• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.35-42
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• 1992

The effectiveness of the support-isolation system for the equipment mounted on the primary structure is evaluated to reduce its responses under the earthquake load with considering the interaction between the primary structure and the internal equipment in this paper. A computer code (KBISAP) is developed to analyze the above system using the matrix condensation technique and constant average acceleration method. To evaluate the effectiveness of the support-isolation system, three systems are used in this study as follows: i) fixed-base structure with support-fixed equipment, ii) base-isolated structure with support-fixed equipment and iii) fixed-base structure with support-isolated equipment. The results of case study show that the acceleration of equipment with the support-isolation system is less than that of the support-fixed equipment in the base-isolated structure and significantly reduced the response compared with that of the support-fixed equipment in the fixed-base structure with the reduction factor of 8. The support-isolation system used in this study can reduce the response and also increase the safety margin of the important safety-related internal equipments.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.7-17
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• 1998

Stereolithography is a process used to rapidly produce stereolithographic parts directly from three dimensional CAD models. However design methodologies to create components to be built by stereolithography are different from those required by conventional machining processes. As a typical case in point, the support structures are required to support a component at build stage, but are later removed once building and curing are complete. These structures are used to anchor the component to the platform and to prevent sagging or distortion. This paper deals with the Support Map data structure prepared to find the appropriate regions of supports. Interferences between supports and parts, and support structure themselves as well, are checked and thus the system are searching the statically stable regions to remove the surplus support structures. Cross shaped tooth profiles are designed for easy eliminating the support structures.

• Current Optics and Photonics
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• v.3 no.5
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• pp.429-437
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• 2019

Temperature adaptability is an important metric for evaluating the performance of an optical system. The temperature characteristics of the optical system are closely related to the material and shape of its lens. In this paper, we establish a mathematical model relating the temperature characteristics to the shape and material of the lens. Then a novel assembly structure that can solve the lens constraint and positioning problem is proposed. From those basics, the correctness of the theoretical model and the effectiveness of the assembly structure are verified through simulated analysis of the imaging quality of the optical system, whose operating temperature range is $-60{\sim}100^{\circ}C$.

• Computers and Concrete
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• v.9 no.2
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• pp.99-118
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• 2012

Marine Structures are very costly and need a continuous inspection and maintenance routine. The most effective way to control the structural health is the application of an expert system that can evaluate the importance of any distress on the structure and provide a maintenance program. An extensive literature review, interviews with expert supervisors and a national survey are used to build a decision support system for concrete structures in sea environment. Decision trees are the main rules in this system. The system input is inspection information and the system output is the main cause(s) of distress(es) and the best repair method(s). Economic condition, severity of distress, distress situation, and new technologies and the most repeated classical methods are considered to choose the best repair method. A case study demonstrates the application of the developed decision support system for a type of marine structure.

• Nuclear Engineering and Technology
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• v.41 no.10
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• pp.1323-1332
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• 2009

The IHX (Intermediate Heat eXchanger) for a pool-type SFR (Sodium-cooled Fast Reactor) system transfers heat from the primary high temperature sodium to the intermediate cold temperature sodium. The upper structure of the IHX is a coaxial structure designed to form a flow path for both the secondary high temperature and low temperature sodium. The coaxial structure of the IHX consists of a central downcomer and riser for the incoming and outgoing intermediate sodium, respectively. The IHX of a pool-type SFR is supported at the upper surface of the reactor head with an IHX support structure that connects the IHX riser cylinder to the reactor head. The reactor head is generally maintained at the low temperature regime, but the riser cylinder is exposed in the elevated temperature region. The resultant complicated temperature distribution of the co-axial structure including the IHX support structure may induce a severe thermal stress distribution. In this study, the structural feasibility of the current upper support structure concept is investigated through a preliminary stress analysis and an alternative design concept to accommodate the IHTS (Intermediate Heat Transport System) piping expansion loads and severe thermal stress is proposed. Through the structural analysis it is found that the alternative design concept is effective in reducing the thermal stress and acquiring structural integrity.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.374-379
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• 2003

본 논문에서는 pattern recognition을 위하여 support vector fuzzy inference system을 제안하였다 Fuzzy inference system의 structure와 parameter를 identification 하기 위하여 Support vector machine을 이용하였으며 에러 최소화 기법으로는 gradient descent 방법을 사용하였다. 제안된 SVFIS 방법의 성능을 파악하고자 COIL 이미지를 이용한 3차원 물체 인식 실험을 수행하였다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.182-189
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• 2003

Member actions of long-span suspension bridge due to multiple-support motion are generally larger than those for synchronous support motion frequently employed in aseismic design of a conventional structure. In this study, all the sources of the asynchronous support motion are considered including the loss of coherence and the soil-structure interaction as well as the time delay due to wave propagation of seismic waves. The substructure technique analyzing total soil-foundation-structure system as a superposition of two sub-structures including soil-foundation system and structure itself is employed for the seismic response analysis of the suspension bridge. Finally, an application example is presented to demonstrate applicability of the proposed methodology.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.555-563
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• 2001

Support dynamics are often important in rotordynamic analyses. It may well happen in real situation of machines such as centrifugal pumps or turbines operating on flexible structure. This paper presents the applications of the impedance coupling method and the improved rotor model for including the support effects on the interaction with the rotor. The impedance coupling techniques are based on the FRFs of each substructure. Its dynamic stiffness matrix can be assembled to generate the system matrix, which satisfy the constraint conditions in the connection coordinates. And, the improved rotor uses the simplified spring-mass models as support properties. The equivalent support models are directly incorporated into the finite element rotor model. To verify the suggested analytical procedures, the results are compared to those of the pump system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.253-259
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• 2000

This thesis investigated the behavior of super structure by varying the factors such as the change of pile rigidity, the characteristics of soil and the constraint condition of support. The results of this study are as follows; 1. The pile rigidity in the Fig 3.3 computed by the rotating deformed plane method becomes the elastic range at approximately about 5.1 m (D : 1.0 m) below the ground level. This result is consistent with the previous study that the pile deformation occurs approximately 3 to 6 times pile diameter from the pile head. 2. The values of forces and deformations for the structure-pile system in Y-direction appeared larger than that in X-direction, since the pile rigidity and constraint condition of support were changed as shown Fig.3.5 to 3.8. 3. The current practice for the analysis of structure-pile system has not considered the variation of pile rigidity and the constraint condition of support. So, the analysis of structure-pile system with large difference in super-structure rigidity must includes these factors in both X and Y directions.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.229-239
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• 2003

The design process of machine tools is regarded as a sequential, discrete, and inefficient works as it requires various kinds of design tools and many working hours. This paper describes an integrated design system embedding a design methodology that can support efficiently and systematically the conceptual structural design of machine tools. The system is a knowledge-based design system and has four machine-tool-specific functional modules including configuration design, configuration analysis, structure design, and structural analysis support module. Through the configuration design and analysis module, a machine configuration appropriate for design requirements is selected, and then the arrangement of ribs fer each structural part is decided in the structure design module. Also, the structural analysis support module is used to evaluate design result by utilizing structural analysis software, ANSYS. The system is applied to design of a tapping machine, and shows that the machine structure can be designed fast and conveniently by processing each design step interactively.