• Journal of the Semiconductor & Display Technology
• /
• v.3 no.4
• /
• pp.1-4
• /
• 2004

21세기에 접어들면서 Digital시험방송의 시작과 다양한 Contents의 유입으로 평판디스플레이 (Flat Panel Display)에 관한 관심과 수요가 증가하고 있다. 이 중 PDP는 90년대 후반부터 양산 및 개발을 시작하여 현재는 40 inch에서 60 inch 화면 크기의 제품을 시장에서 구입할 수 있으며, 03년도에는 80 inch 크기의 Proto-type Model을 공개한 바 있다. PDP는 40 inch 이상의 대면적 구현이 용이하다는 점, CRT와 동등 수준의 화상 구현이 가능하다는 점, 제조공법이 간단하고 제조원가가 저렴하다는 점 등을 특징으로 시장을 확대하고 있으나, 좀 더 대중적인 디스플레이가 되기 위해서는 고휘도 및 고효율화, 화질개선 그리고 저가격화 등과 같은 과제를 해결하여야 한다. 본 논문에서는 PDP의 개발역사 및 시장현황, 구조 및 구동 방법 그리고 해결과제 및 전망에 대해서 포괄적으로 살펴보기로 한다.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2369-2374
• /
• 2008

In the precision hot plate for wafer processing, the temperature uniformity of upper plate surface is one of the key factors affecting the quality of wafers. Precision hot plates require temperature variations less than ${\pm}1.5%$ during heating to $120^{\circ}C$. In this study, we have manufactured the flat plate heat pipe hot chuck of circle type(300mm) and investigated the operating characteristics of flat plate heat pipe hot chuck experimentally. Various liquids(aceton, FC-40, water) were used as the working fluid and charging ratio was changed($14{\sim}36\;vol.%$). Several cases were tested to improve temperature uniformity. Major working fluid to be investigated was water. Using water, various parameters such as charging ratio, wafer operation on-off time, different working fluids. In case of water, the temperature uniformity was ${\pm}1.5%$, response time of wafer were investigated.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.1
• /
• pp.54-59
• /
• 1996

As the current shape of SRM is of pulse type and changed by the motor parameters and drive conditions, the influences on the drive efficiency by control method are more than other types of motors. In this paper, a proper excitation condition to drive a SRM with high efficiency is proposed and tested. It is derived from the conditions that the phase current of a SRM is to be flat-topped at various drive. The saturation effect of magnetic circuit is accounted for more accurate analysis. Experimental tests are executed to verify the proposed excitation method. This drive system is easy to commutate and also advantageous in reducing torque ripple. (author). 6 refs., 10 figs., 1 tab.

• IE interfaces
• /
• v.11 no.2
• /
• pp.107-117
• /
• 1998

This paper presents a useful method of registration in manufacturing of shadow color mask for cathode ray tubes of the FTM (Flat Tension Mask) type, wherein the shadow mask and front panel are interchangeable when mask-panels are assembled, which is called ICM system. Theoretical analysis and alignment process are presented. The pattern of mask aperture is registered with a screen pattern of corresponding geometry of the panel in flat tension mask tube. Registration accuracy of panel and mask affects the purity of color cathode ray tube concerned with mislanding. It tries to minimize the misregistration caused by variances, which are mechanical error, mask stretching position error, restrictive number of fiducial point, etc.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.37-38
• /
• 2023

The purpose of this study is to manufacture mortars incorporating oyster shells and install them in the form of shaped, shaped butt joints, and flat boards to see what difference there is in the back temperature depending on the joint method and the type of installation. Based on the fact that similar backside temperatures were measured regardless of the presence or absence of a joint It is judged that the joint will not affect the backside temperature if it is constructed closely, In the case of ㄱ shaped, it is believed that the backside temperature higher than the backside temperature of the flat board was measured because heat accumulates on the backside during heating.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1366-1371
• /
• 2008

Four simulation models of plastic plate heat exchangers are designed and simulated. The flat plate type heat exchanger is designed as the reference model in order to evaluate how much thermal performance increases. The turbulence promoter type heat exchanger is fabricated with cylindrical-type vortex generators and rib-type turbulence promoters. The corrugate type is obtained from the conventional stainless steel compact heat exchangers, which are called the herringbone-type compact heat exchangers. The dimple type heat exchanger has a number of dimples on its surface. In this study, the flow and heat transfer characteristics of the plastic plate heat exchanger are investigated using numerical simulation and compared with experimental results. The flows are assumed as a three-dimensional, incompressible and turbulent model. The standard k-$\varepsilon$ model is used as the turbulent flow modeling, the SIMPLE algorithm is used to treat the coupling between pressure and velocity, and first order upwind scheme is used for discretization of momentum, turbulent and energy. The computational analysis and experimental results both show that the friction coefficient and Nu number is highest in the corrugate type.

• Journal of the Korean Home Economics Association
• /
• v.40 no.10
• /
• pp.231-241
• /
• 2002

This study is for research of relationship between shoes wearing by adult woman and foot type. The research was made through questionnaire sheets of general matters (age, body weight, height & occupation) and shoes wearing status (hill height, toe shape, wearing time) of 216 adult women reside in the metropolitan zone and the foot type was classified from foot measurement and the relationship between shoes wearing and foot type was analyzed. According to the result of analysis it is as follows : 1) In the shoes type prefer for they prefer for lower hill as more ages and were preferring shoes with higher hill as the taller women. 2) The instep height is lower and medial foot angle was increased as their ages are more. Majority of foot type was appeared with standard type and the broad type was indicated more by age of 20s. The classification by toe the square type was indicated by majority and in the age of 30-40s the egyptian type was more 3) As the age and weight get increased he height of arch become lower and indicated to transit to flat-foot. That is to say they prefer for round toe in case of fiat-foot, and for square toe in case of normal and, choice of shoe toe shape it indicated by more impact by the height of arch rather than toe length.

• Applied Chemistry for Engineering
• /
• v.27 no.1
• /
• pp.101-109
• /
• 2016

The purpose of this research was to develop a flat panel display device's glass etchant which can replace hydrofluoric acid. The glass etchant was composed of 18~19% wt% of ammonium hydrogen fluoride, 24~25 wt% of sulfuric acid, 45~46 wt% of water, 4~5 wt% of sulfate and 7~8 wt% of fluoro-silicate. By replenishing the etchant which has the amount of 5% of initial solution's mass, it was possible to reuse the etchant continuously. The developed etchant showed $5{\mu}m/min$ of etching rate at $30^{\circ}C$. The reusable etchant, with replenishing 5% of initial etchant mass showed the stable etching rate, which has the deviation of less than $0.1{\mu}m/min$ etching rate. The glass surface of flat panel display device created from our etching process was in good condition with any defects such as pin hole and dimple.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.940-947
• /
• 2018

The purpose of this study was to obtain data to support applied motions of bench press and to provide basic data for the efficient execution of the exercise by analyzing muscular activation through measuring electromyogram of pectoralis major and erector spinae when flat bench pressing with feet on the ground versus feet on the bench. For this study, 4 amateur bodybuilders and 2 health trainers were chosen as subjects. Surface electrodes were attached on the measuring muscles; pectoralis major and erector spinae. Motion phases were defined for the flat bench press and each subject, with a 10RM load, performed a set with feet on the ground and another set with feet on the bench. Data was analyzed in SPSS 20.0 and the following results were obtained. The placement of the feet did not affect the muscular activation of the pectoralis major during the flat bench press. however, the muscular activation of the erector spinae was different between the two positions.

• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.5
• /
• pp.396-403
• /
• 2011

The concept of an air lubrication has long been an object of attention since it can be utilized to reduce the frictional resistance, and what is more, it is eco-friendly. The present study examines the basic characteristics of an air cavity with intention of applying the air lubrication technology to the reduction of the resistance of a ship without excessive power increment. For the purpose, an air cavity was created at the bottom of a flat plate by injecting air behind a backward step and the hydrodynamic properties of the air cavity and the surrounding flow has been investigated experimentally and numerically. The influence of the step height and the air flow rate have been more carefully studied since they are presumed to be the main parameters affecting the characteristics of an air cavity. The results indicates that the shapes of the air cavities attached on the flat plate become "U" or "V" type depending on the incoming flow velocity and air flow rate. The study also confirms that the length of the air cavity increases with increase in air flow rate but there is a certain critical limit in the flow rate above which increase in the air cavity length is no more evident.