• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.576-585
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• 2002

A three-dimensional Lagrangian explicit time-integration finite element code for analyzing the dynamic impact phenomena was developed. It uses four node tetrahedral elements. In order to consider the effects of strain rate hardening, strain hardening and thermal softening, which are frequently observed in high-velocity deformation phenomena, Johnson-Cook model is used as constitutive model. For more accurate and robust contact force computation, the defense node contact algorithm was adopted and implemented. In order to evaluate the performance of the newly developed three-dimensional hydrocode NET3D, numerical simulations of the oblique impact of mild steel plate by mild steel sphere were carried out. Ballistic limit about various oblique angle between 0 degree and 80 degree was estimated through a series of simulations with different initial velocities of sphere. Element eroding by equivalent plastic strain was applied to mild steel spheres and targets. Ballistic limits and fracture characteristics obtained from simulation were compared with experimental results conducted by Finnegan et al. From numerical studies, the following conclusions were reached. (1) Simulations could successfully reproduce the key features observed in experiment such as tensile failure termed "disking"at normal impacts and outwards bending of partially formed plus segments termed "hinge-mode"at oblique impacts. (2) Simulation results fur 60 degrees oblique impact at 0.70 km/s and 0.91 km/s were compared with experimental results and Eulerian hydrocode CTH simulation results. The Lagrangian code NET3D is superior to Eulerian code CTH in the computational accuracy. Agreement with the experimentally obtained final deformed cross-sections of the projectile is excellent. (3) Agreement with the experimental ballistic limit data, particularly at the high-obliquity impacts, is reasonably good. (4) The simulation result is not very sensitive to eroding condition but slightly influenced by friction coefficient.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.1
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• pp.77-83
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• 2010

Effectiveness of the e-learning hands-on practice in the engineering education depends on the quality of the contents of which simulation is a part and the teaching strategy of the instructor. Instructors who develop and use the simulation-included e-learning content should employ various teaching and learning activities which would make online simulation practice effective. Thus, the strategy for the effective e-learning simulated practice in engineering courses should be known and used effectively. The aim of this paper is to classify the development methods of the simulations and the teaching and learning activities of the development types classified. The comparison of the teaching and learning activities leads to suggestion on teaching and learning strategy for effective use of the online simulation in engineering education.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.100-105
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• 2005

Development of complex discrete event simulators requires cooperation between domain experts and modeling experts who involve the development. With the cooperation the domain experts derive user requirement and modeling experts transform the requirement to a simulation model. This paper proposes a method for consistency verification of simulation model in DEVS formalism against the user requirement in UML diagrams. It also presents an automated tool, called VeriDEVS, which implements the proposed method. Inputs of VeriDEVS are three UML diagrams, namely use case, class and sequence diagrams, and DEVS Graph, all in Visio; outputs of a verification result is represented in PowerPoint files.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.454-461
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• 2010

The new SOLAS regulation permits the alternative design approach for the approval of designs which deviate from those where prescriptive rules apply. The new approach is being promoted by recent advances of noble designs such as those employing large public spaces in passenger ships. From the respect of fire safety, it is needed to show that the level of safety of new design is equivalent to what can be achieved from the prescriptive rules where the fire simulation is regarded to be the essential tool. This paper provides an overview of the process of performance-based design of the smoke extraction system in a cafeteria of a ROPAX. FDS, a CFD fire simulation software is used to show that the field-model software can improve the fire safety over what are expected from prescriptive rule sets or zone-model application.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.316-323
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• 2014

This paper proposes the 3D modeling and simulation technique for predicting the integrated performance of combat vehicle. To consider the practical driving and firing condition of a combat vehicle, the full vehicle model, which can define the six degrees-of-freedom of vehicle motion and various firing angles, is developed. The critical design parameters such as the stiffness and damping coefficient of suspension system are applied to construct the analysis model of vehicle. A simple ballistic model, which incorporates the empirical interior ballistic model and the point mass trajectory model, is built to estimate the firing range and the firing recoil force. To predict the integrated performance and analyze the effect of system parameters, MATLAB/SIM-ULINK model of a combat vehicle for performing the real time simulation is also developed. Several simulation tests incorporating the road bump and the firing recoil force are presented to confirm the effectiveness of the proposed vehicle model.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.279-288
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• 2011

Nursing college students' continuous clinical experiences play an important part in the development of their nursing competency. In reality, it is difficult all of students to have enough clinical experiences. We can think of simulation learning as a solution to this problem. This research attempted to develop learning contents of simulation scenario regarding pediatric nursing. We organized the contents focusing on nursing process. The application of simulation scenario showed that the educational effect. In conclusion, this research suggests that nursing college students can supply high-quality nursing services to children and their families by developing and application of simulation scenario with various cases.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.101-106
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• 2005

It needs to accumulate a store of know-how on the design, precision processing and appraisement for metering pump which is a kind of gear pump fer synthetic fibers. But the period and cost fur development is not effective, because designers experience many trial and error for the pump design and manufacturing process. Therefore, in order to curtail the period and cut down expenses, the analysis and simulation system is required for a designed metering pump. In this study, the pump simulation software was developed with the visual C++ language and the image processing algorithm, and was investigated through a discharge test for the planetary gear type metering pump.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.535-538
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• 2005

Today, most fixed-wing aircrafts are equipped with the antiskid brake system. It can modulate braking moments in the wheels optimally, when an aircraft is landing. So it can reduce landing distance and increase safeties. The antiskid brake system for an aircraft are mainly composed of braking moment modulators (hydraulic control valves) and brake control unit. In this paper, a Mark IV type - fully digital - brake controller is studied. For the development of its control algorithms, a 5-DOF (Degree of Freedom) aircraft landing model is composed in the form of matlab/simulink model at first. Then, braking moment control algorithms using wheel decelerations and slips are made. The developed algorithms are tested in software simulations using state-flow toolboxes in matlab/simulink model. Also, a real-time simulation systems are made, which use hydraulic brake systems of a real aircraft, pressure control valves and its controller as hardware components of HIL(Hardware In-the-Loop) simulation. Algorithms tested in software simulations are coded into the controller and the real-time landing simulations are made in very severe road conditions. The real-time simulation results are presented.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.221-229
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• 2008

The development of computer and multimedia brought out new technology, that is, virtual reality. Computer simulation adaptation among the technologies of the virtual reality is spreaded into air service, motor vehicle, medical science, sports, education, even fashion industry. This study look into 2-dimensional hair-style computer simulation system which is started to common use nowadays and the 3-dimensional system which is under the development. And this study proposed several problems such as heavy 3D system booth and the low price but low qualified camera in order to commercialize the 3D system. This study also suggest several alternative, for instance, the change from object photography method to panoramic photography method, the substitute by middle or high end and high qualified camera.

• KIEAE Journal
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• v.14 no.4
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• pp.69-79
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• 2014

Adverse effects resulting from the development of the environment and to minimize damage to the natural environment and the desire for pleasant scenery and the sense of raising more awareness about May 17, 2007 in accordance with the scenery method is established by each municipality landscape management and landscape planning committee Configure the district planning officer for development projects, including enhancing deliberation scenery method 7 February 2014 and revised in urban areas is more than $30,000m^2$ urban planning landscape projects are all considered by a committee mandated to landscape receive a defined landscape plan for the development was enhanced. Gyeonggi Province in 2007 after the enactment of the scenery method for district planning and landscape planning by strengthening the district planning consideration during deliberations landscape simulation by selecting the view that the proposed mandatory hearing officer from the Joint Committee on Urban construction was done. In this study, Gyeonggi-do district planning business point of view the characteristics of the landscape planning and landscape planning of the center of analysis and as a basis for the evaluation presented.