• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.161-169
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• 2012

In general, Euclidean minimum spanning tree is a tree connecting input nodes with minimum connecting cost. But the tree may not be optimal when applied to real world problems of three dimension. In this paper, three dimension Euclidean minimum spanning tree is proposed, connecting all input nodes of 3-dimensional space with minimum cost. In experiments for 30,000 input nodes with 100% space ratio, the tree produced by the proposed method can reduce 90.0% connection cost tree, compared with the tree by two dimension Prim's minimum spanning tree. In two dimension plane, the proposed tree increases 251.2% connecting cost, which is pointless in 3-dimensional real world. Therefore, the proposed method can work well for many connecting problems in real world space of three dimensions.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.3
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• pp.276-281
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• 2014

The electric power conversion system constructed by connecting two or more power converters in parallel is an advantageous method for making to large capacity and standardization. In this paper, the control method of cross current when three power converters are operated is examined, and it reexamined a preferable system construction method.

• The KIPS Transactions:PartA
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• v.17A no.5
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• pp.213-220
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• 2010

In this paper, a mechanism connecting all input edges with minimum length through Steiner tree is proposed. Edges are convertible into communication lines, roads, railroads or trace of moving object. Proposed mechanism could be applied to connect these edges with minimum cost. In our experiments where input edge number and maximum connections per edge are used as input parameters, our mechanism made connection length decrease average 6.8%, while building time for a connecting solution increase average 192.0% comparing with the method using minimum spanning tree. The result shows our mechanism might be well applied to the applications where connecting cost is more important than building time for a connecting solution.

• International Journal of Automotive Technology
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• v.8 no.3
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• pp.319-325
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• 2007

Preload of critical engine bolts affects the performance and durability of engines. In modern engines that pursue higher power outputs and which are of lighter weight, it becomes more difficult to select an optimal target preload in consideration of various factors such as the role and structural characteristics of joint members, joint load, and fatigue durability of bolts and joint members. A procedure to select the bolt preload using computer-aided engineering technology, especially the finite element method, has been developed. The procedure is illustrated with connecting-rod bolts for which an appropriate preload is known. The selection criteria of target preload and the finite element modeling technique for connecting-rod bolts are also explained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1651-1658
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• 2001

It is necessary to evaluate fatigue strength and reliability of the connecting rod which is core part in automotive engine to assure the high level of durability of automobile. For this purpose, the loading conditions in automotive engine is obtained by the dynamic analysis. Based on these results, the critical section was identified by the finite element analysis. The fatigue strength under constant amplitude was evaluated and the mean of the fatigue limit at R = -2.27 derived from the staircase method was 311.2MPa. And the failure probability( F$\sub$p/ ) derived from the strength-stress interference model is 0.0003% at the 99.99% confidence level and the mean factor of safety was 4.2.

• Tribology and Lubricants
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• v.2 no.2
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• pp.32-43
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• 1986

The mobility method is used for optimizing dynamically-loaded journal bearings. Connecting -rod bearings in both diesel and gasoline engines are optimized by parametric studies of bearing span and clearance. The inertia effect of the connecting-rod is also included in this study. Minimum film thickness, maximum film pressure, and friction loss are calculated to satisfy the design conditions in both engines.

• 전기의세계
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• v.28 no.12
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• pp.41-45
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• 1979

Improvement of power factor is achieved by reactive-current compensation, connecting power condenser to the circuit. This paper describes a method of reactive-current compensation, employing thyristor switching of capacitor banks without any breaker. This method reduces supply transients to the minimum by means of connecting condenser, because thyristor is triggered at zero point in condenser current. The reactive current detection and the experimental system to trigger thyristor at appropriate moment are given. IThe results show the fast reactive-current compensation on the condition of minimum transient.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1994.06b
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• pp.66-71
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• 1994

The motion of dynamically loaded journal in the connecting rod big-end bearings is considered and then equations of motion are derived. Dynamical characteristics of big-end bearings are derived by perturbation method and linearized spring and damping coefficients are calculated. Numerical intergrations of equations of motion ure performed by $\rho$-family method. This paper gives various journal orbits in a big-end bearing depending on external force cycle and bearing parameters

• Steel and Composite Structures
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• v.33 no.6
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• pp.767-776
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• 2019

In this article, a simple and robust multi-objective assessment method to control design angles and node positions connected among steel outrigger truss members is proposed to approve both structural safety and economical cost. For given outrigger member layouts, the present method utilizes general-purpose prototypes of outrigger members, having resistance to withstand lateral load effects directly applied to tall buildings, which conform to variable connecting node and design space deposition. Outrigger layouts are set into several initial design conditions of height to width of an arbitrary given design space, i.e., variable design space. And then they are assessed in terms of a proposed multi-objective function optimizing both minimal total displacement and material quantity subjected to design impact factor indicating the importance of objectives. To evaluate the proposed multi-objective function, an analysis model uses a modified Maxwell-Mohr method, and an optimization model is defined by a ground structure assuming arbitrary discrete straight members. It provides a new robust assessment model from a local design point of view, as it may produce specific optimal prototypes of outrigger layouts corresponding to arbitrary height and width ratio of design space. Numerical examples verify the validity and robustness of the present assessment method for controlling prototypes of outrigger truss members considering a multi-objective optimization achieving structural safety and material cost.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1239-1243
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• 2007

Autonomous Station Control System is automatic route control system of large-scale station. The system has flexibility of system step-by-step construction and expandability. A method of step-by-step construction for Autonomous Station Control System has system expansion and subsystem software expansion. The system has autonomous controllability and autonomous coordinability for system step by step construction. With property for a basis, each of subsystem communicates data field. Also, Each subsystem has its own management system, Autonomous Data Manager to manage itself and coordinate with the others. This paper make clear test method for Autonomous Station Control System expansion and software expansion. The first test method of system increasing construction is single station construction test. The second of method is connecting test the neighbor's Autonomous Station Control System. The third of method is connecting test the Autonomous Line Management System. Also, the test method of software expansion take the case of route control subsystem.