• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.117-126
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• 2011

The buckling assessment of plate panels described in common structural rules (CSR) is to be determined according to the buckling utilization factor with hull girder stresses calculated on net hull girder sectional properties. As the thickness requirement for the buckling assessment of plate panels is not explicitly given in CSR, a lot of time is spent to find the proper thickness of plate panels until reaching to an allowable buckling utilization factor. In this study, in order to reduce time and cost, the thickness requirement of plate panels satisfying buckling assessment was derived. The structural design system included with the thickness requirement for buckling assessment was developed. The system is called as Oil-tanker Automated Structural Investigation System (OASIS). The design result of longitudinal strength members using OASIS was verified by Nauticus Hull which is the rule scantling software of DNV. Finally, optimum design of a double hull tanker for the minimum weight using OASIS was presented.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.459-466
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• 2002

Modern embedded system employs a hybrid architecture which contains a general micro processor and reconfigurable devices such as FPGAS to retain flexibility and to meet timing constraints. It is a hard and important problem for embedded system designers to explore and find a right system configuration, which is known as design space exploration (DSE). With DES, it is possible to predict a final system configuration during the design phase before physical implementation. In this paper, we implement a timing analysis simulator for a DSE on a hybrid embedded system. The simulator, integrating exiting timing analysis tools for hardware and software, is designed by extending Y-chart approach, which allows quantitative performance analysis by varying design parameters. This timing analysis simulator is expected to reduce design time and costs and be used as a core module of a DSE for a hybrid embedded system.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.49-62
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• 2015

In this study we have proposed the prototype of design support device for architectural design assessment using the building information modeling(BIM) data and the augmented reality(AR) technology. The proposed system consists of novel hardware composition with the transparent display, the mock-up model and the digital architectural model in the new shape of frame. The removal of background and the correction of viewer point in the capture video are proposed in order to use the transparent display in AR application. The BIM data formats are reviewed to be converted for using in AR application. Also the proposed system can be expanded to multi-user collaboration system from two user system through the suggested hardware and software compositions. The results of this study will be applied to use the mock-up model and digital architectural model in order to carry out the design assessment process efficiently and economically in the architectural design field.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.269-281
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• 2014

This paper examines the suitability of using the Computational Fluid Dynamics (CFD) tools, ANSYS-CFX, as an initial analysis tool for predicting the drag and propulsion performance (thrust and torque) of a concept underwater vehicle design. In order to select an appropriate thruster that will achieve the required speed of the Underwater Disk Robot (UDR), the ANSYS-CFX tools were used to predict the drag force of the UDR. Vertical Planar Motion Mechanism (VPMM) test simulations (i.e. pure heaving and pure pitching motion) by CFD motion analysis were carried out with the CFD software. The CFD results reveal the distribution of hydrodynamic values (velocity, pressure, etc.) of the UDR for these motion studies. Finally, CFD bollard pull test simulations were performed and compared with the experimental bollard pull test results conducted in a model basin. The experimental results confirm the suitability of using the ANSYS-CFX tools for predicting the behavior of concept vehicles early on in their design process.

• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.79-86
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• 2005

Increasing network traffic and multimedia application services need realtime analysis of network traffic for improvement of QoS and effective management of network resource. Because difficulty of measurement based on software method, study of meter architecture for efficient capture function is necessary. Therefore we design and implement hardware metering system for efficient packet capture using embedded linux. And we analyze required bandwidth of system bus and memory for 10Gbps traffic through simulation.

• International Journal of Aerospace System Engineering
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• v.4 no.1
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• pp.13-21
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• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.219-224
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• 2010

Recycling issue for the construction wastes is gradually important to future society. Recently, a star screen has been developed to use for this purpose, however some modifications were needed to enhance the separation accuracy. The objective of study is to evaluate and predict separation ability by verifying the effect for the modified shapes of the screen part. Two analysis models of the screen part were established using commercial software ADAMS to simulate the dynamic interaction of waste particles. Results showed that spacer and gear shapes directly affected separation ability. The modified spacer shapes were much higher screening rate with comparison to default shape. Screening ability for the half number of gear type was greater than other types. Therefore, modification of the design of screen part will be required to achieve better separation ability.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.579-584
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• 2004

In this paper, we present the mechanical, electrical system design and system integration of controllers including sensory devices of the humanoid, KHR-2 (KAIST Humanoid Robot - 2). We have developed KHR-2 since 2003. Total number of DOF of KHR-2 is 41. Each arm including a hand has 11 DOF and each leg has 6 DOF. Head and trunk also has 6 DOF and 1 DOF respectively. In head, two CCD cameras are used for eye. To control all axes efficiently, distributed control architecture is used to reduce computation burden of main controller and to expand devices easily. So we developed the sub-controller as a servo motor controller and a sensor interfacing devices using microprocessor. The main controller attached its back communicates with sub-controllers in real-time by CAN (Controller Area Network) protocol. We used Windows XP as its OS (Operation System) for fast development of main control program and easy extension of peripheral devices. And RTX HAL extension commercial software is used to realize the real-time control in Windows XP environment.

• Journal of Ocean Engineering and Technology
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• v.28 no.1
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• pp.85-92
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• 2014

Offshore fields are increasingly important for the development of offshore resources due to the growing energy needs. However, an offshore field for oil and gas production has difficult development conditions, e.g., high temperature, high pressure, sweet/sour compositions of fluids, etc. Corrosion is one of the biggest issues for offshore pipeline engineering. In this study, a Corrosion Resistant Alloy (CRA) pipe for corrosion prevention was investigated through its global demand and trends, and three types of CRA pipelines were introduced with detailed explanations. The usefulness of CRA was also evaluated in comparison to a carbon steel pipeline in terms of the structural strength, cost, and other factors. Offshore pipeline engineering, including mechanical design and verification of the results through an installation analysis based on numerical software, was performed for the carbon steel type and solid CRA type. The results obtained from this study will be useful data for CRA pipeline designers and researchers.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.377-382
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• 2010

In lunar explorer development program, computer simulator is necessary to provide virtual environments that vehicle confronts in lunar transfer, orbit, and landing missions, and to analyze dynamic behavior of the spacecraft under these environments. Objective of simulation differs depending on its application in spacecraft development cycle. Scope of use cases considered in this paper includes simulation of software based, processor and/or hardware in the loop, and support of ground-based flight test of developed vehicle. These use cases represent early phase in development cycle but reusability of modeling results in the next design phase is considered in defining requirements. A simulator architecture in which simulator platform is located in the middle and modules for modeling, analyzing, and three dimensional visualizing are connected to that platform is suggested. Baseline concepts and requirements for simulator development are described. Result of trade study for selecting simulation platform and approaches of defining other simulator components are summarized. Finally, characters of lunar elevation map data which is necessary for lunar terrain generation is described.