• Journal of Internet Computing and Services
• /
• v.7 no.3
• /
• pp.133-142
• /
• 2006

The purpose of the multiple key agreement protocol is to get efficiency in computational and communicational aspects compared to multiple executions of single key agreement protocol. However ID based tripartite multiple key agreement protocols have been proposed, it is reported that they can not resist unknown key-share attack or impersonation attack. How to design a secure and efficient ID-based authenticated tripartite multiple key agreement scheme to prevent all kinds of attacks remains an open problem. This paper proposes a multiple key agreement scheme combing the existing single key agreement protocol with a key derivation function. The proposed scheme can not only increase computational efficiency compared to the existing multiple key agreement protocol, but can ensure security of the proposed schemes by using a security proofed single key agreement protocol and key derivation function.

• Molecules and Cells
• /
• v.19 no.1
• /
• pp.46-53
• /
• 2005

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.105-106
• /
• 2020

Recently, a method of deriving an efficient 2D floor plan has been attracting attention for remodeling of old buildings with inaccurate 2D floor plans, and thus, studies on reverse engineering of indoor Point Cloud Date(PCD) have been actively conducted. However, in the case of a indoor PCD, due to interference of indoor objects, available equipment is limited to Mobile Laser Scanner(MLS), which causes a efficiency reduction of data processing. Therefore, this study proposes an automatic derivation algorithm for 2D floor plan of indoor PCD based on pixelation. First, the scanned indoor PCD is projected on the XY coordinate plane. Second, a point distribution of each pixel in the projected PCD is derived using a pixelation. Lastly, 2 floor plan derivation based on the algorithm is performed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.11
• /
• pp.1565-1572
• /
• 2015

Porcine embryonic stem cells (pESCs) have become an advantageous experimental tool for developing therapeutic applications and producing transgenic animals. However, despite numerous reports of putative pESC lines, deriving validated pESC lines from embryos produced in vitro remains difficult. Here, we report that embryo aggregation was useful for deriving pESCs from in vitro-produced embryos. Blastocysts derived from embryo aggregation formed a larger number of colonies and maintained cell culture stability. Our derived cell lines demonstrated expression of pluripotent markers (alkaline phosphatase, Oct4, Sox2, and Nanog), an ability to form embryoid bodies, and the capacity to differentiate into the three germ layers. A cytogenetic analysis of these cells revealed that all lines derived from aggregated blastocysts had normal female and male karyotypes. These results demonstrate that embryo aggregation could be a useful technique to improve the efficiency of deriving ESCs from in vitro-fertilized pig embryos, studying early development, and deriving pluripotent ESCs in vitro in other mammals.

• Communications for Statistical Applications and Methods
• /
• v.16 no.1
• /
• pp.143-155
• /
• 2009

Best subset selection procedure based on mutual information (MI) between a set of explanatory variables and a dependent class variable is suggested. Derivation of multivariate MI is based on normal mixtures. Several types of normal mixtures are proposed. Also a best subset selection algorithm is proposed. Four real data sets are employed to demonstrate the efficiency of the proposals.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.10
• /
• pp.2080-2089
• /
• 2015

In 3D video compression, a disparity vector (DV) pointing a corresponding block position in an adjacent view is a key coding tool to exploit statistical correlation in multi-view videos. In this paper, neighboring block-based disparity vector (NBDV) is shown with detail algorithm descriptions and coding performance analysis. The proposed method derives a DV from disparity motion vector information, obtained from spatially and temporally neighboring blocks, and provides a significant coding gain about 20% BD-rate saving in a texture-video-first-coding scheme. The proposed DV derivation method is adopted into the recent 3D video coding standards such as 3D-AVC and 3D-HEVC as the state-of-the-art DV derivation method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.12
• /
• pp.915-919
• /
• 2013

This is the study on the development of fusion heat dissipation of carbon magnesium materials. The purpose of this study is for effective utilization of heat emission which is the core of LED lighting. The result of study enabled the derivation of side satisfying result of making the surface temperature of lighting to be below $70^{\circ}C$ (actual measurement: $58^{\circ}C$) using magnesium. The lighting products that use magnesium was made possible based on the result of this study. Also from the performance aspect such as light distribution, the measurement of light efficiency demonstrated the level of 90 lm/W. Therefore the commercialization of lighting was made possible and the efficiency could be further enhanced by supplementation of LED performance.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.429-434
• /
• 2008

The objective of this paper is to introduce a project on developing Finish Drawing Automation System. The system aims to improve efficiency of the BIM-based estimation, which is realized by automatic derivation of three-dimensional geometry models of the finish details. First, overall workload differences between the drawing-based estimation methods and the BIM-based methods are analyzed. Second, an automated finish detail design method is proposed as a time-saving measure for the BIM-based estimation, as manual modeling accounts for the most time spent in the model-based estimation process. Finally, the proposed system is evaluated using a case of washboard design.

• Structural Engineering and Mechanics
• /
• v.62 no.1
• /
• pp.85-95
• /
• 2017

This paper presents an explicit analytical iteration method for form-finding analysis of suspension bridges. By extending the conventional analytical form-finding method predicated on the elastic catenary theory, two nonlinear governing equations are derived for calculating the accurate unstrained lengths of the entire cable systems both the main cable and the hangers. And for the gradient-based iteration method, the derivation of explicit calculation for the Jacobian matrix while solving the nonlinear governing equation enhances the computational efficiency. The results from sensitivity analysis show well performance of the explicit Jacobian matrix compared with the traditional finite difference method. According to two numerical examples of long span suspension bridges studied, the proposed method is also compared with those reported approaches or the fundamental criterions in suspension bridge structural analysis, which eventually confirms the accuracy and efficiency of the proposed approach.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.1
• /
• pp.163-170
• /
• 2001

In this paper, a massless link model transmitting external forces is developed to achieve the numerical efficiency in simulation of vehicle suspension systems. Forces acting on links are resolved and transmitted to attached points with a quasi-static assumption. Also, a theoretical derivation and computer implementation of a massless link with bushing elements are proposed. In the massless link with bushing elements, one end is connected to the adjacent body with bushings and the other end is connected with a spherical joint. The deformation of a massless link with bushing elements is theoretically determined by minimizing the potential energy function with quasi-static equilibrium assumption at each time step. Several simulations with a full vehicle model are carried out to compare the efficiency of the developed massless link component. From the results, it is concluded that the proposed approach can reduce the computational time considerably.