• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.519-523
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• 1993

In this paper, the variable structure model following control scheme is proposed for the nonlinear robot manipulator system. The proposed control system guarantees that the system state is in the sliding mode for all time. Therefore, error transient can be prescribed in advance for all time. Furthermore, overall system is globally exponentially stable. Chattering problem is reduced by the introduction of a boundary layer. Simulation results are given to show the usefulness of the proposed control scheme.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.39-50
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• 2019

Since the "Special Law on Cadastral Resurvey" was enforced in 2012, the Cadastral Resurvey Project in South Korea has been promoted in earnest. However, it has been difficult to obtain the following items: a budget for the project, the establishment of land boundaries by increasing/decreasing the area of the parcels of land in the downtown area, the calculation of the adjustment fee, and the analysis of the relationship between the business owner and the landowner in regards to conflicts of opinion. The analysis of Japan's private-public boundary system, which is promoting the Cadastral Resurvey ahead of South Korea, should not attempt to determine complex interests, especially when they are pursuing consensus of the boundary setting portion of the Cadastral Resurvey Project. Therefore, this study shows that there is a need to reduce the number of stakeholders and promote them by using a step-by-step process. The introduction of cost-saving measures for the Cadastral Resurvey through a private-public boundary preliminary investigation is needed. This study suggested the following: link the precision road map construction business using MMS, introduce the preliminary research projects for the Cadastral Resurvey, and gather the important land survey information for the private-public boundary basic survey. In order to establish the utilization base, the researcher proposed linking the downtown area regeneration with the downtown area planning business.

• Journal of the Korean association of regional geographers
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• v.21 no.4
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• pp.704-715
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• 2015

Provincial boundary regions need differentiated strategies from non-provincial boundary regions because they form multilayered regional networks with boundary cites and provinces. This paper aims to analyze the attributions of provincial boundary regions' regional networks in the dimensions of commuters, companies, and government and to explore their political strategies. At commuters level, Okcheon, a case study area, forms the strongest regional networks with Daejeon and does not have any regional network with Honam region. At companies level, it forms the regional network with Daejeon, Gyeonggi, and Chungbuk, and with Daejeon(Donggu, Daedukgu), and Gyeonggi(Bucheon) at government level. This paper suggests the following conclusive policies. First, provincial boundary regions should be postulated as the new policy targets. Second, Population and Housing Census should be constructed pan-regionally as the base data of regional network studies. Lastly, cooperation system among local government of the provincial boundary regions should be constructed.

• Journal of Environmental Science International
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• v.3 no.1
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• pp.17-29
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• 1994

An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

• Journal of applied mathematics & informatics
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• v.35 no.5_6
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• pp.551-563
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• 2017

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $$u^{{\Delta}{\nabla}}(t)+a(t)f(t,u(t))=0,\;t{\in}(0,T),\;{\beta}u(0)-{\gamma}u^{\Delta}(0)=0,\;u(T)={\sum_{i=1}^{m-2}}\;a_iu({\xi}_i),\;m{\geq}3$$, where $a(t){\in}C_{ld}((0,T),\;[0,+{\infty}))$, $f{\in}C([0,T]{\times}[0,+{\infty}),\;(-{\infty},+{\infty}))$, the nonlinear term f is allowed to change sign. We obtain several existence theorems of positive solutions for the above boundary value problems. In particular, our criteria generalize and improve some known results [15] and the obtained conditions are different from related literature [14]. As an application, an example to demonstrate our results is given.

• Bulletin of the Korean Mathematical Society
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• v.50 no.4
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• pp.1235-1242
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• 2013

We give area and height estimates for cmc-graphs over a bounded planar $C^{2,{\alpha}}$ domain ${\Omega}{\subset}\mathbb{R}^3$. For a constant H satisfying $H^2{\mid}{\Omega}{\mid}{\leq}9{\pi}/16$, we show that the height $h$ of H-graphs over ${\Omega}$ with vanishing boundary satisfies ${\mid}h{\mid}$ < $(\tilde{r}/2{\pi})H{\mid}{\Omega}{\mid}$, where $\tilde{r}$ is the middle zero of $(x-1)(H^2{\mid}{\Omega}{\mid}(x+2)^2-9{\pi}(x-1))$. We use this height estimate to prove the following existence result for cmc H-graphs: for a constant H satisfying $H^2{\mid}{\Omega}{\mid}$ < $(\sqrt{297}-13){\pi}/8$, there exists an H-graph with vanishing boundary.

• Interaction and multiscale mechanics
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• v.4 no.3
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• pp.207-217
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• 2011

International efforts have focused recently on the development of tungsten surfaces that can intercept energetic ionized and neutral atoms, and heat fluxes in the divertor region of magnetic fusion confinement devices. The combination of transient heating and local swelling due to implanted helium and hydrogen atoms has been experimentally shown to lead to severe surface and sub-surface damage. We present here a computational model to determine the relationship between the thermo-mechanical loading conditions, and the onset of damage and failure of tungsten surfaces. The model is based on thermo-elasticity, coupled with a grain boundary damage mode that includes contact cohesive elements for grain boundary sliding and fracture. This mechanics model is also coupled with a transient heat conduction model for temperature distributions following rapid thermal pulses. Results of the computational model are compared to experiments on tungsten bombarded with energetic helium and deuterium particle fluxes.

• Journal of Korean Association for Spatial Structures
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• v.2 no.3 s.5
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• pp.71-79
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• 2002

The purpose of this paper is to study the buckling characteristics of elliptical latticed domes under conservative loading conditions. The latticed domes are usually designed in geometrically spherical shape. For this type of latticed domes, many researchers have researched and even the simplified estimation codes for the buckling load level have been available. However, geometrically elliptical latticed domes have been often constructed, and show different buckling characteristics following with geometrical parameters as rise-to-span ratio and so on. Therefore, it is necessary to investigate the general tendency of buckling characteristics of the elliptical latticed domes. In this paper, to find out some buckling characteristics of elliptical latticed domes, height, boundary configuration and gap are used as the shape coefficients. For each model with different parameters, the eigen values and the buckling loads are evaluated.

• Korean Journal of Mathematics
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• v.15 no.1
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• pp.51-57
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• 2007

We prove the existence of a positive solution for the system of the following nonlinear biharmonic equations with Dirichlet boundary condition $$\{{\Delta}^2u+c{\Delta}u+av^+=s_1{\phi}_1+{\epsilon}_1h_1(x)\;in\;{\Omega},\\{\Delta}^2v+c{\Delta}v+bu^+=s_2{\phi}_1+{\epsilon}_2h_2(x)\;in\;{\Omega},$$ where $u^+= max\{u,0\}$, $c{\in}R$, $s{\in}R$, ${\Delta}^2$ denotes the biharmonic operator and ${\phi}_1$ is the positive eigenfunction of the eigenvalue problem $-{\Delta}$ with Dirichlet boundary condition. Here ${\epsilon}_1$, ${\epsilon}_2$ are small numbers and $h_1(x)$, $h_2(x)$ are bounded.

• Bulletin of the Korean Mathematical Society
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• v.53 no.5
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• pp.1585-1596
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• 2016

In this paper we investigate the existence of nontrivial solutions for the following fractional boundary value problem (FBVP) $$\{_tD_T^{\alpha}(_0D_t^{\alpha}u(t))={\nabla}W(t,u(t)),\;t{\in}[0,T],\\u(0)=u(T)=0,$$ where ${\alpha}{\in}(1/2,1)$, $u{\in}{\mathbb{R}}^n$, $W{\in}C^1([0,T]{\times}{\mathbb{R}}^n,{\mathbb{R}})$ and ${\nabla}W(t,u)$ is the gradient of W(t, u) at u. The novelty of this paper is that, when the nonlinearity W(t, u) involves a combination of superquadratic and subquadratic terms, under some suitable assumptions we show that (FBVP) possesses at least two nontrivial solutions. Recent results in the literature are generalized and significantly improved.