• Title/Summary/Keyword: parameters study

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Parametric study for influential factors on unbonded tendon stress increase (비부착 긴장재의 응력 변화에 영향을 미치는 변수에 관한 고찰)

  • 이선화;문정호;임재형
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.651-656
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    • 2000
  • The strain compatibility analysis shows that the influential parameters of loading type, reinforcing ratio, and span-depth ratio affect on the tendon stress in unbonded prestresses concrete member significantly. However, existing test results did not comply exactly with the analytical results. In consequence, the present study was planned to examine the parameters in order to complete Moon/Lim's design equation. The test variables with 12 specimens were loading type, reinforcing ratio, and span-depth ratio. As results, the effect of influential parameters were examined throughly and Moon/Lim's design equation was proven to be accurate.

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Chest Radiographic Parameters of Mediastinal Hemorrhage in Patients with Traumatic Aortic Injury Patients (외상성 대동맥손상 환자에서 관찰한 종격동 출혈의 흉부방사선 소견)

  • Choi, Wook Jin;Im, Kyoung Soo;Lee, Jae Ho;Ahn, Shin;Kim, Won
    • Journal of Trauma and Injury
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    • v.18 no.1
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    • pp.17-25
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    • 2005
  • Background: Traumatic rupture of the aorta is a life-threatening injury that must be diagnosed as rapidly as possible and treated immediately. The chest X-ray is a valuable tool for screening traumatic rupture of the aorta in blunt chest trauma. And various chest radiologic parameters are being used as diagnostic tools for aortic injury. The purpose of this study is to identify chest radiographic parameters that may assist in the detection of traumatic rupture of the aorta and to compare these findings with those of other reports. Methods: This study involved 30 adult patients with traumatic rupture of the aorta seen at the emergency department of the Asan Medical Center from 1997 to 2004. The control subjects were 30 healthy patients with neither lung nor cardiovascular disease. We retrospectively assessed over 14 parameters on chest X-rays. Results: In 11 of the 14 parameters, there were significant differences between the study group and the control group. There was no significant difference in the M/C ratio (mediastinumto-chest width ratio) between the two groups, and neither the left nor the right paraspinal interface was statistically significant (p value>0.05). Our study indicates that new criteria for the MC ratio and for the paraspinal interfaces are needed for screening traumatic aorta injury. The other radiographic parameters for traumatic rupture of the aorta need to be further assessed through a prospective study.

The Reliability Analysis for Homogeneous Slope Stability Using Stochastic Finite Element Method (확율유한요소법을 이용한 균질 사면의 신뢰성 해석)

  • 조래청;도덕현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.38 no.5
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    • pp.125-139
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    • 1996
  • This study was performed to provide the design method for soil structure which guarantees proper safety with uncertainty of soil parameters. For this purpose, the effect of uncertainty of soil parameters for slope stability was analyzed by Bishop's simplified method and Monte Carlo simulation(MC). And reliability analysis program, RESFEM, was developed by combining elastic theory, MC, FEM, SFEM, and reliability, which can consider uncertainty of soil parameters. For factor of safety(FS) 1.0 and 1.2 by Bishop's simplified method, the probability of failure(Pf) was analyzed with varying coefficient of variation(c.o.v.) of soil parameters. The Pf increased as c.o.v. of soil parameters increased. This implies that FS is not the absolute index of slope safety, and even if FS is same, it has different Pf according to c.o.v. of soil parameters. The RESFEM was able to express the Pf at each element in slope quantitatively according to uncertainty of soil parameters. The variation of Pf with uncertainty of soil parameters was analyzed by RESFEM, and it was shown that the Pf increased as the c.o.v. of soil parameters increased.

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Relation between Obesity Pattern Identification and Metabolic Parameters in Overweight and Obese Women (과체중 및 비만 여성에서 한방비만변증에 따른 체성분 및 대사관련 지표의 상관성)

  • Song, Miyoung;Kim, Hojun;Lee, Myeong-Jong
    • Journal of Korean Medicine for Obesity Research
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    • v.14 no.1
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    • pp.24-28
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    • 2014
  • Objectives: We conducted this study to analysis obesity pattern and obesity related blood parameters. Methods: A total of 64 overweight and obese (body mass index [BMI] ${\geq}23cm/kg^2$) women who had no other disease was recruited. Body composition and obesity related blood parameters were measured. Also subjects were given and filled out the Obesity pattern identification questionnaire. We analyzed the differences of body composition and blood parameters and measured correlations of BMI and blood parameters in each obesity pattern. Results: The distribution of obesity pattern was liver depression (35.6%), food accumulation (47.5%) and deficiency (pi and yang deficiency, 22.0%), in order. There were no significant differences age, body composition and obesity related blood parameters between obesity patterns. BMI and obesity related blood parameters, however, showed significant correlations depending on obesity patterns. Conclusions: We concluded that correlations between BMI and obesity related blood parameters were differed depending on obesity patterns.

Correlation Analysis for deriving Control Parameters in Vertical Shafts by Design of Experiments (실험계획법에 의한 수직샤프트 제어인자 도출을 위한 상관관계 분석)

  • Han, Hwa-Taik;Shin, Chul-Yong;Baek, Chang-In
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.895-900
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    • 2008
  • It is the objective of the present study to conduct correlation analysis for deriving control parameters in vertical shafts using the results obtain by the design of experiments in the preceding research. The control parameters are categorized into objective parameters, derived parameters, condition parameters, operation parameters, and sensing parameters. The maximum pressure in the shaft should be sufficiently small in order to maintain exhaust hood performance. The pressure variations between floors should also be minimized in order to maintain uniform exhaust performance between floors and to save energy for excessive pressure drop in the shaft. The standard deviation based on -4Pa is proposed as an objective parameter to control pressure in shafts. The correlation equation has been obtained between the standard deviation and the sensing parameters of outdoor temperature and the pressure at the top of the shaft.

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Determination of Dynamic Parameters of Continuous Beam Using Morlet Wavelet (Morlet웨이블렛을 이용한 연속보의 동적 파라메터 추정)

  • 박종열;박형기;김규학
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.143-150
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    • 2002
  • This paper presents the application of continuous wavelet transform for determination of dynamic parameters of continuous beam subjected to moving load. Morlet wavelet is used as mother wavelet in wavelet transform. Dynamic parameters are estimated from the magnitudes and arguments of the wavelet coefficients obtained by wavelet transforming the response time histories of joints on the beam. This study shows that the estimated parameters such as natural frequencies, dmping ratios and mode shapes are to be well-compared with those of the finite element analysis.

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A Study on Design Parameters to Improve Load Capacity of Spiral Grooved Thrust Bearing (스파이럴 그루브 스러스트 베어링의 부하용량 향상을 위한 설계 변수에 대한 연구)

  • 강지훈;김경웅
    • Tribology and Lubricants
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    • v.18 no.3
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    • pp.181-186
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    • 2002
  • A numerical analysis is undertaken to show the influence of bearing design parameters on the load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, and the seal ratio.

An Evaluatiou of Parameter Variations for a Linear Reservoir (TANK) Model with Watershed Characteristics (유역특성에 따른 탱크모형 매개변수의 변화)

  • 김현영;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.42-52
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    • 1986
  • This study involves the estimation of optimal ranges of parameters for a linear watershed model. A well-known TANK model was chosen and a linear combination of four tanks assumed. The model was used to simulate daily streamflow for six watersheds of different sizes and by a trial-and-error approach a set of optimal parameters defined. The parameters were related to watershed sizes and land use conditions. Optimal parameters for ungaged conditions were defined from the relationships; daily streamflow simulated and compared to the observed date. The simulated results were in a general agreement with the data.

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Bayesian Test for the Difference of Exponential Guarantee Time Parameters

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • 한국데이터정보과학회:학술대회논문집
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    • 2004.04a
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    • pp.15-23
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    • 2004
  • When X and Y have independent two parameter exponential distributions, we develop a Bayesian testing procedures for the equality of two location parameters. Under the noninformative prior, we propose a Bayesian test procedures for the equality of two location parameters using fractional Bayes factor and intrinsic Bayes factor. Simulation study and some real data examples are provided.

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A Study on Signal Parameters Estimation via Nonlinear Minimization

  • Jeong, Jung-Sik
    • Journal of Navigation and Port Research
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    • v.28 no.4
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    • pp.305-309
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    • 2004
  • The problem for parameters estimation of the received signals impinging on array sensors has long been of great research Interest in a great variety of applications, such as radar, sonar, and land mobile communications systems. Conventional subspace-based algorithms, such as MUSIC and ESPRIT, require an extensive computation of inverse matrix and eigen-decomposition In this paper, we propose a new parameters estimation algorithm via nonlinear minimization, which is simplified computationally and estimates signal parameters simultaneously.