• Journal of the Korean Statistical Society
• /
• 제11권1호
• /
• pp.45-58
• /
• 1982

The problem of comparing k normal populations with a control (or a standard) in terms of the absolute values of their means is considered. Under the framework of indifference-zone formulation a single-state and a two-stage procedures for selecting the best are proposed, according to their commom vairances known or unknown respectively. The procedures guarantee that the probability of correct selection is not less than some preassigned lower limit. Selected tables necessary to implement the procedures are provided.

• 조명전기설비학회논문지
• /
• 제25권12호
• /
• pp.67-73
• /
• 2011

A method obtaining position data(x, y) of object accurately is proposed by using a pair of ultrasonic sensors composed of one transmitter and two receivers. And the driving system which controls the light of flat LED lamp locally using array of ultrasonic sensors (3 transmitters and 6 receivers) is developed. As a result, measured values of y are relatively reliable due to its small average of absolute errors of 1.03[cm]. The measured values of x have average error of 8.52[cm], and it is a large value. However, the average error is decreased by 0.65[cm] after applying algorithm for error correction. The experiments to control the light of flat LED lamp locally with algorithm for error correction are carried out. From the result, measured values of x with average error of 0.97[cm] are obtained and they are very good approximations of actual values.

• Computers and Concrete
• /
• 제9권2호
• /
• pp.153-169
• /
• 2012

The contribution of steel fibers on the 28-day compressive strength of high-performance steel fiber reinforced concrete was investigated, is presented. An extensive experimentation was carried out over water-cementitious materials (w/cm) ratios ranging from 0.25 to 0.40, with silica fume-cementitious materials ratios from 0.05 to 0.15, and fiber volume fractions ($V_f$= 0.0, 0.5, 1.0 and 1.5%) with the aspect ratios of 80 and 53. Based on the test results of 44 concrete mixes, mathematical model was developed using statistical methods to quantify the effect of fiber content on compressive strength of HPSFRC in terms of fiber reinforcing index. The expression, being developed with strength ratios and not with absolute values of strengths, is independent of specimen parameters and is applicable to wide range of w/cm ratios, and used in the mix design of steel fiber reinforced concrete. The estimated strengths are within ${\pm}3.2%$ of the actual values. The model was tested for the strength results of 14 mixes having fiber aspect ratio of 53. On examining the validity of the proposed model, there exists a good correlation between the predicted values and the experimental values of different researchers. Equation is also proposed for the size effect of the concrete specimens.

• Earthquakes and Structures
• /
• 제8권5호
• /
• pp.957-976
• /
• 2015

Recently, two energy-based response parameters, i.e., the absolute and the relative elastic input energy equivalent velocity, have been receiving a lot of research attention. Several studies, in fact, have demonstrated the potential of these intensity measures in the prediction of the seismic structural response. Although some ground motion prediction equations have been developed for these parameters, they only provide marginal distributions without information about the joint occurrence of the spectral values at different periods. In order to build new prediction models for the two equivalent velocities, a large set of ground motion records is used to calculate the correlation coefficients between the response spectral values corresponding to different periods and components of the ground motion. Then, functional forms adopted in models from the literature are calibrated to fit the obtained data. A new functional form is proposed to improve the predictions of the considered models from the literature. The components of the ground motion considered in this study are the two horizontal ones only. Potential uses of the proposed equations in addition to the prediction of the correlation coefficients of the equivalent velocity spectral values are shown, such as the prediction of derived intensity measures and the development of conditional mean spectra.

• Steel and Composite Structures
• /
• 제23권6호
• /
• pp.715-726
• /
• 2017

The paper presents a numerical analysis of a steel-soil composite (SSC) culvert in the scope of static (dead and live) loads. The Abaqus program based on the finite element method (FEM) was used for calculations. Maximum displacements were obtained in the shell crown, and the largest stresses in the haunches. Calculation results were compared with the experimental ones and previous calculations obtained from the Autodesk Robot Structural Analysis (ARSA) program. The shapes of calculated displacements and stresses are similar to those obtained with the experiment, but the absolute values were generally higher than measured ones. The relative differences of calculated and measured values were in the range of 5-23% for displacements, and 15-42% for stresses. Developed calculation model of the SSC culvert in the Abaqus program allows obtaining reasonable values of internal forces in the culvert. Using both calculation programs, the relative differences for displacements were in the range of 15-39%, and 17-44% for stresses in favour of the Abaqus program. Three design methods (Sundquist-Pettersson, Duncan and CHBDC) were used to calculate the axial thrusts and bending moments. Obtained values were compared with test results. Generally, the design methods have conservative assumptions, especially in the live loads distribution, safety factors and consideration the interaction between soil and steel structure.

• Coupled systems mechanics
• /
• 제8권3호
• /
• pp.199-218
• /
• 2019

This paper studies the forced vibration of the hydro-elastic system consisting of the anisotropic (orthotropic) plate, compressible viscous fluid and rigid wall within the scope of the exact equations and relations of elastodynamics for anisotropic bodies for describing of the plate motion, and with utilizing the linearized exact Navier-Stokes equations for describing of the fluid flow. For solution of the corresponding boundary value problem it is employed time-harmonic presentation of the sought values with respect to time and the Fourier transform with respect to the space coordinate on the coordinate axis directed along the plate length. Numerical results on the pressure acting on the interface plane between the plate and fluid are presented and discussed. The main aim in this discussion is focused on the study of the influence of the plate material anisotropy on the frequency response of the mentioned pressure. In particular, it is established that under fixed values of the shear modulus of the plate material a decrease in the values of the modulus of elasticity of the plate material in the direction of plate length causes to increase of the absolute values of the interface pressure. The numerical results are presented not only for the viscous fluid case but also for the inviscid fluid case.

• Computers and Concrete
• /
• 제27권3호
• /
• pp.225-239
• /
• 2021

Carbon fiber reinforced polymer (CFRP) has extensive use in strengthening reinforced concrete structures due to its high strength and elastic modulus, low weight, fast and easy application, and excellent durability performance. Many studies have been carried out to determine the performance of the CFRP confined concrete cylinder. Although studies about the prediction of confined compressive strength using ANN are in the literature, the insufficiency of the studies to predict the strain of confined concrete cylinder using ANN, which is the most appropriate analysis method for nonlinear and complex problems, draws attention. Therefore, to predict both strengths and also strain values, two different ANNs were created using an extensive experimental database. The strength and strain networks were evaluated with the statistical parameters of correlation coefficients (R2), root mean square error (RMSE), and mean absolute error (MAE). The estimated values were found to be close to the experimental results. Mathematical equations to predict the strength and strain values were derived using networks prepared for convenience in engineering applications. The sensitivity analysis of mathematical models was performed by considering the inputs with the highest importance factors. Considering the limit values obtained from the sensitivity analysis of the parameters, the performances of the proposed models were evaluated by using the test data determined from the experimental database. Model performances were evaluated comparatively with other analytical models most commonly used in the literature, and it was found that the closest results to experimental data were obtained from the proposed strength and strain models.

• 대순사상논총
• /
• 제24_1권
• /
• pp.255-289
• /
• 2014

This study's aim is to identify modern and post-modern values and transnationalism embodied in Daesoon Thought and to seek for the new value to overcome irrationality of modern values in this society we live in. Several previous studies discussed about these issues, but most of them studied them on the basis of Korean new religions or Jeungsangyo, or in sociological theory perspective. Therefore, this study focused on Daesoon Thought encompassing ideological perspective as well as historical perspective of Daesoonjinrihoe. As for nationalism, while Eastern learning(Dong-Hak) is prone to ethnocentricity, Daesoon Thought shows trans-ethnic perspective. As for historical perspectivel, Mugeuikdo, a precursor to Daesoonjinrihoe showed non-relationship with any politics as contrasted with other new korean religious movement at that time. As for aspects of modern values, 3 perspectives (political system, social system, abolition of premodern values) were discussed. As for political system perspective, while Eastern learning advocates democratic modernity but accepted monarchy, Jeungsan denied monarchy. And While western political philosophy advocated rationality-based absolute person, Daesoon Thought proposes ideal human who can have political power and do religious indoctrination all together. As for social system perspective, while western humanism is based on all of he people's equity in front of God, Eastern learning on humans are Heaven (人乃天), Daesoon Thought is based on Injon thought(人尊思想) which encompasses spiritual world, human world and all of the universe. Daesoon Thought also proposes abolition of discrimination by gender, social position. As for abolition of premodern values, Daesoon Thought critics pre-modern formalism and advocate acceptance of other nations' culture, pragmatism, and humanism. As presented above, Daesoon Thought has not only modern values but also aspects of post-modernity and transnationalism. In the future, further studies are needed which tackle these issues and search for new values of Daesoon Thought which can overcome limitation of modern values.

• 패션비즈니스
• /
• 제12권2호
• /
• pp.87-99
• /
• 2008

This study aims to classify lower trunk body types of Chinese men in their middle age (30s and 40s) and suggest the standard for them to design slacks pattern. Mollison's relation deviations were used to analyze the direct measurement items in this research compared to those of Size Korea 2004. Though Korean middle-aged men were higher in most items than Chinese counterparts, all items except mid-thigh circumference and side hip length were merely within the range of ${\pm}1\sigma$. According to the results of size classification by absolute values, factor analysis extracted to 2 factors(horizontal size of lower body and vertical size of lower body), and cluster analysis brought about 3 types(type1: tall and thin trunk (36.9%), type 2 : normal height and thick trunk(45.5%), and type 3 : short and normal trunk(17.6%) with some significant differences among them. Also, the results of shape classification by index values, they were extracted 4 factors (waist-hip flatness, waist-hip cross section, vertical waist-groin and hip-surface length) by factor analysis and revealed 3 types(type 1: different waist-hip width, thick, long waist, long upper hip, and short hip-surface length(27.8%), type 2 : different waist-hip width, flat, short upper hip, high hip and groin, and average hip-surface length(29.4%), and type 3: small waist-hip width, thick, average upper hip, and short hip-surface length (42.8%)) with significant differences among them by cluster analysis. The results of standard body types by shape-size combination, 19subjects(10.16%) under these values are regarded as standard body types. Significance was not seen in all items in the t-test results between the total group and the standard group. The latter had lower variation coefficients and smaller individual differences than the former. However, in-depth research is required for generalization since this research is limited to a small number of subjects in Ningbo of Zhejiang.

• 한국환경과학회지
• /
• 제8권2호
• /
• pp.151-154
• /
• 1999

To verify the accuracy of the numerical experiment of Part I, measurements at the matured rice canopy located around Junam reservoir were performed at August 14, 1995. According to the measured data, the foliage temperature recorded the highest value, and the ground temperature was the lowest around noon, and these results coincided with those of the numerical experiment using the combined model of Part I. From the estimation using measured data, the maximum value of the latent heat flux was 380$Wm^2$, the highest value among energy balance terms, and the energy redistribution ratio of the latent heat flux was averaged as 0.5, the highest values among redistribution ratios. These results are the same as those of the numerical experiment in tendency, but they reveals a little lower in the absolute values than those from the numerical experiment.