• Steel and Composite Structures
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• 제42권2호
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• pp.257-264
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• 2022

The analysis of the progressive collapse resistance of structures is a well-known issue among structural engineers. Large-span reticulated dome structures are commonly utilized in large public buildings, necessitating research into their progressive collapse resistance to assure user safety. The most significant part of improving the structural resilience of reticulated domes is to evaluate their key elements. Based on a stiffness-based evaluation approach, this work offers a calculating procedure for element importance coefficient. For both original and damaged structures, evaluations are carried out using the global stiffness matrix and the determinant. The Kiewitt, Schwedler, and Sunflower reticulated domes are investigated to explore the distribution characteristic of element importance coefficients in the single-layer dome structures. Moreover, the influences of the load levels, load distributions, geometric parameters and topological features are also discussed. The results can be regarded as the initial concept design reference for single-layer reticulated domes.

• Journal of the Korean Wood Science and Technology
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• 제36권5호
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• pp.33-41
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• 2008

This study was aimed to develop the knot quantification method to predict bending strength, using x-ray scanner. The bending strength prediction model was proposed in this paper. The model was based on Knot Depth Ratio (KDR) and closely-spaced knot was taken into account. The previous paper reported that KDR is the ratio of the knot and transit zone to the lumber thickness. Even though KDR involves transit zone, it was verified that the ratio of the moment of inertia for knot to gross cross section ($I_k/I_g$) based on KDR was a good predictor for bending strength of lumber. To take closely-spaced knot into account, a projection method was also proposed. This projection method improved the predictive accuracy significantly. It showed coefficient of determinant of 0.65 and root mean square error (RMSE) of 9.17.

• Structural Engineering and Mechanics
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• 제46권2호
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• pp.269-294
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• 2013

This paper is concerned with the determination of exact buckling loads and vibration frequencies of variable thickness isotropic plates using well known finite difference technique. The plates are subjected to uni, biaxial compression and shear loadings and various combinations of boundary conditions are considered. The buckling load is found out as the in plane load that makes the determinant of the stiffness matrix equal to zero and the natural frequencies are found out by carrying out eigenvalue analysis of stiffness and mass matrices. New and exact results are given for many cases and the results are in close agreement with the published results. In this paper, like finite element method, finite difference method is applied in a very simple manner and the application of boundary conditions is also automatic.

• 대한수학회논문집
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• 제37권1호
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• pp.303-326
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• 2022

Our aim is to construct Hermite-type exponentially fitted interpolation formulas that use not only the pointwise values of an 𝜔-dependent function f but also the values of its first derivative at three unequally spaced nodes. The function f is of the form, f(x) = g₁(x) cos(𝜔x) + g₂(x) sin(𝜔x), x ∈ [a, b], where g₁ and g₂ are smooth enough to be well approximated by polynomials. To achieve such an aim, we first present Hermite-type exponentially fitted interpolation formulas I_N built on the foundation using N unequally spaced nodes. Then the coefficients of I_N are determined by solving a linear system, and some of the properties of these coefficients are obtained. When N is 2 or 3, some results are obtained with respect to the determinant of the coefficient matrix of the linear system which is associated with I_N. For N = 3, the errors for I_N are approached theoretically and they are compared numerically with the errors for other interpolation formulas.

• 동력기계공학회지
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• 제19권2호
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• pp.70-77
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• 2015

Nowadays, car manufacturers applied many high strength steels such AHSS or UHSS to car bodies for weight lightening. Therefore, a variety of applied steel sheet to car bodies increased and the needs of simulation to evaluate weldability also increased in order to reduce the cost and time. In this study, resistance spot welding simulations for DP 780 Steel with 1.0 and 1.4 mm thickness were conducted with respect to lobe curve. 2 regression models to estimate tensile shear strength were suggested and they were second order polynomial regression model and optimized second order regression model. The performance of these models was evaluated in terms of the coefficient of determinant and average error rate.

• 한국공간구조학회논문집
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• 제3권2호
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• pp.101-107
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• 2003

There exists a structural problem for link structures in the unstable state. The primary characteristics of this problem are in the existence of rigid body displacements without strain, and in the possibility of the introduction of prestressing to change an unstable state into a stable state. When we make local linearized incremental equations in order to obtain knowledge about these unstable structures, the determinant of the coefficient matrices is zero, so that we face a numerically unstable situation. This is similar to the situation in the stability problem. To avoid such a difficult situation, in this paper a simple and straightforward method was presented by means of the generalized inverse for the numerical analysis of stability problem.

• 지역사회간호학회지
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• 제9권1호
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• pp.30-39
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• 1998

The purpose of this study was to identify the factors influencing health promoting lifestyle of teachers and to provide the data for efficient health management of teachers. The subjects of this study were eight hundred nine teachers, who were chosen in Choong-Buk province. Survey Questionaires for data analysis were collected through visiting or mailing from September 1 to 30, 1997. The instruments used in this study were HPLP(Health Promoting Lifestyle Profile) by Walker (1987), Internal Health Locus of Control by Walston et al. (1978), Self Esteem by Rogenberg(1965), Importance of Health by Muhlenkamp (1985), Self Efficacy by Sherer & Maddux(1982), and Family Function by Olson & Schellenberg (1985). Data were analyzed by descriptive statistics, unpaired t-test, ANOVA, Pearsons correlation coefficient and stepwise multiple regression using SPSS/PC(v. 4.01) program. The results were as follows; 1. The mean of health promoting lifestyle was total 2.53 on the average, self-actualization 2.97, nutrition 2.90, interpers 52, stress management 2.33, exercise 1.91, and health responsibility 1.82 in order. The index of total health promoting lifestyle was significantly influenced by the factors including sex, age, religion, marital status, duration of work, teaching load, education level and number of family members. 2. The health promoting Lifestyle was significantly positive correlated with Self Efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Self Esteem. 3. Self Efficacy was the most influential determinant predicting health promoting lifestyle of teachers. Self efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Age explained 42% of the health promoting lifestyle. Based on the above findings, it is suggested to develop nursing intervention to improve Self Efficacy, Importance of Health, Family Function of teachers enhance health promoting lifestyle. Further studies are needed to confirm these findings and to determine factors which significantly influence health promoting lifestyle of teachers.

• 한국농공학회지
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• 제32권4호
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• pp.27-43
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• 1990

This study aimed at developing a generalized model on the estimation of the long - term run - off volume for practical purpose. During the research period of last 3 years( 1986-1988), 3 types of estimation model on the long - term run - off volume(Effective rainfall model, unit hydrograph model and barne's model for dry season) had been developed by the author. In this study, through regressional analysis between determinant factors (bi of effective rainfall model, ai of unit hydrograph model and Wi of barne's model) and catchment characteris- tics(catchment area, distance round the catchment area, massing degree coefficient, river - exte- nsion, river - slope, river - density, infiltration of Watershed) of 11 test case areas by multiple regressional method, a new methodology on the derivation of determinant factors from catchment characteristics in the watershed areas having no hydrological station was developed. Therefore, in the resulting step, estimation equations on run - off volume for practical purpose of which input facor is only rainfall were developed. In the next stage, the derived equations were applied on the Kang - and Namgye - river catchment areas for checking of their goodness. The test results were as follows ; 1. In Kang - river area, average relative estimation errors of 72 hydrographs and of continuous daily run - off volume for 245 days( 1/5/1982 - 31/12) were calculated as 6.09%, 9.58% respectively. 2. In Namgye - river area, average relative estimation errors of 65 hydrographs and of conti- nuous daily run - off volume for 2fl days(5/4/1980-31/12) were 5.68%, 10.5% respectively. In both cases, relative estimation error was averaged as 7.96%, and so, the methodology in this study might be hetter organized than Kaziyama's formula when comparing with the relative error of the latter, 24~54%. However, two case studies cannot be the base materials enough for the full generalization of the model. So, in the future studies, many test case studies of this model should he carries out in the various catchment areas for making its generalization.

• 농업과학연구
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• 제39권4호
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• pp.603-612
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• 2012

In this research, the feasibility of non-destructive measurement technique of pungency measurement was investigated for the red-pepper powders produced in different domestic areas in South Korea. The near-infrared absorption spectra in the range of 1100 nm~2300 nm was used to measure capsaicinoids content in red-pepper powders by using a NIR spectroscopy equipped with Acousto-optic tunable filters (AOTF). Fourth three different red-pepper powders from 14 different locations were collected and separated in three different particle size (below 0.425 mm, 0.425~0.71 mm, 0.71~1.4 mm) for the spectral measurements. The partial least square regression (PLSR) models to predict the capsaicinoids content depends on particle size were developed with the measured spectra. The determinant coefficients and standard errors of the developed models for the red-pepper powders of below 0.425 mm, 0.425~0.71 mm, and 0.71~1.4 mm were in the range of 0.859~0.887 and 12.90~12.99 mg/100 g, respectively. The PLS model with the pretreatment of Standard Normal Variate (SNV) for the red-pepper powders below 1.4 mm particle size showed the best performance with the determinant coefficient of 0.844 and the standard error of 14.63 mg/100 g.

• Kyungpook Mathematical Journal
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• 제56권3호
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• pp.899-910
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• 2016

It is known that a semi-cubically hyponormal weighted shift need not satisfy the flatness property, in which equality of two weights forces all or almost all weights to be equal. So it is a natural question to describe all semi-cubically hyponormal weighted shifts $W_{\alpha}$ with first two weights equal. Let ${\alpha}$ : 1, 1, ${\sqrt{x}}$(${\sqrt{u}}$, ${\sqrt{v}}$, ${\sqrt{w}}$)^ be a backward 3-step extension of a recursively generated weight sequence with 1 < x < u < v < w and let $W_{\alpha}$ be the associated weighted shift. In this paper we characterize completely the semi-cubical hyponormal $W_{\alpha}$ satisfying the additional assumption of the positive determinant coefficient property, which result is parallel to results for quadratic hyponormality.