• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.665-672
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• 2002

This paper deals with the human-interactive actions of a quadruped robot by using Genetic Algorithm. In case we have to work out the designed plan under the special environments, our robot will be required to have walking capability, and patterns with legs, which are designed like gaits of insect, dog and human. Our quadruped robot (called SERO) is capable of not only the basic actions operated with sensors and actuators but also the various advanced actions including walking trajectories, which are generated by Genetic Algorithm. In this paper, the body and the controller structures are proposed and kinematics analysis are performed. All of the suggested motions of SERO are generated by PC simulation and implemented in real environment successfully.

• Fibers and Polymers
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• v.4 no.4
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• pp.169-175
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• 2003

A simulation system for versatile garment drape has been developed. Using this system, the shape of a garment can be simulated in consideration of fabric physical properties as well as the interaction between fabrics and other objects. Each fabric piece in a garment is modeled using a geometrically constrained particle system and its behavior is calculated from an implicit numerical integration algorithm in a relatively short time. The system consists of three modules including a preprocessor for the preparation of fabric patterns and external objects, a postprocessor for the results of three-dimensional visualization, and a drape simulation engine. It can be used for the design process of textile goods, garments, furniture, or upholsteries.

• Journal of Sensor Science and Technology
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• v.29 no.1
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• pp.33-39
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• 2020

Typically, photoacoustic images are obtained in water or gelatin because the impedance of these mediums is similar to that of the human body. However, these acoustic mediums can have an additional mass effect that changes the resonance frequency of the transducer. The acoustic radiation impedance in air is negligible because it is very small compared to that of the transducer. However, the high acoustic impedance of mediums such as the human body and water is quite large compared to that of air, making it difficult to ignore. Specifically, in a case where the equivalent mass is very small, such as with a micro-machined ultrasound transducer, the additional mass effects of the acoustic medium should be considered for an accurate resonance frequency design. In this study, a piezoelectric micro-machined ultrasonic transducer (pMUT) was designed to have a resonance frequency of 10 MHz in the acoustic medium of water, which has similar impedance as the human body. At that time, the resonance frequency of the pMUT in air was calculated at 15.2 MHz. When measuring the center displacement of the manufactured pMUT using a laser vibrometer, the resonance frequencies were measured as 14.3-15.1 MHz, which is consistent with the finite element method (FEM) simulation results. Finally, photoacoustic images of human hair samples were successfully obtained using the fabricated pMUT.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.277-290
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• 1999

A simulation using the finite-difference time-domain method to analyze the electromagnetic interactions between a cellular phone and the human body was conducted, and a synthesis of a bone-equivalent material to make a human head phantom was performed. A test model of the cellular phone was fabricated to measure its reflection coefficient and radiation pattern in the free space. Various effects of the human body on the characteristics of the phone, such as input impedance, reflection coefficient, radiation pattern, and radiation efficiency are analyzed as the distance between the head and the phone antenna varies. When the phone was operated close to the head, the resonant frequency of the antenna decreased by up to 12%. With the output power of 0.6W, as long as the distance was larger than 30mm, the 1-g averaged peak SAR was below the ANSI/IEEE safety guideline, 1.6 W/kg. To synthesize the bone-equivalent material, an epoxy with hardener and a graphite powder were used as basis ingredients, and a small amount of a conducting epoxy was added to control the conductivity of the material. A material having a relative permittivity of 18.04 and a conductivity of 0.347, which are close to those of the bone at 850 MHz, was synthesized.

• Journal of the Korea Computer Graphics Society
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• v.2 no.1
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• pp.48-60
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• 1996

This paper present a new technique for doing realistic computer animation. The method is based on forward dynamic simulation and nonlinear problem solving (parameter optimization) technique. Objects are modelled physically and simulated faithfully while satisfying kinematic and geometric constraints. This forward dynamic simulation gives us very realistic motions especially for non-voluntary motions. Then we extend simulation technique to do animation using parameter optimization. The basic idea is to add motion control over the entire animation. The motion control is finding optimal solutions while satisfying user's animation goals. We provide two different animation technique; one is for rigid body without joint actuators and the other is for rigid body with linear joint actuators. To achieve motion control, we convert single simulation to single nonliner function evaluation while either setting initial conditions as variables for the function or allocating control variables in terms of time. This method is presented with two animation examples: dice-magic and human stand-up.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.981-987
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• 2009

Recently, the study on wireless body area network for providing ubiquitous healthcare services has been actively done, including the standardization of the IEEE and others. Wireless body area network is usually configured in tree format using multi-hop communication mode due to the power limitation and the characteristics of human body. In this case, differently from existing sensor network, the wireless body area network tends to be disconnected due to the frequent movement of human body. The number of connections which can be supported at each node has some limitations due to the constraint imposed on power consumption. In this paper, we have proposed a heuristic algorithm for optimal selection of parent node with guaranteed QoS for a disconnected node, which considers the priority on packet transmission. Simulation has been performed to evaluate the performance of the proposed algorithm.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.142-148
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• 2011

Because currently available wireless technologies are not appropriate for wireless body area networks (WBANs), the IEEE 802.15.6 standard was introduced by the IEEE 802.15.6 Task Group to satisfy all the requirements for a monitoring system that operates on, in, or around the human body. In this work, we develop an analytical model for evaluating the performance of an IEEE 802.15.6-based WBAN under saturation condition and a noisy channel. We employ a three-dimensional Markov chain to model the backoff procedure as specified in the standard. Probability generating functions (PGFs) are used to compute the performance descriptors of the network. The results obtained from the analytical model are validated by simulation results. Our results indicate that under saturation condition, the medium is accessed by the highest user priority nodes at the vast majority of time while the other nodes are starving.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.69.5-69
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• 2001

Computer simulations are widely used to analyze passenger safety in traffic accidents. ATB(articulated total body) is a computer simulation model developed to predict gross human body response to such dynamic environments as vehicle crashes and pilot ejections. ATB, whose code is open, has high flexibility and application capability that users can easily insert defined modules and functions. ATB is, however, inconvenient as it was coded in FORTRAN and it needs a formatted input file. Moreover, it takes much time to make input files and to modify coding errors. This study aims to increase user friendliness by adding a preprocessor program, WINATB(WiNdow ATB), to the conventional ATB. WINATB programmed in Visual C++ and OpenGL uses ATB IV as a dynamic solver ...

• Journal of Magnetics
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• v.21 no.3
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• pp.442-449
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• 2016

In this paper, an effective numerical analysis method is proposed for calculating dosimetry of the wireless power transfer system operating low-frequency ranges. The finite-difference time-domain (FDTD) method is widely used to analyze bio-electromagnetic field problems, which require high resolution, such as a heterogeneous whole-body voxel human model. However, applying the standard method in the low-frequency band incurs an inordinate number of time steps. We overcome this problem by proposing a modified finite-difference time-domain method which utilizes a quasi-static approximation with the surface equivalence theorem. The analysis results of the simple model by using proposed method are in good agreement with those from a commercial electromagnetic simulator. A simulation of the induced electric fields in a human head voxel model exposed to a wireless power transmission system provides a realistic example of an application of the proposed method. The simulation results of the realistic human model with the proposed method are verified by comparing it with the conventional FDTD method.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1338-1339
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• 2008

In this paper, charging part by basic from Andrew's body model research to second a danger have affect on remaining and rehabilitation humans in space under water. The construction of a circuit make to Andrew's body model. It compare that voltages measure a hand, a breast, a groin and electric currents measure an arm, a breast, a leg with safety a limit of body through an electric current. Out of result, it research that magnitude and wave of body passing an electric current give the effect to the heart control a signal and it have affect on direct the ventricle of the heart in detail motion. A thing of this sort get through to the simulation by the ATP-Draw program. The results from above, it is publish one's research work with safety a limit electric angle take measurement of resistance a body in under water and to the voltage and electric current passing each parts.