• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.557-560
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• 2011

In the present paper, the sloshing resistance performance of an LNG carrier insulation system is evaluated by fluid-structure interaction (FSI) analysis. For this analysis, the arbitrary Lagrangian Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG motion of a KC-1 type LNG carrier cargo tank. In addition, the global-local analysis method is introduced to reduce computational time and cost. The global model is built from shell elements to reduce the sloshing analysis time. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

• Asia pacific journal of information systems
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• 제10권2호
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• pp.23-49
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• 2000

We proposed a conceptual design of the web-based agent model for global supply chain management(GSCM), where agents representing autonomous operational units, such as suppliers, factories, distribution center and customers, cooperate and are coordinated through the information exchange. The agent model assumed the hierarchical federated system. In the federated system, the agents of the same region are grouped and linked to the region-specific facilitator only through which communication between agents is allowed. The facilitator is responsible for monitoring and controlling the conversations consisting of the message flows across the agents. A web-based user presentation was also designed so that human users could involve in collaborative settings into the GSCM multi-agent system. In the conversation protocols which allow for complex coordinated behavior among agents, the KQML was extended to represent the messages. A GSCM scenario where the supply chain is formed upon customer order and supply decision is made was used to demonstrate the dynamics of the conversation protocols.

• 항공우주시스템공학회지
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• 제4권1호
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• pp.19-22
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• 2010

The accuracy and integrity of global navigation satellite systems (GNSS) can be improved by using GNSS augmentation systems. Large ionospheric spatial gradient, during ionosphere storm, is a major threat for using GNSS augmentation systems by increasing the spatial decorrelation between a reference system and users. Ionosphere decorrelation behavior can be analyzed by using dual frequency GPS data. GNSS receivers have their own biases, called inter-frequency bias (IFB) between dual(P1 and P2) frequencies and they must be accurately estimated before computing ionosphere delays. GPS network data in Korea is used to compute each receiver's IFB, and their estimation accuracy and variability are analyzed. IFB estimation methodology to apply for ionosphere gradient analysis is discussed.

• KCI Concrete Journal
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• 제12권1호
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• pp.3-16
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• 2000

A series of dynamic and static tests were conducted to observe the actual responses of a 1:5 scale 3-story reinforced concrete(RC) frame which was designed only for gravity loads. One of the major objectives of these experiments is to provide the calibration to the available static and dynamic inelastic analysis techniques. In this study, the experimental results were simulated by using a nonlinear analysis program for reinforced concrete frame, IDARC-2D. The evaluation of the degree of the simulation leads to the conclusion that while the global behaviors such as story drifts and shears can be in general simulated with the limited accuracy in the dynamic nonlinear analysis, it is rather easy and simple to get the fairly high level of accuracy in the prediction of global and local behaviors in the static nonlinear analysis by using IDARC-2D.

• 대한수학회논문집
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• 제34권4호
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• pp.1365-1388
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• 2019

In this paper we consider a class of nonlinear nonlocal parabolic equations involving p-Laplacian operator where the nonlocal quantity is present in the diffusion coefficient which depends on $L^p$-norm of the gradient and the nonlinear term is of polynomial type. We first prove the existence and uniqueness of weak solutions by combining the compactness method and the monotonicity method. Then we study the existence of global attractors in various spaces for the continuous semigroup generated by the problem. Finally, we investigate the existence and exponential stability of weak stationary solutions to the problem.

• 대한수학회보
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• 제58권5호
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• pp.1109-1127
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• 2021

We study the long-term dynamics for a family of incompressible three-dimensional Leray-α-like models that employ the spectral fractional Laplacian operators. This family of equations interpolates between incompressible hyperviscous Navier-Stokes equations and the Leray-α model when varying two nonnegative parameters 𝜃₁ and 𝜃₂. We prove the existence of a finite-dimensional global attractor for the continuous semigroup associated to these models. We also show that an operator which projects the weak solution of Leray-α-like models into a finite-dimensional space is determining if it annihilates the difference of two "nearby" weak solutions asymptotically, and if it satisfies an approximation inequality.

• 호남수학학술지
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• 제44권2호
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• pp.281-295
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• 2022

This paper deals with the long - time behavior of global bounded solutions for a non-autonomous dispersive-dissipative equation with time-dependent nonlinear damping terms under the null Dirichlet boundary condition. By a new Lyapunov functional and Łojasiewicz-Simon inequality, we show that any global bounded solution converges to a steady state and get the rate of convergence as well, which depends on the decay of the non-autonomous term g(x, t), when damping coefficients are integral positive and positive-negative, respectively.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7663-7668
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• 2013

Background: Skin cancer is a global health problem that can be prevented by protective behavior promoted by nurses. In Turkey, only few studies have examined current knowledge of nurses related to skin cancer and to reveal their attitudes towards sun exposure and current protective behavior. Materials and Methods: This descriptive cross-sectional study was performed from March 11 to May 30, 2013 with a study sample of 310 nurses working in two state hospitals located in Karab$\ddot{u}$k and Safranbolu. Results: Mean age of the nurses was $30.3{\pm}6.89$ years and 96.1% of them had graduated with a Bachelor degree. The participants were predominantly female (n=284). Knowledge level about skin cancer was significantly higher for females compared to males. Conclusions: Nurses do not have sufficient knowledge about skin cancer and are not adequately protecting themselves from ultraviolet light, the primary risk factor for skin cancer. While they demonstrated a responsible attitude towards avoiding sunburn and the need for adequate sun protection, they do not fully appreciate the extent to which the sun can cause skin cancer and that they lack full understanding about the need to protect the skin from burning and to avoid long term sun exposure in Turkey.

• Structural Engineering and Mechanics
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• 제9권3호
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• pp.289-304
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• 2000

This study discusses on the experimental and analytical results of the global buckling tests, carried out on aluminum alloy double layer space grids composed of tubular members, ball joints and connecting bolts at the member ends, with the purpose of demonstrating the effectiveness of a simplified analysis method using an equivalent slenderness ratio for the members. Because very few experiments have been carried out on this type of aluminum space grids, the buckling behavior is investigated experimentally over the post buckling regions using several space grid specimen with various values for the member slenderness ratio. The observed behavior duping the experiments is compared with the analytically obtained results. The comparison is made based on two different schemes; one on the plastic hinge method considering a bending moment-axial force interaction for members and the other on a method using an equivalent slenderness ratio. It is confirmed that the equivalent slenderness method can be effectively applied, even in the post buckling regions, once the effects of the rotational rigidity at the ball joints are appropriately evaluated, because the rigidity controls the buckling behavior. The effectiveness of the equivalent slenderness method will be widely utilized for estimation of the ultimate strength, even in post buckling regions for large span aluminum space grids composed of an extreme large number of nodes and members.

• 경영정보학연구
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• 제11권1호
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• pp.181-196
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• 2009

최근 성능이 우수하고 가격이 저렴한 GPS수신기가 개발되면서 이동객체분석과 공간행태분석에 관한 관심이 높아지고 있다. 이러한 분석을 위한 정보기술과 방법에 관한 연구들이 다각적으로 이루어지고 있지만, 아직 실무에 적용하기에는 한계가 있다. 본 연구는 다차원 모델과 OLAP이라는 데이터분석 기법과 도구들을 이용하여 GPS를 활용한 공간행태분석 방법을 소개하고, 실제 사례를 통해 분석방법 및 분석결과를 제시하였다. 또한, GPS를 활용한 공간행태분석의 유용성과 한계점을 논하였다.