• 디지털융복합연구
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• 제20권5호
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• pp.211-220
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• 2022

본 연구는 폐쇄루프 공급망을 최적화하기 위한 녹색 폐쇄루프 공급망 네트워크(GCSN)를 제안한다. GCSN은 물류 유통과정에 투입되는 익스프레스 박스의 재활용에 중점을 두고 연구하였다. 이를 통해 물류공급망 작업의 표준화와 전자상거래 업체의 증가에 따른 익스프레스 박스의 사용의 가속화와 전자상거래 업계의 익스프레스 상자의 재활용을 통한 자원 낭비를 최소화하는 녹색공급망을 추진한다. GCSN은 유통흐름과 자원의 투입요소는 수학식으로 표현하며 LINGO를 사용하여 구현된다. 녹생 즉, 환경 보호의 관점에서 전자상거래 산업의 지속가능한 발전을 견인하는 유통의 과정이다. 또한 자원 부족에 따른 원자재 가격 상승에 대응하고 전자상거래 업체들의 친환경적으로 익스프레스 상자를 투입하는 전략의 필요성을 부각시켰다. 이와 같은 이유로 본 연구는 전자상거래 업체에서 사용하는 재활용이 가능한 익스프레스상자를 연구대상으로 하며, 공급망 네트워크에서 시설 위치와 할당문제도 통합적으로 고찰한다. 마지막으로 본 연구의 결론과 시사점을 도출하였다.

• 전자공학회논문지B
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• 제31B권5호
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• pp.95-107
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• 1994

A new efficient contour following algorithm for connected-component labeling processing is proposed. The basic idea of the algorithm is that the total number of downward chain codes is the same as one of upward chain codes along the closed contour. If the chain code direction is upward, then region start mark is assigned at the chain code departure pixel and if the chain code is downward, then region end mark is assigned at the chain code arrival pixel. The proposed algorithm extracts directly the contour information from only the current direction information of chain. This makes the algorithm simple and fast and requires less memory with comparison to the conventional algorithms.The proposed contour following algorithm can be applied to the various kind of image processing such as region filling, restoration and region feature extraction.

• 한국자동차공학회논문집
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• 제6권3호
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• pp.11-17
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• 1998

In this study, a procedure is presented for the dynamic analysis of a multibody tracked vehicle system. the planner tracked vehicle model used in this investigation is assumed to consist of two kinematically decoupled subsystems, i.e., the chassis subsys- tem and track sub-system. The chassis subsystem includes the chassis frame, sprocket, idler and rollers, while the track subsystem is represented as a closed kinematic chain consisting of rigid links interconnected by revolute joints. The recursive kinematic and dynamic formulation module of the vehicle will be developed.

• 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.

• 대한수학회지
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• 제55권4호
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• pp.1005-1018
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• 2018

Let ${\Sigma}_{g,n,b}$ denote the orientable surface obtained from the closed orientable surface ${\Sigma}_g$ of genus $g{\geq}2$ by deleting the interior of $n{\geq}1$ distinct topological disks and $b{\geq}1$ points. Using the notion of symplectic chain complex, the present paper establishes a formula for computing Reidemeister torsion of the surface ${\Sigma}_{g,n,b}$ in terms of Reidemeister torsion of the closed surface ${\Sigma}_g$, Reidemeister torsion of disk, and Reidemeister torsion of punctured disk.

• 대한기계학회논문집
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• 제18권4호
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• pp.846-855
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• 1994

An effective stiffness, analogous to that of a wound spring, can be created by antagonistic redundant actuation of general closed-chain mechanisms. The qualitative and quantitative characteristics of the effective stiffness are investigated through a Four-bar mechanism, and a load distribution method is introduced which simultaneously guarantees the required system motion and the effective stiffness of the Four-bar mechanism. Furthermore, a simulation is performed to understand the inter-relationship among the effective stiffness, the Four-bar geometry, and the actuation effort. Based on this analysis, the Four-bar synthesis problem for effective stiffness generation is discussed.

• 한국정밀공학회지
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• 제20권4호
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• pp.103-111
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• 2003

The Denavit-Hartenberg symbolic notation provides the framework for the convenient and systematic method for the robot manipulator kinematics, but is limited its use to the lower pair mechanism or to the single loop mechanisms. The Sheth-Uicker notation is its revised and generalized version to be extended fur the entire domain of the link mechanism including the higher pairs. This paper proposes the method that uses the Sheth-Uicker notation fur the robot kinematics modeling. It uses the instantly coincident coordinate system and the closed loop chain fur the coordinate transformation. It enables us to model the velocity kinematics of the robot that has the complex structures such as the ternary links and the wheels in a systematic and rational way. As an implementation of the proposed method, the Jacobian matrices were obtained for not only the robot with two legs and a torso, but a manipulator on a mobile platform.

• 한국정밀공학회지
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• 제22권6호
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• pp.98-108
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• 2005

Conventional robot manipulators actuated by motors with the speed reducer such as the harmonic drive have weakness in the load capacity, since the speed reducer does not have enough strength. To improve this, a new type of robot actuator based on the four-bar-link mechanism driven by the ball screw was constructed. Also, a new type of revolute robot manipulator composed of the developed actuators was developed. But, modelling errors occur due to the off-set from the nominal model since the exact modeling of the complex inertia variation of the four-bar-link actuator is very difficult. To control the proposed robot along the prescribed trajectory, a sliding mode control algorithm was applied with compensation function for the modeling errors. To show performance of the proposed controller, a computer simulation was performed, and its results was presented.

• 대한수학회논문집
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• 제24권1호
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• pp.127-144
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• 2009

Let f be a diffeomorphism of a compact $C^{\infty}$ manifold, and let p be a hyperbolic periodic point of f. In this paper we introduce the notion of $C^1$-stable inverse shadowing for a closed f-invariant set, and prove that (i) the chain recurrent set $\cal{R}(f)$ of f has $C^1$-stable inverse shadowing property if and only if f satisfies both Axiom A and no-cycle condition, (ii) $C^1$-generically, the chain component $C_f(p)$ of f associated to p is hyperbolic if and only if $C_f(p)$ has the $C^1$-stable inverse shadowing property.

• 한국시뮬레이션학회논문지
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• 제15권2호
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• pp.13-21
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• 2006

환경적인 부분에 대한 관심이 증대되면서 기업은 제품을 생산하고 판매하는 것만으로는 기업 이윤을 확보하는 데 어려움을 겪고 있다. 이에 대한 대책으로 이미 사용된 후 수명을 다한 제품과 자원(used products and materials)의 재활용에 대해 주목하게 되었고, 자원의 재활용에 대한 제도는 OECD 국가에서는 이미 보편화되어 있다. 이러한 변화에 발맞추어 자동차 산업에서도 제품의 친환경적인 측면이 강조되고 여러 관련 법규가 제정됨에 따라 상당히 큰 파장을 불러일으키고 있다. 특히 EU는 2005년부터 단계적인 폐차처리 지침을 만들고 이를 지키지 못하는 차량의 경우 더 이상 유럽 지역에 수출을 할 수 없게 하였다. 이에 따라 자동차 업계에서는 자동차의 재활용 및 부품의 재사용에 대한 연구가 활발히 진행되고 있으며, 수명이 다한 제품에 대해 리사이클링(Recycling)과 재사용(Reusing) 하여 제조 기업에게 피드백 하는 닫힌 고리(Closed loop) 형태의 회수물류(Reverse Logistics) 체계를 구축해야 하는 실정이다. 따라서 본 연구에서는 자동차 산업에서의 부품의 재사용과 재활용에 대한 Reverse Logistics 효과를 분석할 수 있는 Closed Loop 방식의 시뮬레이션 모델을 만들고 이를 통해 기존의 Supply Chain과 Reverse Supply Chain을 비교해 봄으로써 Reverse logistics의 도입에 따른 효과를 분석하고, 폐차율을 고려한 자동차 산업의 Reverse logistics의 도입 효과에 대한 분석도 수행하고자 한다. 본 연구의 결과를 통해 자동차 업계의 국내외 역물류의 도입에 따른 효과분석과 국내 폐자동차 관련 정책결정에 필요한 자료가 될 것으로 사료된다.