• 한국정보시스템학회지:정보시스템연구
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• 제24권4호
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• pp.43-60
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• 2015

Purpose This study intended to introduce new approaches to identify the intellectual structure of supply chain management(SCM) researches, which combines author co-citation analysis(ACA) and social network analysis(SNA). Design/methodology/approach We searched RISS(www.riss.kr) and NDSL(www.ndsl.or.kr) database and collected 292 academic papers on supply chain management between 2001 and 2011. Among 9,637 references of these papers, we analyzed 1,848 references that were published by domestic authors. We produced a correlation matrix of 32 author co-citation matrix and conducted multi-variate statistical analysis such as factor analysis. We also performed social network analysis to identify the main researchers in SCM. Findings We found four main sub-areas of supply chain management research: SCM adoption factors, logistics, SCM performance, and SCM structure. We could present the authors who played important roles within the network by using SNA indicators. The finding of this research also suggests more collaborations among domestic researchers are required to overcome the low co-citation rates among domestic authors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.631-637
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• 2005

This paper presents a stiffness analysis method for a low-DOF parallel manipulator, which takes into account of elastic deformations of joints and links. A low-DOF parallel manipulator is defined as a spatial parallel manipulator which has less than six degrees of freedom. Differently from the case of a 6-DOF parallel manipulator, the serial chains in a low-DOF parallel manipulator are subject to constraint forces as well as actuation forces. The reaction forces due to actuations and constraints in each limb can be determined by making use of the theory of reciprocal screws. It is shown that the stiffness model of an F-DOF parallel manipulator consists of F springs related to the reciprocal screws of actuations and 6-F springs related to the reciprocal screws of constraints, which connect the moving platform to the fixed base in parallel. The $6{times}6$ stiffness matrix is derived, which is the sum of the stiffness matrices of actuations and constraints. The six spring constants can be precisely determined by modeling the compliance of joints and links in a serial chain as follows; the link can be considered as an Euler beam and the stiffness matrix of rotational or prismatic joint can be modeled as a $6{times}6$ diagonal matrix, where one diagonal element about the rotation axis or along the sliding direction is zero. By summing the elastic deformations in joints and links, the compliance matrix of a serial chain is obtained. Finally, applying the reciprocal screws to the compliance matrix of a serial chain, the compliance values of springs can be determined. As an example of explaining the procedure, the stiffness of the Tricept parallel manipulator has been analyzed.

• 제어로봇시스템학회논문지
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• 제13권4호
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• pp.320-328
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• 2007

This paper presents a stiffness modeling of a low-DOF parallel robot, which takes into account of elastic deformations of joints and links, A low-DOF parallel robot is defined as a spatial parallel robot which has less than six degrees of freedom. Differently from serial chains in a full 6-DOF parallel robot, some of those in a low-DOF parallel robot may be subject to constraint forces as well as actuation forces. The reaction forces due to actuations and constraints in each serial chain can be determined by making use of the theory of reciprocal screws. It is shown that the stiffness of an F-DOF parallel robot can be modeled such that the moving platform is supported by 6 springs related to the reciprocal screws of actuations (F) and constraints (6-F). A general $6{\times}6$ stiffness matrix is derived, which is the sum of the stiffness matrices of actuations and constraints, The compliance of each spring can be precisely determined by modeling the compliance of joints and links in a serial chain as follows; a link is modeled as an Euler beam and the compliance matrix of rotational or prismatic joint is modeled as a $6{\times}6$ diagonal matrix, where one diagonal element about the rotation axis or along the sliding direction is infinite. By summing joint and link compliance matrices with respect to a reference frame and applying unit reciprocal screw to the resulting compliance matrix of a serial chain, the compliance of a spring is determined by the resulting infinitesimal displacement. In order to illustrate this methodology, the stiffness of a Tricept parallel robot has been analyzed. Finally, a numerical example of the optimal design to maximize stiffness in a specified box-shape workspace is presented.

• Journal of Microbiology
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• 제40권1호
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• pp.70-76
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• 2002

Proviral DNAs from HIV-1-infected CD4+ T cells (Molt/LAV cells) were amplified and detected in infected individual cells using polymerase chain reaction and in rifu hybridization. In this in situ PCR, three parameters were considered to achieve effective amplification and retention of amplificants inside the cells by making high molecular weight PCR products intracellularly, forming agarose matrix against the cells, and maintaining the appropriate PCR temperature profile. Over the cycles of ampliHcationl tailed primers with complementary overhanging sequences at their 5' sides manufactured high molecular weight products by using short primary products as a repeating unit. Agarose matrix could prevent the diffusion of the amplificants from the cells. Use of Thermanox coverslip inside the PCR tube offered target cells a similar temperature profile to that of conventional PCR in solution.

• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.5-10
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• 2001

A method is proposed to obtain the Jacobian matrix of the 5 -bar parallel manipulator by employing the orthogonality between position and velocity vectors of rotating rigid-body around a fixed point. The dynamics of the 5-bar parallel manipulator is analyzed and utilized to design the computed-torque controller by developing a transformation matrix of the passive joints with respect to the active ones. In experimental demonstration, it shows that high-speed and accuracy tasks are performed by the proposed computed-torque control.

• 대한수학회보
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• 제44권4호
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• pp.721-729
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• 2007

In this paper, we have characterizations of idempotent matrices over general Boolean algebras and chain semirings. As a consequence, we obtain that a fuzzy matrix $A=[a_{i,j}]$ is idempotent if and only if all $a_{i,j}$-patterns of A are idempotent matrices over the binary Boolean algebra $\mathbb{B}_1={0,1}$. Furthermore, it turns out that a binary Boolean matrix is idempotent if and only if it can be represented as a sum of line parts and rectangle parts of the matrix.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4568-4584
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• 2016

Steganography based on text generation has become a hot research topic in recent years. However, current text-generation methods which generate texts of normal style have either semantic or syntactic flaws. Note that texts of special genre, such as poem, have much simpler language model, less grammar rules, and lower demand for naturalness. Motivated by this observation, in this paper, we propose a text steganography that utilizes Markov chain model to generate Ci-poetry, a classic Chinese poem style. Since all Ci poems have fixed tone patterns, the generation process is to select proper words based on a chosen tone pattern. Markov chain model can obtain a state transfer matrix which simulates the language model of Ci-poetry by learning from a given corpus. To begin with an initial word, we can hide secret message when we use the state transfer matrix to choose a next word, and iterating until the end of the whole Ci poem. Extensive experiments are conducted and both machine and human evaluation results show that our method can generate Ci-poetry with higher naturalness than former researches and achieve competitive embedding rate.

• Nuclear Engineering and Technology
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• 제26권2호
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• pp.277-284
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• 1994

폐기물 고화체로부터 주위의 Near-field로의 단일 핵종의 이동에는 많은 연구가 수행되고 있으나, 방사성 핵종 사슬의 이동에 관한 연구는 매우 제한되어 있다. 본 논문에서는 조화 유출되는 방사성 핵종 사슬의 이동을 분석하고, 유한 크기의 다공성 매질에서의 일반적인 비순환 해석해를 제시하였다. 또한 이해를 사용후 핵연료에서 가장 중요한 핵종사슬인 $^{234}$ U$\longrightarrow$$^{230}$ Th$\longrightarrow$$^{226}$ Ra 에 적용하여 보았다. 본 연구는 방사성 폐기물의 처분장 성능평가에 유용하고 중요하게 사용될 것이다.

• 생명과학회지
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• 제8권3호
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• pp.235-240
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• 1998

Matrix metalloproteinases(MMP)는 배발생 및 재조직화 등의 정상적인 생체형성과 관절염, 암전이, 치근막염, 골조송증 등의 질병과정에서 collagen이나 proteoglycan과 같은 세포외기질의 구성성분을 분해하는 아연(zinc)효소군이다. 지금까지 다양한 종에서 mmp의 유전자가 클로닝되고 그 기능이 연구되어 왔지만 아직 어류에서는 연구결과가 보고된 바가 없다. 본 연구에서는 한국의 부산연안에 많은 연골어유 투툽상어(Scylliorhinus toraxzame)로부터 RT-PCR(reverse transcriptase dependent polymerase chain reaction)의방법으로 mmp cDNA의 일부를 클로닝하였다. 이것은 염기서열에서 인간, 쥐 및 닭의 membrane type matrix matalloproteinase-3(mt3-mmps)의 염기서열과 74% 동일성을 보이며, 아미노산서열에서는 90%이상의 동일성을 갖고 있다. 또한 MMP에 나타나는 cysteine switch domain, zinc binding domain(HExGH motif), propeptide cleavage site, and RRKR motif등을 가지고 있다. 이러한 결과로부터 본 연구에서 클로닝된 RT-PCR단편은 두툽상어의 mt3-mmp 또는 이와 유사한 유전자의 cDNA이라 믿어진다.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.457-462
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• 2017

A linear carbon chain with pure sp hybridization has been intensively studied for the application of its intrinsic electrical properties to electronic devices. Owing to the high chemical reactivity derived from its unsaturated bond, encapsulation by carbon nanotubes (CNT) is provided as a promising method to stabilize the geometry of the linear carbon chain. Although the influence of CNT on the carbon chain has extensively been studied in terms of both electronic structure and geometries, the electron transport properties has not been discussed yet. In this regard, we provide the systematic atomic-scale analyses of the properties of the linear carbon chain within CNT based on a computational approach combining density-functional theory (DFT) and matrix green function (MGF) method. Based on the DFT calculations, the influence of CNT on electronic structures of the linear carbon chain is provided as well as its electrical origin. Via MGF calculations, we also identify the electron transport properties of the carbon chain - CNT complex.