• Journal of Hydrogen and New Energy
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• v.33 no.4
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• pp.353-362
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• 2022

In this study, water diffusion in proton exchange membrane fuel cell at open circuit voltage (OCV) was analyzed through experiment. First, the reliability of the micro-sensor (SHT31) was verified. It was concluded the micro-sensor has an excellent reliability at 60℃ and 70℃. After the sensor reliability test, the temperature and relative humidity measurement in bipolar-plate was conducted at OCV. To analyze water distribution and water flux, the temperature and relative humidity was converted into dew point. To the end, it was found water concentration affects water diffusion.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.3
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• pp.194-206
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• 2023

We present families of nonlinear transformations useful for numerical evaluation of weakly singular integrals. First, for end-point singular integrals, we define a prototype function with some appropriate features and then suggest a family of transformations. In addition, for interior-point singular integrals, we develop a family of nonlinear transformations based on the aforementioned prototype function. We take some examples to explore the efficiency of the proposed nonlinear transformations in using the Gauss-Legendre quadrature rule. From the numerical results, we can find the superiority of the proposed transformations compared to some existing transformations, especially for the integrals with high singularity strength.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.175-183
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• 1996

This paper presents three-dimensional robot task using the vision control method. A minimum of two cameras is required to place points on end dffectors of n degree-of-freedom manipulators relative to other bodies. This is accomplished using a sequential estimation scheme that permits placement of these points in each of the two-dimensional image planes of monitoring cameras. Estimation model is developed based on a model that generalizes known three-axis manipulator kinematics to accommodate unknown relative camera position and orientation, etc. This model uses six uncertainty-of-view parameters estimated by the iteration method.

• The KIPS Transactions:PartC
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• v.15C no.1
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• pp.37-44
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• 2008

In order to minimize the signaling delay for a resource reservation on the new routing path after the handover of Mobile Node(MN) is completed, it is important to discover the crossover node where the old and new routing paths meet. With the 크로스오버 노드 being found, the signaling messages only need to be transferred on the changed part of the end-to-end path. The crossover node is generally discovered using the end-to-end Session ID(SID) of the established session between MN and Correspondent Node(CN). However, in the Hierarchical Mobile IPv6(HMIPv6) network, if the Mobile Anchor Point (MAP) reserves the resource by aggregate with the Home Agent(HA), the crossover node discovery cannot be performed in the general way since the aggregate SID that has established between the previous MAP and HA is different from the that of the current MAP and HA after MN's handover. In this paper, we propose a mechanism to discover the crossover node within the tunnel between the MAP and the HA in an HMIPv6 network, assuming that the Next Steps in Signaling(NSIS) is deployed for the resource reservation and the aggregate reservation is applied over the MAP and HA tunnel. The local repair required for the change of path is performed upon the crossover node discovery. The simulation results show that the proposed scheme reduces the signaling delay for the reservation and outperforms the existing scheme with respect to throughput during the handover.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.407-413
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• 2007

In this paper, we definite a generalized weighted Moore-Penrose inverse $A^{+}_{M,N}$ of a given matrix A, and give the necessary and sufficient conditions for its existence. We also prove its uniqueness and give a representation of it. In the end we point out this generalized inverse is also a prescribed rang T and null space S of {2}-(or outer) inverse of A.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.209-214
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• 2004

This paper presents a RFM-based image matching algorithm which put constraints on the search space through the object-space approach. Also, the detail procedure of generating 3-D surface models from the RFM is introduced as an end-user point of view. The proposed algorithm provides the PML (Piecewise Matching Line) for image matching and reduces the search space to within the confined line-shape area.

• Kyungpook Mathematical Journal
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• v.59 no.4
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• pp.665-678
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• 2019

We construct an iteration scheme involving a hybrid pair of mappings, one a single-valued asymptotically nonexpansive mapping t and the other a multivalued nonexpansive mapping T, in a complete CAT(0) space. In the process, we remove a restricted condition (called the end-point condition) from results of Akkasriworn and Sokhuma [1] and and use this to prove some convergence theorems. The results concur with analogues for Banach spaces from Uddin et al. [16].

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2003.06a
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• pp.147-147
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• 2003

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.293-296
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• 2007

This study investigated the out-of-plane elastic buckling load and effective length factor of X-bracing system. The members of X-bracing system which are studied in this paper are rigidly attached to the structure at their end connections, and are pinned or rigidly connected at their point of intersection. The effective length factors are derived for the general case where the tension and compression brace have different material and geometrical properties.

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.97-109
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• 2001

This article is devoted to “forgotten” and rarely used technique of matrix analysis, introduced in 60-70th and enhanced by authors. We will study the matrix trace operator and it’s differentiability. This idea generalizes the notion of scalar derivative for matrix computations. The list of the most common derivatives is given at the end of the article. Additionally we point out a close connection of this technique with a least square problem in it’s classical and generalized case.