• Communications for Statistical Applications and Methods
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• v.27 no.5
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• pp.523-533
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• 2020

This paper suggests three available methods for finding nonnegative estimates of variance components of the random effects in mixed models. The three proposed methods based on the concepts of projections are called projection method I, II, and III. Each method derives sums of squares uniquely based on its own method of projections. All the sums of squares in quadratic forms are calculated as the squared lengths of projections of an observation vector; therefore, there is discussion on the decomposition of the observation vector into the sum of orthogonal projections for establishing a projection model. The projection model in matrix form is constructed by ascertaining the orthogonal projections defined on vector subspaces. Nonnegative estimates are then obtained by the projection model where all the coefficient matrices of the effects in the model are orthogonal to each other. Each method provides its own system of linear equations in a different way for the estimation of variance components; however, the estimates are given as the same regardless of the methods, whichever is used. Hartley's synthesis is used as a method for finding the coefficients of variance components.

• Wind and Structures
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• v.36 no.3
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• pp.149-160
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• 2023

Lightness and flexibility of membrane roofs make them very sensitive to any external load. One of the most important parameters that controls their behavior, especially under wind load is the sag/span ratio of edge cables. Based on the value of the pretension force in the edge cables and the horizontal projection of the actual area covered by the membrane, an optimized design range of cable sag/span ratios has been determined through carrying on several membrane form-finding analyses. Fully coupled fluid structure dynamic analyses of these membrane roofs are performed under wind load with several conditions using the CFD method. Through investigating the numerical results of these analyses, the behavior of membrane roofs with cables sag/span ratios selected from the previously determined optimized design range has been evaluated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.4
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• pp.379-386
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• 1992

In this paper a direction finding method which can which can estimate the direction angles of source signals impinging on the sensor array in which sensor noises are correlated is studied. This method performs the estimation of source direction angles form sensors, regardless of sensor noise correlation, by eliminating the sensor noise correlation coefficient which can be accurately estimated. Finally, this paper shows, through the computer simulation, that the proposed, method is extremely useful and superior when there exists the noise correlation between sensors, .

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1114-1117
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• 1993

The paper presents an effective method for finding the propagation structure of the real origin of a system malfunction. It uses a combined system model consisting of Structural Model (SM) in the form of Fuzzy Directed Graph and Behavior Model (BM) as a set of Fuzzy Relational Equations $A\;{\circ}\;R\;=\;B$. Here a specially proposed fuzzy inference technique is checked and investigated. Finally a test example for fault diagnosis of an industrial system is given and analyzed.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.158-161
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• 1995

A new laser diode range-finding speedometer is proposed, which is modulated by a pair of positive and negative triangular pulse current superimposed on a dc current. Since a target velocity is directly obtained form a pure Doppler beat frequency measured during the non-modulation period, the new sensor is free from the difficulties due to the critical velocity encountered in the previous sensor. Furthermore, the different amplitude of the two triangular pluses are so adjusted that the measurable range using only one laser head is greatly expanded to 10cm through 150cm, which is about two times that of the previous sensor. The measurement accuracy for velocity of .+-.6mm/s through .+-.20mm/s and for range is about 1%, and 2%, respectively. Because the new sensor can be operated automatically using a microcomputer, it will be useful for application of a 3-D range image measurement of a slowly moving object.

• Journal of Industrial Technology
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• v.18
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• pp.181-186
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• 1998

The flatness is the most important nature for the surface table. For finding such a flatness, the surface is surveyed along a number of straight lines parallel to the edges of table, which form a grid. Next, the variations in height of the grid points are measured relative to a datum point. If the number of such points is increased. It is not necessarily to use many grid points for finding the original flatness of a measured surface table. So, it is necessary to find the rational quantity of such grid points. It is found that about 220 points per $1m^2$ of surface table for measurement is the rational quantity with less than about 15% error of the original flatness.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.169-171
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• 2006

Nowadays, inverter welding is risen in spot welding, because can secure productivity. This study made changed output wave form of inverter welding equipment by several forms and measured electric current that pass to the second of transformer for welding. Purpose of study is finding electric current of most suitable form. Also, studied applies PID control in electric current control of inverter resistance weld device and heightens electric current precision.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.21-28
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• 1993

Occupational Safety & Health Code requires to calculate Design Load and stress for the approval within thirty working days prior to initiating each construction site work This study is to develop an easy and useful program that each safety manager. Controller or engineers are able to make output for the above mentioned form structure analyses without knowledge or engineering background of it. Therefore. three, randomly selected. different major student and engineers verified if they could make output. really without the engineering background. And then some deficiencies are corrected after finding those from the program operation.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.166-173
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• 1997

The present problem of this country building market in the face of 3D, in addition to a rise in construction cost, materials problems and opening a building market to foreign countries, is finding the efficient ways of overcoming these problems. So the efficacy of form work in technical improvement becomes important through scientific methods of the design and construction as advancement in th study of strength for Permanent form mortar is possible. According to the increment of polymer-cement ration, the degree of bending strength and compressive strength and impact strength increases. The optimum volume content of glass fiber seemed to be about 2.5% considering the distribution of glass fiber, workability and economy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5356-5363
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• 2012

The aim of this study was to validate the Korean Version of the Empathy Quotient-Short form(EQ-Short-K) in a sample of Korean nursing students. A total 528 students(494 female, 34 male) were studied by 2 groups. To provide a validity of the Empathy Quotient-Short form in Korean sample, exploratory factor analysis, reliability test and Pearson correlation coefficient were conducted. In study 1 (N=298), the finding of factor analysis confirmed that 11 of the 22 EQ-Short items were presented as a single-factor structure. The reliability estimate of the EQ-Short-K was high(.88). In terms of criterion validity, the EQ-short-K correlated positively with Interpersonal Reactivity Index(IRI)(r=.279, p<.000). In study 2 (N=230), the finding identified that the EQ-Short-K correlated positively with Interpersonal Competence Questionnaire(ICQ)(r=.351, p<.000). It suggested that the EQ-Short-K had satisfactory internal consistency and validity, thereby the EQ-Short-K can be used as a meaningful measure for empathy among Korean nursing domain.