• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.707-710
• /
• 1996

During King Sejong's reign in early Chosen Dynasty, the Korean science had been in full bloom. Among the many splendid achievements of the period, though most of them are not extant, astronomical instruments and clocks made for equipping the Royal Observatory are taken as typical works that reflect the characteristics of the King's scientific projects and discussed in the view point that what and how much a well-planned drive and a future-oriented leader can accomplish.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.4 s.193
• /
• pp.109-114
• /
• 2007

The mobility (degree of freedom) of mechanisms can be regarded as independent coordinate to define its position. This concept is essential for kinematics, and for designing mechanisms in the practical point of view. Gruebler's equation has been applied to estimate the mobility using number of links and joints of a mechanism. In practical case, there are many types of mechanisms, which transfer motion by direct contact between two links. However, no exact kinematic definition has existed for the joint that the contact takes place in a mechanism. In this paper, a new concept of contact joint is defined and modified Gruebler's equation is suggested to calculate mobility of a mechanism with the joint. This concept would be useful in mechanism design because it will be possible to manage many contact mechanisms with kinematic exactness.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.15-20
• /
• 2005

We have achieved 180-degree angle of view performance using Super-PVA (S-PVA) technology first time in TFT-LCD industry. 82" full high definition ($1920{\times}1080$) TFT- LCD panel, the world's largest TFT-LCD, have been developed. In addition to the size breakthrough, this product achieves 600nits brightness, over 1200:1 contrast ratio, viewing angle free, 92% color gamut, and 8ms response time. Several key enabling technologies were developed to achieve these specifications, including two transistor direct driven independently controlled S-PVA subpixels, non even area ratio sub-pixels for optimal offaxis gamma, gate overlap driving for larger driving margin, new CCFL technology for higher color gamut, and advanced fabrication techniques including the use of Samsung's new $7^{th}$ generation line.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.31-35
• /
• 2005

A prerequisite for a wide market acceptance of 3D displays is the ability to switch between 3D and full resolution 2D. In this paper we present a robust and cost effective concept for an auto-stereoscopic switchable 2D/3D display. The display is based on an LCD panel, equipped with switchable LC-filled lenticular lenses. A demonstrator of this concept is made. We will discuss measurements and numerical simulations of the key optical characteristics of this display. The switching characteristics of LC-filled lenticular lenses are discussed and the overlap of the view distributions is introduced as a figure of merit for crosstalk. The 0.62 overlap in our present demonstrator design, gives an excellent 3D image quality, combined with a good depth impression.

• Journal of Information Display
• /
• v.11 no.2
• /
• pp.57-62
• /
• 2010

A method of characterizing time-sequential stereoscopic 3D displays based on the measurement of the temporal behavior of the systems vs. the grey levels is proposed. An Nvidia 3D vision kit with a 3D-ready SAMSUNG 2233RZ LCD display is characterized in the paper. OPTISCOPE SA especially designed for the precise measurements of the luminance and temporal behavior of LCD displays was used. The transmittance and response time of the shutter glasses was first evaluated. Then the grey-to-grey response times of the display were measured. The 2D and 3D behaviors of the display were then compared. Finally, the temporal behavior of the complete system was modeled, and the grey-level variations on one view were deduced as a function of the synchronization and level of the other eye. The main sources of imperfection were identified and quantified, and a full computation of the system performances was done.

• Journal of the Korea Safety Management & Science
• /
• v.6 no.4
• /
• pp.11-24
• /
• 2004

Recently occupational safety and health literatures begin to emphasize the influence of social, organizational or psychological context. Based on this research trend, this paper tried to review the relationship between safety climates and safety compliance. Based on the responses from 385 manufacturing workers, this paper reviewed the relationships among safety climates, safety motivation, and safety compliance. The results of statistical analysis showed that all safety climate factors(management involvement, leadership, safety training, precaution activities, safety system) have affirmative effects on safety motivation and safety compliance. Also, safety motivation appeared to have mediating effects on the relationship between 5 safety climate factors and safety compliance. Especially it appeared to have full mediating effects on the relationship between safety training/ safety system and safety compliance.

• Proceedings of the KSR Conference
• /
• 1998.05a
• /
• pp.361-368
• /
• 1998

Described in this paper is the result of a study on collision analysis of TGV-K using 1-dimensional model for crashworthy design. Crashworthy design of the front end is very important because majority of the impact energy (more than 70%) is absorbed by the crush of the front end when the train is collided with an obstacle like a tank lorry. Guideline for the crashworthy design can be described from the collision analysis of the whole train using a 1-dimensional model. Since the headstock of TGV-K is not designed in a crashworthy point of view, a conceptual design of the headstock to improve crashworthiness is suggested and evaluated using 1-dimensional collision analysis. The suggested design, which adopts an energy absorber and a crashworthy headstock, shows a good behaviour on the accident scenario of SNCF (collision at 110 km/hr against a movable rigid mass of 15 ton).

• Proceedings of the Safety Management and Science Conference
• /
• 2004.11a
• /
• pp.183-188
• /
• 2004

Recently occupational safety and health literatures begin to emphasize the influence of social, organizational or psychological context. Based on this research trend, this paper tried to review the relationship between safety climates and safety compliance. Based on the responses from 385 manufacturing workers, this paper reviewed the relationships among safety climates, safety motivation, and safety compliance. The results of statistical analysis showed that all safety climate factors(management involvement, leadership, safety training, precaution activities, safety system) have affirmative effects on safety motivation and safety compliance. Also, safety motivation appeared to have mediating effects on the relationship between 5 safety climate factors and safety compliance. Especially it appeared to have full mediating effects on the relationship between safety training/ safety system and safety compliance.

• Journal of the Optical Society of Korea
• /
• v.13 no.1
• /
• pp.131-138
• /
• 2009

The similarity between two groups of displaying methods is demonstrated in two ways, analytically and experimentally. A variety of layouts of the integral photography and display devices based on the point light source model is classified and analyzed in terms of projections and common/separate image planes. In particularly, the transformation matrix is found. Simulation experiments based on the image processing were performed. The layouts, analytical formulas, and experimental results show the similarity of both groups for several layouts.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.2 no.3
• /
• pp.321-329
• /
• 2013

A multilevel inverter employing a cascade transformer is proposed for a silent-discharge-tube ozone generating system. The proposed inverter consists of four full-bridge inverters and fourteen transformers which have a series-connected secondary. It can accurately control the amplitude of the output voltage; hereby, it improves a linear characteristic of the rate of ozone yielding. The power regulation characteristics and operational principle of the proposed system are explained from a practical point of view. High precision ozone generating performance of the proposed multilevel inverter is verified by computer-aided simulations and experiment results.