• Journal of Korea Game Society
• /
• v.17 no.3
• /
• pp.53-62
• /
• 2017

VR content manipulation equipment is not easy for individuals to access because it requires high prices. Especially, in the case of a system for tracking the motion of the user among the VR contents, a separate optical sensor device using an infrared camera is generally used. The disadvantage of the optical sensor equipment is that the measurable range is dependent on the measurement direction when tracking the rotation motion when using only a single device. In order to solve the above problems, this paper shows that the inertial sensor of the smartphone, which is generally owned by the public, can track the rotational motion of the user regardless of the measurement direction . The system using the LeapMotion is used as the reference system, and the system using the smart phone is defined as the evaluation system, and the usability of the evaluation system is verified by comparing the user satisfaction of the two systems.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.336-340
• /
• 1997

This paper is a study about motor technic of motion and feedforward control in order to shape cutting control on the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control, shape error generated by the position command delay is minimized by using the acceleration/deceleration time constant after the interpolation. The study was verified to optimization of motion control on experiments of a vertical machining center of the machine tool.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.151-155
• /
• 1996

In this paper, the continuous motion of a quadrupedal walking machine was studied. The motion planning which is able a walking machine body to precisely follow a three-dimensional curve was developed. A three-dimensional curve was designed based on Bezier curve and obstacle avoidance considerations. Due to the arbitrary motion direction during walking, special strategies of gaits were developed to ensure positive stability. The gait strategies were based on wave and wave-crab gait.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.12C
• /
• pp.1209-1216
• /
• 2003

The transcoding is needed to modify the bit rate of the video bitstream in accordance with the bandwidth of a variety of channels in order to provide users with a realtime multimedia service and more stable and credible VOD(Video On Demand) service on various wire/wireless network. This paper suggests how to guarantee the video quality in the transcoding process, taking the activity and direction of the macroblock into consideration, thereby reducing the calculation. The threshold of the macroblock's activity and direction is applicable to the different videos, with the DCT coefficients from the intermediate data in the decoding process. Moreover, the suggested video transcoding algorism enables us to maintain the proper video quality and reduce the calculation through the video bit rate change experiment in H.263 environment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.2
• /
• pp.131-136
• /
• 2008

The transducer for multi-directionally movable ultrasonic motor having lambda shaped vibrators has been proposed and designed. The two branches cross at a right angle with each other at the tip. FEM analyses of lambda shaped transducer were carried out to find vibration modes for ultrasonic motor. The lambda shaped transducer has one symmetric mode and two anti-symmetric modes. The symmetric mode generates the normal direction motion of the tip. The lateral and vertical direction motion of the tip are excited by two anti-symmetric modes. The normal and lateral direction motions made an lateral elliptic trajectory. And the normal and vertical direction motions made an vertical elliptic trajectory normal to previous one. The transducer with 1 mm in thickness and 25 mm in length has been fabricated and evaluated. The resonance frequencies of the transducer was 32 kHz and 103 kHz. The tangential and vertical vibration displacement of the transducer having the lateral elliptic trajectory were $1.5{\mu}m\;and\;1.1{\mu}m$, respectively at the driving voltage of 100 Vpp and frequency of 32 kHz and 103 kHz. And the tangential and vertical vibration displacement of the transducer having the vertical elliptic trajectory were $0.4{\mu}m\;and\;0.2{\mu}m$, respectively at the same driving condition.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.1
• /
• pp.151-156
• /
• 2021

The speed and direction of the earth's fluid motion is measured by a remote sensing method using electromagnetic waves. Using UHF radar and GPS Sonde, the vertical profile of fluid velocity was calculated by the Euler measurement method and the Lagrange measurement method, respectively. Since the wind direction, which is the direction of motion of the atmosphere, is indicated in the direction of the wind blowing, and a circular value of 0° - 360° is used, it is necessary to pay attention to statistical analysis. Errors caused by calculation conditions are provided, and the corrected accuracy of comparison results is improved by 400%.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.4
• /
• pp.341-348
• /
• 2017

This study examined the effects of the location and direction of the scolioti curve on postural balance in patients with idiopathic scoliosis. Fifteen subjects were divided into three groups: right thoracic curve group, left lumbar curve group, and double curve group. The dynamic trunk motion (angle variation in the lumbar, thoracolumbar, lower thoracic and upper thoracic region) and plantar pressure distribution (maximum force and peak pressure) were assessed using an ultrasound-based motion analysis system and Emed-at platform system. From the results, it was confirmed that patients with idiopathic scoliosis showed postural imbalance with an increased angle and pressure asymmetry according to the location and direction of the scoliotic curve for dynamic trunk motion and plantar pressure distribution. In addition, there were differences in the postural balance pattern between the single curve and double curve groups. Further studies for developing a rehabilitation training device will be conducted to improve the postural control ability and trunk balance as well as treat scoliosis based on the results of this study.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.8 s.173
• /
• pp.57-63
• /
• 2005

Development of a locomotive mechanism fer the capsule type endoscopes will largely enhance the ability to diagnose disease of digestive organs. In connection with it, most of researches have focused on an installable locomotive mechanism in the capsule. In this paper, it is introduced that the movement of a capsule type endoscope in digestive organ can be manipulated by magnetic force produced outside human body. Since the magnetic force is provided by permanent magnets, no additional power supply to the capsule is required. Using a robotic manipulator for locating the external magnet, the capsule motion control system can cover the whole human digestive organs. This study is particularly concentrated on dither motion effect to improve the mobility of capsule type endoscope. It was experimentally found out that the friction coefficient between the capsule and digestive organ can be remarkably reduced by superposing yawing or rolling dither motion on the translatory motion. In this paper, the experimental results obtained with the direction, amplitude and frequency of sinusoidal dither motion changed is reported.

• International Journal of Precision Engineering and Manufacturing
• /
• v.7 no.2
• /
• pp.60-65
• /
• 2006

A vibrational model of powder transfer equipment based on the lumped parameter method was developed, in which the operating motion consists of surging, bouncing, and pitching. After decoupling the equation of motion, the vibrational excitation source of the pitching motion was removed. So the designers are able to plan the optimum design to adjust the motion trajectory of the powder transfer equipment. That is, a procedure to adjust the motion trajectory of powder transfer equipment by changing design specifications such as the installation position, the direction of the motor, the driving speed, the mass unbalance, the stiffness coefficient, and the installation position of the support spring, is presented in this paper. The powder transfer equipment manufactured according to the results of this study did not suffer fatigue destruction, since the maximum stress on the basket structure was sufficiently small.

• Journal of KSNVE
• /
• v.7 no.5
• /
• pp.765-772
• /
• 1997

This paper presents the swing motion analysis of the container crane headblock with the passive control device using hydraulic motors and anti-swing ropes. The device hauls at the headblock to opposite direction of its swing motion using the tension difference between anti-swing ropes connected to the headblock. To consider this control mechanism, the headblock is modelled as the rigid bar suspended by two hoist ropes at the overhead trolley and its non-linear equation of motion is derived using Lagrange's equation. Some numerical experiments using the equation are carried out to investigate the swing motion characteristics of the headblock under the variation of geometric relation among the cargo handling components and to evaluate the performance of the anti-swing device.