• 충청수학회지
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• 제13권2호
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• pp.61-70
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• 2001

Certain elliptic interacting system involving symbiotic is considered. The sufficient conditions for the existence of positive solutions of system is provided for four different types of interaction among three species by using the method of decomposing operator.

• Nonlinear Functional Analysis and Applications
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• 제27권4호
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• pp.855-867
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• 2022

This study finds three different solutions (3-Sol's) for the fourth order nonlinear discrete anisotropic equations (DAE) with real parameter. We use the variational method(VM) and 𝜙_p-Laplacian operator (𝜙_p-LO) to prove the main results. In the following paper, we take the parameters λ, 𝜇 such that λ > 0 and 𝜇 ≥ 0 into consideration.

• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.861-869
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• 2002

Radiative transfer by nongray gas mixtures with nonuniform concentration and temperature profiles is studied by using the statistical narrow-band model and the ray-tracing method with the sufficiently accurate T$\_$60/ quadrature set. Transmittances through the nonhomogeneous gas mixtures are calculated by using the Curtis-Godson approximation. Three different cases with different temperature and concentration profiles are considered profiles are considered to obtain benchmark solutions for the radiative transfer by nongray gas mixtures. The solutions obtained from this study are verified and found to be very well matched with the previous solutions for uniform gas mixtures. The results presented in this paper can be used as benchmark solutions in developing various solution methods for radiative transfer by nongray gas mixtures.

• 치과방사선
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• 제17권1호
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• pp.197-207
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• 1987

This study was undertaken to investigate the relationships between film and processing solution at different processing temperatures. Three kinds of periapical film were used for this study. They included EP-2l film, DF-58, and A film Each film was processed by automatic film processor with RD-Ⅲ X-dol 90, and A processing solutions at 68° 74° 80° 86° and 92°F. Film density was measured with the densitometer, and base plus fog density, film relative speed, film contrast, and subject contrast were evaluated. The following results were obtained; 1. As the processing temperature was increased, base plus density was increased. Inadequate base plus fog densities were obtained with three films in combination with three processing solutions at 92°F. 2. Lowest base plus fog densities were obtained with A film, followed in ascending order by EP-21, and DF-58 film in combination with A or RD-Ⅲ processing solutions. The sequence of base plus fog densities was in ascending order by EP-21, A, and DF-58 film in combination with X-dol 90 processing solution. 3. The sequence of film relative speed values was in ascending order of EP-21, A, and DF-58 film in combination with A and RD-Ⅲ processing solutions, respectively. 4. As the processing temperature was increased, film contrast values was increased. The sequence of film contrast values was in descending order solution. The sequence of film contrast values was in descending order of EP-2l, DF-58, and A film in combination with RD-Ⅲ, X-dol 90 processing solution at 80°F. 5. As the processing temperature was increased, subject contrast was increased. The sequence of subject contrast was in descending order of A, X-dol 90, and RD-Ⅲ processing solution in combination with three films at 80°F. The sequence of subject contrast was in descending order of EP-21, A, and DF-58 film in combination with A processing solution at different processing temperatures.

• 농업과학연구
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• 제49권3호
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• pp.643-653
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• 2022

This study investigated which nutrient solution is suitable for growth and secondary metabolite contents when three different vegetable plants are grown simultaneously in one hydroponic cultivation bed. Seeds of pak choi (Brassica compestris L. ssp chinsensis), red mustard (Brassica juncea L.), and arugula (Eruca sativa Mill.) were sown in the shape of a triangle in three places on rockwool cubes. The rockwool cubes were placed in semi deepflow technique (semi-DFT) hydroponic systems in a rooftop greenhouse after three weeks of growth as seedlings then cultivated with four different nutrient solutions, Korea Horticultural Experiment Station (KHE), Hoagland, Otsuka-A, and Yamazaki, at the rooftop greenhouse for two weeks. The leaf area of pak choi cultivated in Otsuka-A was the largest but SPAD values, leaf area, and fresh weight of arugula were highest with KHE treatment. The total glucosinolate (GSL) content of pak choi was 151.7% higher in KHE than in Hoagland, and there was no significant difference in Yamazaki and Otsuka-A treatments. The total GSL content of red mustard was 34.6 μmol·g^-1 in Hoagland, and it was 32.6% higher in Hoagland than in Yamazaki. Total GSL content of arugula was 57.5% higher in Yamazaki and Hoagland nutrients than in KHE and Otsuka-A nutrients solutions. The total GSL content of three plants grown with KHE was 40.7% higher than with Yamazaki, and the other nutrient solutions did not show significant differences. Therefore, KHE nutrient solution is considered suitable for nutrient solution composition for the cultivation of three different Brassicaceae crops in a single hydroponic cultivation system.

• Structural Engineering and Mechanics
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• 제43권2호
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• pp.239-251
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• 2012

The analysis of laterally loaded piles is generally carried out by idealizing the soil mass as Winkler springs, which is a crude approximation; however this approach gives reasonable results for many practical applications. For more precise analysis, the three- dimensional finite element analysis (FEA) is one of the best alternatives. The FEA uses the modulus of elasticity $E_s$ of soil, which can be determined in the laboratory by conducting suitable laboratory tests on undisturbed soil samples. Because of the different concepts and idealizations in these two approaches, the results are expected to vary significantly. In order to investigate this fact in detail, three-dimensional finite element analyses were carried out using different combinations of soil and pile characteristics. The FE results related to the pile deflections are compared with the closed-form solutions in which the modulus of subgrade reaction $k_s$ is evaluated using the well-known $k_s-E_s$ relationship. In view of the observed discrepancy between the FE results and the closed-form solutions, an improved relationship between the modulus of subgrade reaction and the elastic constants is proposed, so that the solutions from the closed-form equations and the FEA can be closer to each other.

• 대한수학회지
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• 제57권2호
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• pp.489-506
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• 2020

In this paper, we study the existence of infinitely many large energy solutions for the supercubic fractional Schrödinger-Poisson systems. We consider different superlinear growth assumptions on the non-linearity, starting from the well-know Ambrosetti-Rabinowitz type condition. We obtain three different existence results in this setting by using the Fountain Theorem, all these results extend some results for semelinear Schrödinger-Poisson systems to the nonlocal fractional setting.

• Earthquakes and Structures
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• 제8권3호
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• pp.511-539
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• 2015

The main objective of this study is to analytically investigate the effectiveness of different strengthening solutions in upgrading the seismic performance of existing reinforced concrete (RC) buildings in Nepal. For this, four building models with different structural configurations and detailing were considered. Three possible rehabilitation solutions were studied, namely: (a) RC shear wall, (b) steel bracing, and (c) RC jacketing for all of the studied buildings. A numerical analysis was conducted with adaptive pushover and dynamic time history analysis. Seismic performance enhancement of the studied buildings was evaluated in terms of demand capacity ratio of the RC elements, capacity curve, inter-storey drift, energy dissipation capacity and moment curvature demand of the structures. Finally, the seismic safety assessment was performed based on standard drift limits, showing that retrofitting solutions significantly improved the seismic performance of existing buildings in Nepal.

• 한국해안해양공학회지
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• 제18권3호
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• pp.225-240
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• 2006

판에 작용하는 등분포하중과 등변분포하중에 의한 휨 모멘트를 계산하기 위해 무차원 방정식에 대한 유한 차분법으로 제시하고 변장비와 격자수에 따른 수치해의 수렴을 분석하였다. 유한 차분법의 수치해는 격자점을 최대 11,520개까지 사용하여 해를 구하였고 변장비에 따른 최적 격자수를 제시하였다. 본 수치해는 Levy형 해석 해와 달리 자유단의 모멘트 경계조건을 만족하며 자유단과 고정단의 교점부근에서는 특이한 모멘트 분포를 보인다. 등분포하중과 등변분포하중에 의한 Levy형 해석해의 무차원 휨 모멘트 값과 본 결과를 비교하였으며 특이한 분포를 보이는 자유단과 그 부근을 제외하면 두 값은 동일한 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제37권4호
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• pp.415-425
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• 2011

In this study, the homotopy perturbation method (HPM) is applied to free vibration analysis of beam on elastic foundation. This numerical method is applied on three different axially loaded cases, namely: 1) one end fixed, the other end simply supported; 2) both ends fixed and 3) both ends simply supported cases. Analytical solutions and frequency factors are evaluated for different ratios of axial load N acting on the beam to Euler buckling load, $N_r$. The application of HPM for the particular problem in this study gives results which are in excellent agreement with both analytical solutions and the variational iteration method (VIM) solutions for all the cases considered in this study and the differential transform method (DTM) results available in the literature for the fixed-pinned case.