0.05) and fruits(p<0.05) intakes. And there was a positive correlation between obesity index and BMI, and serum cholesterol(p<0.05).

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EFFECT OF LONG TERM SELECTION ON GENETIC PARAMETERS OF ECONOMIC TRAITS IN WHITE LEGHORN

  • Sharma, D.;Johari, D.C.;Kataria, M.C.;Singh, B.P.;Singh, D.P.;Hazary, R.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.4
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    • pp.455-459
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    • 1996
  • The genetic parameters for various economic traits were estimated in a White Leghorn population selected for part period egg production over 16 generations. In early part of selection, egg number had moderate to high heritability (0.26 to 0.51) while age at sexual maturity, egg weight and body weight at 20 and 40 weeks of age had high heritability (0.54 to 0.83). The sire component heritability for all the traits except 20 week body weight declined in later periods of selection. Sex linked gene effects for egg number and age at sexual maturity were more important in early periods of selection in comparison to the later periods, while maternal effects remained important for 20 week body weight in all the periods. Egg number was negatively correlated with egg weight ($r_{G(S)}=-0.36$), age at sexual maturity ($r_{G(S)}=-0.84$) and 40 week body weight ($r_{G(S)}=-0.84$), while it was positively correlated with 20 week body weight ($r_{G(S)}=-0.34$) in base generation. The genetic association between egg number and 40 week body weight changed not only in magnitude but also in direction in later periods. The genetic correlation of egg number with egg weight as well as with age at sexual maturity also decreased in magnitude in later periods of selection.

Scanning Electron Microscopic Studies on Leaf Surface Trichomes in Mulberry and Its Influence on Rearing Performance of Silkworm Bombyx mori L.

  • Kesavacharyulu, K.;Kumar, Vineet;Sarkar, A.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.8 no.1
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    • pp.33-41
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    • 2004
  • The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (>1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

Effects of Physical Parameters and Age on the Order of Entrance of Hynobius leechii to a Breeding Pond

  • Lee, Jung-Hyun;Park, Dae-Sik
    • Journal of Ecology and Environment
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    • v.31 no.3
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    • pp.183-191
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    • 2008
  • To determine the age structure of a Hynobius leechii breeding population and analyze relationships between the order of entrance to breeding ponds and physical parameters and age, we studied a wild population of the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Korea from March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of females ranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm, respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-vent length (SVL), head length, and body mass of males were all positively correlated with their age, but female age did not show a significant relationship with any physical parameter. The tail depth, body mass, and condition factors (SVL/body mass $\times$ 100) of both males and females were negatively related with the order of entrance to the breeding pond. The head width and SVL of males were also negatively correlated with the order of entrance, but the SVL of females was positively related with the order of entrance. These results suggest that physical parameters are more important determinants of breeding migration patterns than age. We discuss which of two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explain the order of entrance to breeding ponds for male and female H. leechii.

Clinical Significance of Preoperative Inflammatory Parameters in Gastric Cancer Patients

  • Lee, Deuk Young;Hong, Seong Woo;Chang, Yeo Goo;Lee, Woo Yong;Lee, Byungmo
    • Journal of Gastric Cancer
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    • v.13 no.2
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    • pp.111-116
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    • 2013
  • Purpose: Chronic inflammation induces cancer and cancer induces local tissue damage with systemic inflammation. Therefore, the aim of this study is to investigate the potential relationship between the severity of inflammation and prognosis in cancer patients. Materials and Methods: This study enrolled 220 patients from January 2002 to December 2006 who underwent gastric surgery. We evaluated the relationship between preoperative inflammatory parameters (erythrocyte sedimentation rate, neutrophil-to-lymphocyte ratio) and other clinicopathological factors. Survival outcomes were compared according to the extent of inflammation. Results: Significant elevation of erythrocyte sedimentation rate was related with old age, increased neutrophil-to-lymphocyte ratio, decreased hemoglobin, increased carcinoembryonic antigen, increased tumor size and advanced TNM stage. Neutrophil-to-lymphocyte ratio was significantly correlated with old age, increased erythrocyte sedimentation rate and advanced TNM stage. In the univariate analysis, elevated erythrocyte sedimentation rate and increased neutrophil-to-lymphocyte ratio had significantly poorer survival than those without elevation (all P<0.05). However, the multivariate analysis failed to prove erythrocyte sedimentation rate and neutrophil-tolymphocyte ratio as independent prognostic factors. Conclusions: The elevation of erythrocyte sedimentation rate and neutrophil-to-lymphocyte ratio were correlated with poor prognosis in the univariate analysis and there was a strong correlation between inflammatory parameters (erythrocyte sedimentation rate and neutrophil- to-lymphocyte ratio) and tumor progression. Thus, erythrocyte sedimentation rate and neutrophil-to-lymphocyte ratio are considered useful as follow-up factors.

Potency and plasma protein binding of drugs in vitro-a potentially misleading pair for predicting in vivo efficacious concentrations in humans

  • Yim, Dong-Seok
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.4
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    • pp.231-236
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    • 2019
  • In drug discovery or preclinical stages of development, potency parameters such as $IC_{50}$, $K_i$, or $K_d$ in vitro have been routinely used to predict the parameters of efficacious exposure (AUC, $C_{min}$, etc.) in humans. However, to our knowledge, the fundamental assumption that the potency in vitro is correlated with the efficacious concentration in vivo in humans has not been investigated extensively. Thus, the present review examined this assumption by comparing a wide range of published pharmacokinetic (PK) and potency data. If the drug potency in vitro and its in vivo effectiveness in humans are well correlated, the steady-state average unbound concentrations in humans [$C_{u_-ss.avg}=f_u{\cdot}F{\cdot}Dose/(CL{\cdot}{\tau})=f_u{\cdot}AUCss/{\tau}$] after treatment with approved dosage regimens should be higher than, or at least comparable to, the potency parameters assessed in vitro. We reviewed the ratios of $C_{u_-ss.avg}$/potency in vitro for a total of 54 drug entities (13 major therapeutic classes) using the dosage, PK, and in vitro potency reported in the published literature. For 54 drugs, the $C_{u_-ss.avg}$/in vitro potency ratios were < 1 for 38 (69%) and < 0.1 for 22 (34%) drugs. When the ratios were plotted against $f_u$ (unbound fraction), "ratio < 1" was predominant for drugs with high protein binding (90% of drugs with $f_u{\leq}5%$; i.e., 28 of 31 drugs). Thus, predicting the in vivo efficacious unbound concentrations in humans using only in vitro potency data and $f_u$ should be avoided, especially for molecules with high protein binding.

Development of Estimation Indices for Refractory Organic Matter in the Han-River Basin using Organic Matter Parameters and Spectroscopic Characteristics (일반 유기물 항목과 분광특성을 이용한 한강수계 내 난분해성 물질 지표 제시)

  • Lee, Bomi;Lee, Tae-Hwan;Hur, Jin
    • Journal of Korean Society on Water Environment
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    • v.27 no.5
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    • pp.625-633
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    • 2011
  • A long-term water quality monitoring in the Han River Basin reveals a consistent increasing trend for the concentration of refractory organic matter (R-OM) in major monitoring sites of the watershed. Because the determination of R-OM concentrations typically requires a long time of microbial incubation, it is essential to present the estimation indices for R-OM for an efficient watershed management. In this study, a number of surface water samples were classified into three groups, each of which were collected from Lake Paldang, rivers at rain and non-rain events, respectively. The corresponding R-OM concentrations were correlated with biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) concentrations as well as ultraviolet and fluorescence intensities of the filtered samples. Among the traditional organic matter parameters, TOC exhibited the highest correlation coefficient with the R-OM concentrations regardless of the types of the sample groups. The equations for conversing TOC into R-OM concentrations were finally suggested as $0.43{\times}TOC+1.12$, $0.44{\times}TOC+0.61$, $0.24{\times}TOC+1.28$ for river samples at rain and non-rain events, and lake samples, respectively. TOC-BOD(C), the values of the TOC concentrations subtracted by carbon-converted BOD concentrations, was a good index for estimating the absolute concentrations of R-OM. UV absorbance at 254 nm was well correlated with R-OM concentrations of river samples while fluorescence intensities at 350 nm showed an excellent relationship with R-OM concentration of the lake samples. Our results suggests that simple spectroscopic parameters could be applied for in-situ monitoring tool techniques in watersheds.