• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.19-24
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• 2009

Currently the technique of composite material field is developed day by day. The many kinds industrial facility and life articles are coming to make with the composite material. But still the engineering works field the building and the bridge uses the material which is old era and is making. To here there is a various problem but the biggest problem the theory of the composite material is complicated too and means that the application is been delayed about constructive structure. When the composite material is used widely from constructive field, too with difficult theory in technical expert and easily with the research for the experiment data accumulation is necessary. The tensile and fatigue test of the carbon/epoxy which is a high-class composite material led from the present paper consequently and the change of the intensity coefficient which follows in repeated load researched.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.5
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• pp.573-580
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• 2014

The electrical reliability of the power generation and distribution system of Floating Liquefied Natural Gas vessels has been analyzed according to the operating modes using Electrical Transient Analysis Program in this paper. Electricity is used for the topside processes, cargo pumps for off-loading, thrusters for heading control and marine equipment. It is very important to improve the safety, efficiency, and stability of the electrical power system for successful operation. The voltage variation of the high and the low voltage bus shall be within the primitive limitation range at normal operation loads both in steady state and in the transient state. The power system was simulated and compared with class rule for design verification.

• Annual Conference of KIPS
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• 2003.05c
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• pp.1785-1788
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• 2003

자바의 동적 클래스 로딩은 실행 시간에 소프트웨어 컴포넌트를 동적으로 로딩하기 위한 강력한 메커니즘이다. 다른 시스템에서도 동적 료딩과 링킹을 제공하지만 지연 로딩, 타입 안전 링크, 사용자 정의 클래스 로딩 정책, 그리고 나중 이름공간 둥은 자바가 가진 중요한 특징이다. 자바에서 클래스 로딩의 핵심은 타입 안전에 대한 확신이다. 하지만 자바 가상머신에서 타입 안전에 대한 메커니즘은 매우 복잡하고 또 정확성에 대한 접근이 명확하지 않아서 지금까지 많은 버그가 발생되었고 따라서 타입 안전에 문제가 되어왔다. 본 논문은 간단한 자바 소스 코드를 이용하여 동적인 클래스 로더의 동작을 분석하여 도식화하고, 연산적 의미론으로 추상화하여 이전에 제시되었던 타입 안전에 대한 문제를 분석한다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.720-722
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• 2000

Single phase series commutator motors is widely used in various home appliances, such as vacuum cleaner, electric mixers, electrical tools, etc. This paper deals with the characteristics of single phase series commutator motors of which parameters varied with stator turns and stack length to find optimal electric and magnetic loading. We try to measure these data through the experiments with several prototype motors. The experimental results show some specific stator turns and stack length with which this motor has the highest efficiency.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.35-42
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• 1997

The two-state or mutual M-integral which is derived from tile M-integral and is applicable for two elastic states, is applied for computing all intensity of a singular near-tip field around the vertex of a class of wedge, encountered in adhesive lap joints under mechanical loading. Numerically we verify that a simple auxiliary field associated with every eigenfunction for the composite wedge under consideration exists in the form of the conjugate solution in the sense of tile M-integral. The auxiliary field is then employed for superposition with the elastic field under consideration, and the associated two-state M-integral is computed via the domain integral technique. This enables us to extract the intensity for a singular field information for a singular elastic boundary layer is extracted form the domain integral representation without resort to singular finite element for the wedge vertex.

• Wind and Structures
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• v.15 no.4
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• pp.285-299
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• 2012

This paper describes the development and calibration of a structural monitoring system installed in a 80 meters high steel wind tower supporting a 2.1 MW turbine Wind Class III IEC2a erected in the central part of Portugal. The several signals are measured at four different levels and include accelerations, strains on the tower wall and inside the connection bolts, inclinations and temperature. In order to correlate measurements with the wind velocity and direction and with the turbine operational parameters the corresponding signals are obtained directly from the turbine own monitoring system and are incorporated in the developed system. Results from the system calibration, the structural identification and the initial period of data acquisition are presented in this paper.

• The KSFM Journal of Fluid Machinery
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• v.14 no.4
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• pp.52-56
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• 2011

Small-sized gas turbine engine could be applied to various fields such as propulsion, power generation, machine driving, etc., and Doosan has been developing 5MW class gas turbine engine for power generation since 2005. To verify its design performance and operating characteristics, a gas turbine engine test facility was constructed, and control system was also established to satisfy rapid and reliable control performance. In this paper, the hardware specification and structure of control system for gas turbine engine are introduced, and test result for starting characteristics analysis and loading is also presented.

• Bulletin of the Korean Mathematical Society
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• v.58 no.1
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• pp.71-111
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• 2021

We consider the boundary value problem for the deflection of a finite beam on an elastic foundation subject to vertical loading. We construct a one-to-one correspondence �� from the set of equivalent well-posed two-point boundary conditions to gl(4, ℂ). Using ��, we derive eigenconditions for the integral operator ��M for each well-posed two-point boundary condition represented by M ∈ gl(4, 8, ℂ). Special features of our eigenconditions include; (1) they isolate the effect of the boundary condition M on Spec ��M, (2) they connect Spec ��M to Spec ����,α,k whose structure has been well understood. Using our eigenconditions, we show that, for each nonzero real λ ∉ Spec ����,α,k, there exists a real well-posed boundary condition M such that λ ∈ Spec ��M. This in particular shows that the integral operators ��M, arising from well-posed boundary conditions, may not be positive nor contractive in general, as opposed to ����,α,k.

• Coupled systems mechanics
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• v.10 no.1
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• pp.79-102
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• 2021

In this paper we deal with instability problems of structures under nonconservative loading. It is shown that such class of problems should be analyzed in dynamics framework. Next to analytic solutions, provided for several simple problems, we show how to obtain the numerical solutions to more complex problems in efficient manner by using the finite element method. In particular, the numerical solution is obtained by using a modified Euler-Bernoulli beam finite element that includes the von Karman (virtual) strain in order to capture linearized instabilities (or Euler buckling). We next generalize the numerical solution to instability problems that include shear deformation by using the Timoshenko beam finite element. The proposed numerical beam models are validated against the corresponding analytic solutions.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.123-137
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• 2004

The study on traffic assignment is actively being performed which reflect networks status using time. Its background is increasing social needs to use traffic assignment models in not only hardware area of road network plan but also software area of traffic management or control. In addition, multi-class traffic assignment model is receiving study in order to fill a gap between theory and practice of traffic assignment model. This model is made up of two, one of which is multi-driver class and the other multi-vehicle class. The latter is the more realistic because it can be combined with dynamic model. On this background, this study is to build multidynamic model combining the above-mentioned two areas. This has been a theoretic pillar of ITS in which dynamic user equilibrium assignment model is now made an issue, therefore more realistic dynamic model is expected to be built by combining it with multi-class model. In case of multi-vehicle, FIFO would be violated which is necessary to build the dynamic assignment model. This means that it is impossible to build multi-vehicle dynamic model with the existing dynamic assignment modelling method built under the conditions of FIFO. This study builds dynamic network model which could relieve the FIFO conditions. At the same time, simulation method, one of the existing network loading method, is modified to be applied to this study. Also, as a solution(algorithm) area, time dependent shortest path algorithm which has been modified from existing shortest path algorithm and the existing MSA modified algorithm are built. The convergence of the algorithm is examined which is built by calculating dynamic user equilibrium solution adopting the model and algorithm and grid network.