• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1996.06b
• /
• pp.13-17
• /
• 1996

This paper presents animation techniques and issues involved in virtual environments where the participants interact with each other through a network. The state of the participant should be recognized at each local site, and broadcast to the other sites. Because information exchange is minimal, animation techniques are applied to convert the incoming low DOF parameters into high DOF joint angles that completely determine the configuration of the agents at each frame. As a case study, a software system VRLOCO is introduced, which has been developed by the author over the last five years. From a simple stream of body center positions, VRLOCO generates realistic curved path human locomotion in real-time. Based on the heading direction and speed, the locomotion automatically switches among five different primitives: walking, running, lateral stepping, backward stepping, and turnaround. The techniques presented here proved robust and faithful: the algorithm is not sensitive to the noise in the data, and the resulting animation conforms well with the original data.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.667-672
• /
• 2000

The Characteristics of the conical vortices on the roof surface of a low-rise building has been investigated by using a PIV(Particle Image Velocimerty) technique. The scaled model of TTU building with 1:92 scaling ratio was used. The Reynolds number based on the free stream velocity and the length of the model was $1.96{\times}10^5$. When the angle of attack for the building model is $45^{\circ}$, the conical vortices are occurred symmetrically and the center of vortices are changed with respect to the angle of the approaching flow. The rotating direction of the conical vortices found to be counter-rotating. The secondary vortex motions are investigated using the instantaneous flow field data.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.2
• /
• pp.84-91
• /
• 2001

To investigate the aerodynamic characteristics of the on a road vehicle, experimenrs were performed at an Atmospheric Boundary Layer Wind Tunnel. The scaled model of an automobile with 1 : 3 scaling ratio was used. The Reynolds number based on the free stream velocity and model length was $7.93{\times}10^5$. The influence of crosswind to the stability of automobile was investigated by the pressure distribution measurements and flow visualization studies. with the variation of the angle of attack, the change in pressure coefficient depends highly on the flow separation regimes. The experimental and numerical results are compared and found to be in good agreements.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.4
• /
• pp.219-227
• /
• 1998

This paper describes the fuel spray characteristics of gasoline port injectors such as the breakup procedures of liquid fuel, breakup and extinction behaviors of fuel spray at nozzle tip, time history of SMD and velocity distribution of fuel spray in the direction of fuel stream. Pintle-type gasoline fuel injector was used to analyze mentioned spray characteristics. In order to visualize the fuel spray behaviors and to measure the droplet mean diameter and velocities of spray droplets, the Schlieren method, digital image processing and auto-correlation PIV were applied in this study. In addition, the spray characteristics according to the variation of time were considered. The results of fuel spray show that the liquid sheet breakup starts at 10mm downstream actively. The flying time is approximately 4msec between 50mm and 80mm down the nozzle tip. Also, SMD of fuel spray, the number of droplets and fuel velocity distribution at each point of downstream are discussed.

• Korean Journal of Computational Design and Engineering
• /
• v.8 no.3
• /
• pp.150-156
• /
• 2003

Direct Metal Deposition (DMD) is a new additive process producing three-dimensional metal components or tools directly from CAD data, which aims to take mold making and metalworking in an entirely new direction. It is the blending of five common technologies: lasers, CAD, CAM, sensors and materials. In the resulting process, alternatively called laser cladding, an industrial laser is used to locally heat a spot on a tool-steel work piece or platform, forming a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the metal pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is eventually built line-by-line, one layer at a time. DMD produces improved material properties in less time and at a lower cost than is possible with traditional fabrication technologies.

• Journal of Digital Contents Society
• /
• v.11 no.4
• /
• pp.495-501
• /
• 2010

The main stream of existing game market was console and PC-based games. In these days mobile game industry extends its boundary according to the advance of mobile device capability. Especially, smart phones, known as computers in hands, accelerate the expansion of mobile game market. This paper analyzes the characteristics and the current status of mobile game market. Based on this analysis, future directions for mobile game market are given.

• Journal of Mechanical Science and Technology
• /
• v.17 no.8
• /
• pp.1203-1210
• /
• 2003

Emission of ultrasonic vibration to turbulent flow promotes the turbulence generation due to the resonantly oscillating pressure field and thereby induced cavitation. In addition, ultrasonic vibration is well transmitted through water and not dissipated easily so that the micro-bubbles involved in the fluid induce the gaseous cavitation if the bubbles are resonated with the ultrasonic field. In the present study, we found through LDV measurement that the gaseous cavitation induced by ultrasonic vibration to CO$_2$saturated water flow in the rectangular cross-sectioned straight duct enhances turbulence much more than the case of non-ultrasonic or normal ultrasonic conditions without gaseous cavitation. We also found that the fluctuating velocity component induced by emitting the ultrasonic vibration in normal direction of a rectangular channel flow can be redistributed to stream-wise component by the agitation of gaseous cavitation.

• Proceedings of the Korean Institute of Interior Design Conference
• /
• 2005.05a
• /
• pp.126-131
• /
• 2005

As our domestic Espresso Coffee Shops are in pursuit of professionalization and various coffee tastes, their sales will have been on increase. Now coffee market is getting more mature. Reflecting sensitivity of 20 to 30 generations, the domestic coffee shops provide them with best space for rest and conversation with stream of industralization and professionalization of the contemporary society. Based on such a situation, our research institute aims at studying how the interior designs put influence on marketing. Among the domestic franchise coffee shops, we will have researched Rosebud, Starbugs, Davinci which have more 50 chain stores throughout the country, This study aims to suggest a direction for interior design of brand coffee shop by analyzing brand coffee shops and style that customers prefer.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.2
• /
• pp.1-8
• /
• 1997

Nature preservatio has been a main stream trend as the purpose and meaning of world's national park management since the definition of a national park was first adopted at the IUCN meeting in New Delhi in 1969. However, Korea's national parks have been managed in a direction opposed to that of the world trend. The internationally accepted meaning defines a national park is the most important system for nature conservation, where an ecosystem must be preserved in as much of a natural state as possible. It also defines a national park is a place where only the minimum amount of human intervention is allowed. The role of tourism, which was initially expected to play a significant role in national parks, has been reduced to the extent where tourism in national parks is allowed only to the point where conflicts arising from local socio-economic interests tied up to the tourism can be dealt with. From this perspective, Korea's national parks are being challenged to establish new relationship between mean and nature and to develop management based on ethical grounds for future generations.

• 한국가시화정보학회:학술대회논문집
• /
• 2006.12a
• /
• pp.36-41
• /
• 2006

Reverse flow (i.e. flow in the direction opposite to the free stream) inside a channel occurs when an obstruction is placed at certain positions near the near to the channel, placed in another wider channel. In this paper the reverse flow in a duct (diameter D) with an obstruction at the front (which is a disc), is investigated using PIV. The gap g between the obstruction and the entry to the duct is systematically varied and it is found that maximum reverse flow occurs at a g/D value of 0.5. The flow is stagnant around g/D of 1.25 and forward flow occurs for g/D values of 1.5 and above.