• Tribology and Lubricants
• /
• v.34 no.6
• /
• pp.300-306
• /
• 2018

In this study, the performance of foil thrust bearings was investigated by performing bearing take-off and load capacity tests, using an in-house designed and manufactured vertical bearing test rig. The mean take-off rotational speed and maximum load capacity of the bearing specimen were ~18,000 rpm and ~80 kPa, respectively. The vertical bearing test rig was observed to yield higher coefficients of friction and frictional torques than a horizontal bearing test rig under identical test conditions. This was a result of its structural characteristics, in that the bearing specimen is placed atop the thrust runner, which keeps it from being separated from the runner after the bearing take-off. In addition, bearing take-off was observed at a higher runner rotational speed as this structure keeps air from flowing between the top foil and runner surfaces, which requires a higher runner speed. The parallel alignment between the bearing specimen and runner surfaces can be maintained within a certain range more easily in a vertical test rig than in a horizontal test rig. Because of these advantages, Korean Industrial Standard, KS B 2060, recommends a vertical bearing test rig as the standard test device for foil thrust bearings.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.2
• /
• pp.99-109
• /
• 2013

In this paper, we propose a new system which captures real depth and color information from natural scene and implemented it. Based on it, we produced stereo and multiview images for 3-dimensional stereoscopic contents and introduced the production of a digital hologram which is considered to the next-generation image. The system consists of both a camera system for capturing images which correspond to RGB and depth images and softwares (SWs) for various image processings which consist of pre-processing such as rectification and calibration, 3D warping, and computer generated hologram (CGH). The camera system use a vertical rig with two paris of depth and RGB camera and a specially manufactured cold mirror which has the different transmittance according to wavelength for obtaining images with the same view point. The wavelength of our mirror is about 850nm. Each algorithm was implemented using C and C++ and the implemented system can be operated in real-time.

• Tribology and Lubricants
• /
• v.26 no.4
• /
• pp.224-229
• /
• 2010

A new test rig is presented to measure friction losses at journal bearings in a reciprocating compressor. This rig consists of a test bearing, torque sensor, driving motor and loading parts especially for vertical shaft. Friction losses are obtained by measuring torque between motor and test bearing. The experiments are carried out at several rotational speeds and temperatures. The test results are presented and discussed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.9 no.3
• /
• pp.204-209
• /
• 2003

The line-of-sight stabilization system is an equipment which is loaded on a vehicle and stabilizes the direction of the line-of-sight of the vision sensor to obtain a not-swayed image in the existence of external disturbances. To obtain accurate Euler angles and angular velocities simultaneously we usually need a control system which uses high-price inertial sensors including Vertical Gyro(VG) or Rate Integrating Gyro(RIG). In this paper, we design and implement a control system of a gimbal, which is a line-of-sight stabilization system using a low-cost mixed algorithm of a rate gyro and an accelerometer instead of a VG and a RIG. In the experiment where we laid the implemented line-of-sight stabilization system on the rate table. we can see the stabilized performance to external disturbances.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.839-844
• /
• 2007

In order to reduce resultant stress of the connection detail of longitudinal and rib and floor beam, in this study, the parameter studies for the reinforcement details as the bulk head and the vertical rib were preformed with FE analysis. As the result, it was shown that reinforcement detail with the bulk head plate in longitudinal rig reduced generally the principal stress at the connection detail, but the stress concentration of the weld toe parts occurring fatigue crack increased. However, it was known that the reinforcement detail with the vertical rib in the rib is more effective than the bulk head plate of the reduction stress concentration in the weld toe parts.

• Journal of Broadcast Engineering
• /
• v.18 no.2
• /
• pp.149-158
• /
• 2013

In this paper, we propose a new system which can generate digital holograms for natural color scene. The system consists of both a camera system for capturing images and softwares(SWs) for various image processings. The camera system uses a vertical rig with a depth and a RGB camera and a cold mirror which has the different transmittance according to wavelength for obtaining images with the same view point. The S/W is composed by the engines for processing and servicing the captured images and computer-generated hologram (CGH) for generating digital holograms using general-purpose computing on graphics processing unit (GPGPU). Each algorithm was implemented using C/C++ and CUDA languages, and all engines were integrated in LabView environment. The proposed system can generate 10 digital holographic frames per second using about 6K light sources.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.8 s.251
• /
• pp.764-771
• /
• 2006

Knowledge of ground thermal properties is most important for the proper design of large BHE(borehole heat exchanger) systems. Thermal response tests with mobile measurement devices were first introduced in Sweden and USA in 1995. Thermal response tests have so far been used primarily for in insitu determination of design data for BHE systems, but also for evaluation of grout material, heat exchanger types and ground water effects. The main purpose has been to determine insitu values of effective ground thermal conductivity, including the effect of ground-water flow and natural convection in the boreholes. Test rig is set up on a small trailer, and contains a circulation pump, a heater, temperature sensors and a data logger for recording the temperature data. A constant heat power is injected into the borehole through the pipe system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance.

• Wind and Structures
• /
• v.13 no.5
• /
• pp.413-431
• /
• 2010

The focus of this article is on the assessment of vertical wind vector components and their aerodynamic impact on lattice framework, specifically two distinct sections of a guyed transmission tower. Thunderstorm winds, notably very localized events such as convective downdrafts (including downbursts) and tornadoes, result in a different load on a tower's structural system in terms of magnitude and spatial distribution when compared to horizontal synoptic winds. Findings of previous model-scale experiments are outlined and their results considered for the development of a testing rig that allows for rotation about multiple body axes through a series of wind tunnel tests. Experimental results for the wind loads on two unique experimental models are presented and the difference in behaviour discussed. For a model cross arm with a solidity ratio of approximately 30%, the drag load was increased by 14% when at a pitch angle of $20^{\circ}$. Although the effects of rotation about the vertical body axis, or the traditional 'angle of attack', are recognized by design codes as being significant, provisions for vertical winds are absent from each set of wind loading specifications examined. The inclusion of a factor to relate winds with a vertical component to the horizontal speed is evaluated as a vertical wind factor applicable to load calculations. Member complexity and asymmetric geometry often complicate the use of lattice wind loading provisions, which is a challenge that extends to future studies and codification. Nevertheless, the present work is intended to establish a basis for such studies.

• Journal of Broadcast Engineering
• /
• v.19 no.5
• /
• pp.590-605
• /
• 2014

The purpose of this paper is to propose a service system for a digital hologram video, which has not been published yet. This system assumes the existing service framework for 2-dimensional or 3-dimensional image/video, which includes data acquisition, processing, transmission, reception, and reconstruction. This system includes acquisition of color and depth image pairs from a image acquisition system with vertical rigs, rectification of acquired image pairs and generating digital hologram. Also it is designed to reduce the CGH (computer-generated hologram) generation time to 1/3. It also includes some additional and optional functions such as watermarking, compression, and encryption.

• 한국연소학회:학술대회논문집
• /
• 2012.11a
• /
• pp.339-340
• /
• 2012

The purpose of this study is to analyse, the basic parameters through experimentally and with CFD modelling, internal recirculation of the flameless combustion of natural gas. The test rig is made up of a vertical combustion chamber of circle cross section. The inner dimensions of the chamber are $0.2m{\times}1m$ (diameter x height). And CFD simulations of the combustion chamber have been performed using FLUENT 14.0. Some results of this study present the basic parameters and data of flameless combustion.