• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.224-228
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• 1999

When we construct a manufacturing plant, optimal design is very important. This paper is to simulate an engine manufacturing flow line for commercial vehicle. The parameters we consider in simulation include facility downtime, tool change time, buffer size between consecutive stations, and time to repair the facility. We use AutoMod to compare the alternatives. The objective is to minimize the total cost. Simulation results provide significant cost saving by improving the current design and policy.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.240-249
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• 2009

HRSG(Heat Recovery Steam Generator) building is large enclosed structure included various heat sources. This building needs to appropriately keep internal air temperature for worker's safety and operability of control devices. In this study, ventilation analysis is performed to find proper ventilation method for temperature control. Ventilation analysis is applied to entire internal space of the building with standard $k-{\varepsilon}$ model and enhanced wall treatment because of large size of the structure. And the ventilation method is considered natural and forced convection with two louver structures which has damper or not. Louver structure affect directly air circulation in near HRSG and lower region of the building. Forced ventilation provides strong inertial force which cause upward airflow. From the analysis, it is found that design requirement for internal air temperature can be satisfied by forced ventilation method with louver structure without damper.

• Structural Engineering and Mechanics
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• v.86 no.1
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• pp.93-107
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• 2023

In this paper, a density based topology optimization is proposed for generating of supports required in additive manufacturing to maintain the overhanging regions of main structures during layer by layer fabrication process. For this purpose, isogeometric analysis method is employed to model geometry and structural analysis of main and support structures. In order to model the problem two cases are investigated. In the first case, design domain of supports can easily be separated from the main structure by using distinct isogeometric patches. The second case happens when the main structure itself is optimized by using topology optimization and the supports should be designed in the voids of optimum layout. In this case, in order to avoid boundary identification and re-meshing process for separating design domain of supports from main structure, a parameterization technique is proposed to identify the design domain of supports. To achieve this, two density functions are defined over the entire domain to describe the main structure and supporting areas. On the other hand, since supports are under gravity loads while main structure and its stiffness is not completed during manufacturing process, in the proposed method, stiffness of the main structure is considered to be trivial and the gravity loads are also naturally applied to design support structures. By doing so, the results show reasonable supports are created to protect, continuously, overhanging surfaces of the main structure. Several examples are presented to demonstrate the efficiency of the proposed method and compare the results with literature.

• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.18-26
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• 2008

Shipbuilding industries have been struggling to reduce production time and cost of their products in many aspects. Manufacturing systems have been changed, new production lines and robots have been installed, and new planning and scheduling systems have been adopted in order to achieve shorter time-to-market and higher productivity. Simulation based manufacturing, digital manufacturing, or virtual manufacturing simulation, whatever the name means, is an approach to achieve such a goal. In order to improve productivity in a shipbuilding process at a shipyard, a digital shipyard development has been driven. This paper proposed how to implement the digital shipyard, what to do with it, and what to obtain from it. This digital shipyard will help simulate and optimize the entire shipbuilding life cycle with its virtual environment through shipbuilding process from the initial development stage to the launch.

• Transactions of Materials Processing
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• v.14 no.7 s.79
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• pp.613-618
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• 2005

The paper is concerned with the process design and the die design for manufacturing the preform of a large pressure vessel. The cold-working processes are introduced to improve the fatigue strength and to simplify the manufacturing process. By the finite element simulation, the parameter design is carried out, which is subjected to constraints such as the blank sire, press capacity and other minor limitations. The proposed design results are verified by the model experiments, in which the model is scaled down to one tenth of the original size.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.7
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• pp.97-104
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• 2021

LASOX is a cutting technology used to dismantle nuclear power plants. The core component of the laser-assisted oxygen hybrid cutting process is the supersonic nozzle. To design optimized supersonic nozzles, an experimental design was established and computational fluid dynamics was used to analyze the supersonic nozzles. The main factors affecting the supersonic nozzle performance were identified using Minitab. Further, the correlations and interactions between the main factors of the supersonic nozzle design were analyzed. The fluid analysis results were examined for the major factors and standardized response variables as well as main effects to ensure suitability of the supersonic nozzle design for the laser-assisted oxygen cutting process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.6
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• pp.12-18
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• 1998

The optimal design for stiffened laminate composite cylindrical shells under combined loads is studied by a nonlinear mathematical search algorithm. The optimal design is accomplished with the CONMIN. several types of buckling modes with maximum allowable stresses and strains are included as constraints in the optimal design process, such as general buckling, panel buckling with either stringers or rings smeared out, local skin buckling, local crippling of stiffener segments. Rectangular or T type stringers and rectangular rings are used for stiffened laminate composite cylindrical shells.

• Smart Structures and Systems
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• v.11 no.3
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• pp.283-297
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• 2013

An innovative cage for spinal fusion surgery is presented within this work. The cage utilizes shape memory alloy for its hinge actuation. Because of the use of SMA, a smaller incision is needed which makes the cage deployment minimally invasive. In the development of the cage, a model for predicting the torsional behavior of SMAs was developed and verified experimentally. The prototype design of the cage was developed and manufactured. The prototype was subjected to static tests per ASTM specifications. The cage survived all of the tests, alluding to its safety within the body.

• Korean Journal of Computational Design and Engineering
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• v.14 no.1
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• pp.42-49
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• 2009

Virtual manufacturing technology has been applied in actual production sites with the development of virtual reality technology. However, the current virtual manufacturing technology requires experts for application of the system. Furthermore, the sense of reality is diminished as the entire simulation is driven by virtual objects. In contrast, mixed reality can visualize virtual objects and an actual work place simultaneously, and thus the sense of reality of the virtual manufacturing simulation can be improved. This paper introduces a method that applies mixed reality in the manufacturing process, and proposes a method to adapt general safety sign post in the factory instead of a black square marker for visual fiducial recognition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.511-512
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• 2008