• Steel and Composite Structures
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• 제38권4호
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• pp.447-462
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• 2021

In this work, we consider a problem in the context of thermoelectric materials with memory-dependent derivative for a half space which is assumed to have variable thermal conductivity depending on the temperature. The Lamé's modulii of the half space material is taken as a function of the vertical distance from the surface of the medium. The surface is traction free and subjected to a time dependent thermal shock. The problem was solved by using the Laplace transform method together with the perturbation technique. The obtained results are discussed and compared with the solution when Lamé's modulii are constants. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions. Affectability investigation is performed to explore the thermal impacts of a kernel function and a time-delay parameter that are characteristic of memory dependent derivative heat transfer in the behavior of tissue temperature. The correlations are made with the results obtained in the case of the absence of memory-dependent derivative parameters.

• 품질경영학회지
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• 제29권3호
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• pp.124-137
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• 2001

In general, it is very efficient and effective to use screening variables that are correlated with the performance variable in case that measuring the performance variable is impossible (destructive) or expensive. The general methodology for searching surrogate variables is regression analysis. This paper considers the inspection problem in CRT (Cathode Ray Tube) production line, in which the performance variable (dependent variable) is binary type and screening variables are continuous. The general regression with dummy variable, discriminant analysis and binary logistic regression are considered. The cost model is also formulated to determine economically inspection procedure with screening variables.

• 대한수학회보
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• 제53권6호
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• pp.1597-1612
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• 2016

There are fruitful results on degenerate parabolic-hyperbolic equations recently following the idea of $Kru{\check{z}}kov^{\prime}s$ doubling variables device. This paper is devoted to the well-posedness of nonhomogeneous boundary problem for degenerate parabolic-hyperbolic equations with spatially dependent second order operator, which has not caused much attention. The novelty is that we use the boundary flux triple instead of boundary layer to treat this problem.

• Steel and Composite Structures
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• 재36권6호
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• pp.617-629
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• 2020

The purpose of this paper is to depict the effect of rotation and initial stress on a magneto-thermoelastic medium with diffusion. The problem discussed within memory-dependent derivative in the context of the three-phase-lag model (3PHL), Green-Naghdi theory of type III (G-N III) and Lord and Shulman theory (L-S). Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique. Numerical results for the field quantities given in the physical domain and illustrated graphically in the absence and presence of a magnetic field, initial stress as well as the rotation. The differences in variable thermal conductivity are also presented at different parameter of thermal conductivity. The numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. Some special cases are also deduced from the present investigation.

• East Asian mathematical journal
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• 제32권2호
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• pp.253-289
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• 2016

This study attempted to figure out new teaching method of mathematics teaching-learning by applying Polya's 4-level strategy to mild disability students at the H Special-education high school where the research works for. In particular, epilogue and suggestion, which Polya stressed were selected and reconstructed for mild disability students. Prior test and post test were carried by putting the Polya's problem solving strategy as independent variable, and problem solving ability as dependent variable. As a result, by continual use of Polya's program in mathematics teaching course, it suggested necessary strategies to solve mathematics problems for mild disability students and was proven that Polya's heuristic training was of help to improve problem solving in mathematics.

• 품질경영학회지
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• 제32권3호
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• pp.109-125
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• 2004

This paper deals with an optimal process control problem in production of hull structural steel plate with high defective rate. The main quality characteristic(dependent variable) is the internal quality(defect) of plates and is dependent on process parameters(independent variables). The dependent variable(quality characteristics) has three categorical ordinal data and there are 35 independent variables(29 continuous variables and 6 categorical variables). In this paper, we determine the main factors and to develop the mathematical model between internal quality predicted probabilities and the main factors. Secondly, we find out the optimal process condition of main factors through analysis of variance(ANOVA) using simulation. We consider three models to obtain the main factors and the optimal process condition: linear, quadratic, error models.

• 경영과정보연구
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• 제29권4호
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• pp.109-121
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• 2010

본 연구는 전형적인 차량경로 문제에서 각 노드간의 이동 시간이 일정하지 않은 특수한 경우의 상황에 대한 해법 절차를 제공한다. 본 연구는 상황에 따라 변화하는 이동시간을 갖는 외판원 문제의 특별한 경우인 '한 노드까지 도달한 경로가 다음 노드로 이동하는 데 걸리는 시간에 영향을 주는 외판원 문제'(경로의존 이동비용을 갖는 외판원 문제(RDTSP: Route Dependent Travelling Salesman Problem))의 해법을 제시한다. RDTSP 문제의 해결을 위해 먼저 문제 상황을 묘사하는 정수 계획 모형을 개발하였다. 본 연구에서 제시한 정수계획 모형에서는, 모든 가능한 경로에 대하여 각각의 경로를 하나의 변수로 정의하고 이 변수들 중에서 하나를 선택하는 형태로 개발되었다. 이 모형에서는 변수에 해당하는 가능한 경로의 수가 노드수에 지수적(exponentially)으로 증가하기 때문에, 처음부터 모든 변수를 문제에 포함시켜 풀 수 없게 된다. 그러나, 개발된 정수계획 모형의 변수를 실수로 완하시킨 선형완화(LP relaxation) 문제에 대해서는 열 생성(column generation) 기법을 통해 그 해를 구할 수 있다. 또한 본 연구의 결과가 PCB 조립 공정의 작업시간 최적화 문제에 어떻게 적용될 수 있는가를 제시한다.

• Structural Engineering and Mechanics
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• 제4권1호
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• pp.49-59
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• 1996

This paper considers large deflection problem of a simply supported beam with variable are length subjected to a point load. The beam has one of its ends hinged and at a fixed distance from this end propped by a frictionless support over which the beam can slide freely. This highly nonlinear flexural problem is solved by elliptic-integral method and shooting-optimization technique, thereby providing independent checks on the new solutions. Because the beam can slide freely over the frictionless support, there is a maximum or critical load which the beam can carry and it is dependent on the position of the load. Interestingly, two possible equilibrium configurations can be obtained for a given load magnitude which is less than the critical value. The maximum arc-length was found to be equal to about 2.19 times the fixed distance between the supports and this value is independent of the load position.

• 아태비즈니스연구
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• 제11권2호
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• pp.27-43
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• 2020

Purpose - This study explores the impact of the real estate industry on related industries for the perspective of Chinese steel companies. Design/methodology/approach - The impact of housing prices on the 41 listed steel companies' performance was analyzed by using the panel data model. We used two kinds of housing price indexes that are set in the panel data models to estimate the range of the real estate market, driving the performance growth of steel listed companies. Moreover, the net profit of steel companies is used as the dependent variable. To test the stability of the model, ROA used as a dependent variable for the robustness test. Also, to avoid the time trend of housing prices, this paper selects the growth rate of housing prices as the primary research variable. After Fisher-type testings, there is no unit root problem in both independent and dependent variables. Findings - The results indicated that the rise in the housing price has a positive influence on the steel company performance. When the housing price increases by 1%, the net profit of steel enterprises will increase by 5 to 20 million yuan. Research implications or Originality - In this paper, empirical data at the micro-level and panel model are used to quantify China's real estate industry's driving effect on the iron and steel industry, providing evidence from the microdata level. It helps us to understand further the status and role of China's real estate industry in the economic structure.

• Geomechanics and Engineering
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• 제28권4호
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• pp.347-358
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• 2022

The main concern of this article is to discuss the problem of a two-temperature fiber-reinforced micropolar thermoelastic medium with voids under the effect rotation, mechanical force in the context four different theories with memory-dependent derivative (MDD) and variable thermal conductivity. The three-phase-lag model (3PHL), dual-phase-lag model (DPL), Green-Naghdi theory (G-N II, G-N III), coupled theory, and the Lord-Shulman theory (L-S) are employed to solve the present problem. Analytical expressions of the physical quantities are obtained by using Laplace-Fourier transforms technique. Numerical results are shown graphically and the results obtained are analyzed. The most significant points are highlighted.