• ETRI Journal
• /
• v.25 no.1
• /
• pp.25-33
• /
• 2003

This paper describes interactive dynamic simulation schemes for articulated bodies in virtual environments, where user interaction is allowed through a haptic interface. We incorporated these schemes into our dynamic simulator I-GMS, which was developed in an object-oriented framework for simulating motions of free bodies and complex linkages, such as those needed for robotic systems or human body simulation. User interaction is achieved by performing push and pull operations with the PHANToM haptic device, which runs as an integrated part of I-GMS. We use both forward and inverse dynamics of articulated bodies for the haptic interaction by the push and pull operations, respectively. We demonstrate the user-interaction capability of I-GMS through on-line editing of trajectories for 6-dof (degrees of freedom) articulated bodies.

• Journal of International Society for Simulation Surgery
• /
• v.1 no.1
• /
• pp.19-22
• /
• 2014

As computer technology develops and this is applied to medical image field, three dimensional image reconstruction technology using computer simulation is utilized in various categories that include anatomical study and biomechanics study of human body. Especially orthopedic surgeons are able to investigate biomechanical function and be provided information for operations with this technology in terms of ligament reconstruction of knee. And this technology can be utilized in preparing preoperative planning and instructions and training. This review is about three dimensional image reconstruction technology which is utilized in ligament reconstruction of knee.

• Earthquakes and Structures
• /
• v.23 no.6
• /
• pp.535-547
• /
• 2022

Handball sport, as its name postulates, is a team sport which highly physical workout. During a handball play, several ball impacts are applied on the hands resulting vibration in the forearm, upper arm, shoulders and in general in whole body. Hand has important role in the handball's game. So, understanding about the dynamics and some issues that improve the stability of the hand is important in the sport engineering field. Ulna and radius are two parallel bones in lower arm of human hand which their ends are located in elbow and wrist joint. The type of the joint provides the capability of rotation of the lower arm. These two bones with their ends conditions in the joints constructs a 4-link frame. The ulna is slightly thinner than radius. So, understanding about hand kinematics in handball's game is an important thing in the engineering field. So, in the current work with the aid of a multi-physics simulation, dynamic stability analysis of the ulna and radius bones will be presented in detail.

• Journal of Magnetics
• /
• v.22 no.2
• /
• pp.238-243
• /
• 2017

In this research, we report the preliminary results of an insertional type parallel transmission (pTx) array that has 7-elements that are placed in the space above a patient table as a transmit (Tx) coil to give an RF transmission ($B_1{^+}$) field for the body object of a 3 Tesla (T) MRI system. In previous research, we have tried to compare the performances of different coil elements and array geometries for a pTx body image. Based on these results, we attempt to obtain a human image with the proposed pTx array. Through the simulation and experimental results, we introduce a possible structure of multi-channel Tx array and verify the utility of a multi-channel Tx body image using $B_1{^+}$ shimming. The insertional pTx array, combined with a receiver (Rx) array coil, provides an enhanced $B_1{^+}$ field homogeneity in a large ROI image as a result of $B_1{^+}$ shimming applied over the full body size object. Through this research, we hope to determine the usefulness of the proposed insertional type RF coil combination for 3 T body imaging.

• Journal of radiological science and technology
• /
• v.38 no.1
• /
• pp.17-21
• /
• 2015

Total body irradiation(TBI) and chemotherapy are the pre-treatment method of a stem cell transplantations of the childhood leukemia. in this study, we evaluate the Quantitative human body dose prior to the treatment. The MCNPX simulation program evaluated by changing the material of the tissue compensators with imitation material of pediatric exposure in a virtual space. As a result, first, the average skin dose with the material of the tissue compensators of Plexiglass tissue compensators is 74.60 mGy/min, Al is 73.96 mGy/min, Cu is 72.26 mGy/min and Pb 67.90 mGy/min respectively. Second, regardless of the tissue compensators material that organ dose were thyroid, gentile, digestive system, brain, lungs, kidneys higher in order. Finally, the ideal distance between body compensator and the patient were 50 cm aparting each other. In conclusion, tissue compensators Al, Cu, Pb are able to replace of the currently used in Plexiglass materials.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.3
• /
• pp.1-7
• /
• 2006

The Primary type of swinging motion in human movement is that which is characteristic of a pendulum. The two types of pendulums are identified as simple and compound. A simple pendulum consist of a small body suspended by a relatively long cord. Its total mass is contained within the bob. The cord is not considered to have mass. A compound pendulum, on the other hand, is any pendulum such as the human body swinging by hands from a horizontal bar. Therefore a compound pendulum depicts important motions that are harmonic, periodic, and oscillatory. In this paper one discusses and compares two algorithms of Newton's method(F = m a) and Euler's method (M = $I{\times}{\alpha}$) in compound pendulum. Through exercise model such as human body with weight(m = 50 kg), body length(L = 1.5m), and center of gravity ($L_c$ = 0.4119L) from proximal end swinging by hands from a horizontal bar, one finds kinematic variables(angle displacement / velocity / acceleration), and simulates kinematic variables by changing body lengths and body mass. BSP by Clauser et al.(1969) & Chandler et al.(1975) is used to find moment of inertia of the compound pendulum. The radius of gyration about center of gravity (CoG) is $k_c\;=\;K_c{\times}L$ (단, k= radius of gyration, K= radius of gyration /segment length), and then moment of inertia about center of gravity(CoG) becomes $I_c\;=\;m\;k_c^2$. Finally, moment of inertia about Z-axis by parallel theorem becomes $I_o\;=\;I_c\;+\;m\;k^2$. The two-order ordinary differential equations of models are solved by ND function of numeric analysis method in Mathematica5.1. The results are as follows; First, The complexity of Newton's method is much more complex than that of Euler's method Second, one could be find kinematic variables according to changing body lengths(L = 1.3 / 1.7 m) and periods are increased by body length increment(L = 1.3 / 1.5 / 1.7 m). Third, one could be find that periods are not changing by means of changing mass(m = 50 / 55 / 60 kg). Conclusively, one is intended to meditate the possibility of applying a compound pendulum to sports(balling, golf, gymnastics and so on) necessary swinging motions. Further improvements to the study could be to apply Euler's method to real motions and one would be able to develop the simulator.

• The Journal of Korea Robotics Society
• /
• v.2 no.4
• /
• pp.297-303
• /
• 2007

In this paper, we discuss a service to give alarm in the case of emergency for the old and the weak by human behavior recognition in Intelligent Space. Our Intelligent Space consists of mobile robots, sensors and agents. And these components are connected to network framework. Agent analyzes data acquired from networked sensors and determines task of robots and a space to provide a service for humans. In our emergency alarm service, human behavior recognition service module analyzes accelerometer data obtained from body-attached human behavior sensing platform, and classifies into four basic human behavior such as walking, running, sitting and falling-down. For the old and the weak, falling-down behavior may bring about dangerous situations. On such an occasion, agent executes emergency alarm service immediately. And then a selected mobile robot approaches fallen person and sends images of the person to guardians. In this paper, we set up a scenario to verify the emergency alarm service in Intelligent Space, and show feasibility of the service from our simulation experiments.

• Korean Institute of Interior Design Journal
• /
• v.14 no.6 s.53
• /
• pp.112-119
• /
• 2005

Virtual reality(VR) is the technology that makes a user regard being in virtual space generated by computer as in the real world. Mainly, it has been studied about the three senses which are the sense of vision, touch and hearing in the five human senses. Through that, it is applied to the system making all the senses in the human body real. Even though the design idea of theater is brought to that of simulation theater, there are not many similarities between them and not general design rules yet. For making a better situation, in cooperation with a domestic company making a motion simulator for one or two person by itself, I have considered the minimum conditions and formations of the simulation theater being widely useful in the buildings of general commercial spaces from the environmental viewpoint, and basing on that facts I try to make some sorts of fundamental design types so that they are more available than those in the past. In this research, I have set the three types of simulation theater, the 50 seats of motion simulator for one person, the 20 seats of motion simulator and the 50 seats for two persons, in my researching range. Moreover, regarding the size of the simulation theater, I put the best specifications in order and also put them together, and then with making standards able to be reflected on the design plan, I have researched it for the purpose of the accumulation of skill in the construction of the special theater. Here, the design rule I suggested might be a design standard that it will be thought useful widely.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2654-2659
• /
• 2003

In this paper, we present biomimetic hopping strategy which is more human-like for legged robot through stiffness modulation. Stiffness value is calculated from the motion of body center of gravity. This method enable to reduce impact force on touch-down, adaption on ground stiffness change and height modulation. Simple selected models will be used to validate this method. For general model, singular perturbation is used for control and simulation using stiffness modulation is presented.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 1999.05a
• /
• pp.154-162
• /
• 1999

This paper introduces the research and development of automatic generation technology to develop the character agent. The R&D of this technology includes three major elements-body model generation, automatic motion generation and synthetic human generation. Main areas of application would be cyber space- 3D game, animation, virtual shopping, on line chatting, virtual education system, simulation and security system.