• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.277-282
• /
• 2001

As human-friendly robot techniques improve, the concept of the wearability of robotic arms becomes important. A master arm that detects human arm motion and provides virtual forces to the operator is an embodied concept of a wearable robotic arm. In this study, we design a 7 DOF wearable robotic arm with high joint torques. An operator wearing this robotic arm can move around freely because this robotic arm was designed to have its fixed point at the shoulder part of the operator. The proposed robotic arm uses parallel mechanisms at the shoulder part and the wrist part on the model of the human muscular structure of an upper limb. To reduce the computational load in solving the forward kinematics and to prevent singularity motions of the parallel mechanism, yawing motion of the parallel mechanisms was separated using a slip ling mechanism. The total weight of the proposed robotic arm is about 4 kg. An experimental result of force tracking test for the pneumatic control system and an application example for VR robot are described to show the validity of the robot.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.24 no.3
• /
• pp.272-280
• /
• 2021

We research and develop a SW-based virtual testing product that can be commonly used in the design/development of non-communication EW systems before the production of physical test products. Through this study, we have developed M&S technology to improve the accuracy of EW weapon system analysis/design and to verify and predict the performance of EW equipment, and to develop proven engineering module models and model base systems. It proposes a technology to build an EW M&S framework that can flexibly link/integrate various engineering/engage-level EW heterogeneous M&S systems.

• Steel and Composite Structures
• /
• v.49 no.4
• /
• pp.393-405
• /
• 2023

In this paper, the energy absorption capability of a novel cruciform composite lattice structure was evaluated through the simulation of compression tests. For this purpose, several test samples of Polylactic acid cellular reinforced with continuous glass fibers were prepared for compression testing using the additive manufacturing method of material extrusion. Using a conventional path design for material extrusion, multiple debonding is probable to be occurred at the joint regions of adjacent cells. Therefore, an innovative printing path design was proposed for the cruciform lattice structure. Afterwards, quasistatic compression tests were performed to evaluate the energy absorption behaviour of this structure. A finite element model based on local material property degradation was then developed to verify the experimental test and extend the virtual test method. Accordingly, different combinations of unit cells' dimensions using the design of the experiment were numerically proposed to obtain the optimal configuration in terms of the total absorbed energy. Having brilliant energy absorption properties, the studied cruciform lattice with its optimized unit cell dimensions can be used as an energy absorber in crashworthiness applications. Finally, a cellular structure will be suitable with optimal behavior in crush load efficiency and high energy absorption.

• The KIPS Transactions:PartA
• /
• v.10A no.6
• /
• pp.709-714
• /
• 2003

It is important that the interaction between learners and contents in Educational Contents. But, there is just simple interaction in traditional WBI or CAI. As it is necessary to study for interaction with learners. There is applied more multimedia elements for the fun of learners. But, it is also necessary to study for Network Educational Game Contents which can give virtual environment to learn easily and funny. In this study, Competition Learning Model is designed for network learning environment. We can look at the new view point of Educational Contents by implementation of Network Educational Game Contents and Competition Learning Model.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.1
• /
• pp.57-65
• /
• 1999

The simulation which is larger scale, complex and interactive with clients treat a lot of messages. It can be thinking more efficient distributed simulation than sequential one. The training simulation with multi-users is geographically distributed, and required high cost to operate and maintain system as increasing user requirements. The adaptation of web technology to the simulation can be a way to solves it without cost added. But dynamic web environment can causes causality error of events. This paper is concerned with client-server model, which supports interaction between distributed simulation server and web browser, and it is implemented by Java distributed object model. the result have shown that the distributed simulation is performed correctly on dynamic environment.

• Journal of Distribution Science
• /
• v.18 no.10
• /
• pp.15-23
• /
• 2020

Purpose: Crowdfunding can be a complementary channel in which start-ups or small companies can obtain financial help and take advantage of exploiting the online potential. To activate crowdfunding, it is necessary to consider a consumer's empathic responses. This article examines the role of empathy in the crowdfunding channel platform. We adopted the identification-commitment model to prove the role of empathy. Research design, data, and methodology: Participants were asked to read the charitable crowdfunding campaign. More than 300 young adults completed an online questionnaire and we analyzed it with structural equation modeling (SEM). To find out the role of empathy, we postulate several models which use empathy variable for different purposes. Results: We conclude that empathy has the role of moderator in the identification-commitment model. This means the high empathic response helped the relationship between identification and commitment. However, low empathic response can negatively influence the process of identification to commitment. Conclusions: This study found that virtual empathy is positively related to crowdfunding participation if we can elevate empathy in the crowdfunding channel platform. The findings also show that we need to consider empathic response when we want to raise funds for specific projects such as protecting the natural environment.

• 한국전산유체공학회:학술대회논문집
• /
• 2007.04a
• /
• pp.120-124
• /
• 2007

Helicopters and rotary-wing vehicles encounter a wide variety of complex aerodynamic phenomena and these phenomena present substantial challenges for computational fluid dynamics(CFD) models. This investigation presents the rotor aerodynamic analysis items for the helicopter development and variety aerodynamic analysis methods to provide the better solution to researchers and helicopter developers between aerodynamic problems and numerical aerodynamic analysis methods. The numerical methods to make an analysis of helicopter rotor are as below - CFD Modelling : actuator disk model, BET model, fully rotor model,... - Grid : sliding mesh, chimera mesh / structure mesh, unstructure mesh,... - etc. : panel method periodic boundary, quasi-steady simulation, incompressible,... The choice of CFD methodology and the numerical resolution for the overall problem have been driven mostly by available computer speed and memory at any point in time. The combination of the knowledge of aerodynamic analysis items, available computing power and choice of CFD methods now allows the solution of a number of important rotorcraft aerodynamics design problems.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2002.05a
• /
• pp.274-277
• /
• 2002

To transmit users' intentions that vary with each person, intuitive and hi-directional interactions between users and a computer are necessary. We considered these interactions by dividing them into two spaces, physical space and informational space. Informational space supports human thinking process by arranging and visualizing much information. Physical space reproduces the real world where various restrictions exist to virtual space. From the viewpoint of three aspects - contents model, kansei model and context model - we defined the style of the interaction between user and multimedia database. In this paper, for the purpose of examining the way to realize the interaction based on these models, we developed interior design coordination support system and garden coordination system, and then evaluated them.

• Advances in nano research
• /
• v.7 no.6
• /
• pp.419-429
• /
• 2019

The effect of an increasing percentage of nanofiller (glass cenosphere) with Glass/Epoxy hybrid composite curved panels modeled mathematically using the multiscale concept and subsequent numerical eigenvalues of different geometrical configurations (cylindrical, spherical, elliptical, hyperboloid and flat) predicted in this research article. The numerical model of Glass/Epoxy/Cenosphere is derived using the higher-order polynomial type of kinematic theory in association with isoparametric finite element technique. The multiscale mathematical model utilized for the customized computer code for the evaluation of the frequency data. The numerical model validation and consistency verified with experimental frequency data and convergence test including the experimental elastic properties. The experimental frequencies of the multiscale nano filler-reinforced composite are recorded through the impact hammer frequency test rig including CDAQ-9178 (National Instruments) and LABVIEW virtual programming. Finally, the nano cenosphere filler percentage and different design associated geometrical parameters on the natural frequency data of hybrid composite structural configurations are illustrated through a series of numerical examples.

• Nuclear Engineering and Technology
• /
• v.51 no.4
• /
• pp.968-976
• /
• 2019

This paper presents a number of verification case studies for a recently developed sensitivity/uncertainty code package. The code package, ROMUSE (Reduced Order Modeling based Uncertainty/Sensitivity Estimator) is an effort to provide an analysis tool to be used in conjunction with reactor core simulators, in particular the Virtual Environment for Reactor Applications (VERA) core simulator. ROMUSE has been written in C++ and is currently capable of performing various types of parameter perturbations and associated sensitivity analysis, uncertainty quantification, surrogate model construction and subspace analysis. The current version 2.0 has the capability to interface with the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) code, which gives ROMUSE access to the various algorithms implemented within DAKOTA, most importantly model calibration. The verification study is performed via two basic problems and two reactor physics models. The first problem is used to verify the ROMUSE single physics gradient-based range finding algorithm capability using an abstract quadratic model. The second problem is the Brusselator problem, which is a coupled problem representative of multi-physics problems. This problem is used to test the capability of constructing surrogates via ROMUSE-DAKOTA. Finally, light water reactor pin cell and sodium-cooled fast reactor fuel assembly problems are simulated via SCALE 6.1 to test ROMUSE capability for uncertainty quantification and sensitivity analysis purposes.