• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.871-874
• /
• 2003

The T-5 Lamps developed in 1996 is the high efficiency fluorescent lamps, the lamps voltage is high, and the lamps current small because the lamps are slender tube of 16mm diameter. And so, the electrical characteristics of the Ballast for the lamps are different from of the Ballast for T-10 or T-8 lamps. Therefore, the know-how of the exclusive Ballast for the T-5 fluorescent lamps should be as soon as possible. We described the electrical and optical characteristics of the Electronic Ballast for T-5 Circular Fluorescent lamps. The developed Electronic dimming Ballast for T-5 Circular Fluorescent lamps has the 45% energy saving effects than the T-10 lamps. And it has the promotion of the THD less than 10%, CF less than 1.5%, Flickering less than 5% and 99% power factor. And it is available for two T-5 Circular fluorescent Lamps dimming, 22W and 40W.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.2
• /
• pp.137-140
• /
• 2021

High dynamic range (HDR) technology has been drawing attention in the field of imaging and consumer entertainment. As tools for capturing and creating HDR contents, encoding, and transmission evolve to support HDR formats, various display capabilities are being developed and increased. Hence, there is need for remapping native HDR imagery for display on lower quality legacy standard dynamic range (SDR) displays. This operation is referred to as tone mapping. In this paper, we present a sectional tone mapping method by Lenzen, and expand upon a tone mapping approach to improve temporal stability while maintaining picture quality. Compared to the existing block-based sectional tone mapping, our method uses the edge awareness-based tone mapping. We estimate the performance of the objective metric on temporal flickering. The experimental result shows that the algorithm maintains a smoother relationship between the output luminance values, and this reveals success in reducing halos and improving temporal stability with adopted edge aware filtering.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.4
• /
• pp.56-62
• /
• 2010

Auto-exposure control automatically calculates and adjusts the exposure for consecutive input image. Recently, this is usually controlled by the sensor gain, however, unsuitable control causes oscillation of luminance for sonsecutive input images, called as flickering. Also, in mobile phone cameras, only simple information, such as the average luminance value, can be utilized due to coarse performance. Therefore, this paper presents a new real-time AE control method using a Look Up Table(LUT) based on Scene-Luminance curves to avoid the generation of flickering. Prior to the AE control, a LUT is constructed, which illustrates the characteristic of outputs for input patches corresponding to sensor gains. The AE control is first performed by estimating a current scene as a patch using the proposed LUT. A new sensor gain is then estimated using also LUT with previously estimated patch. The entire estimation process is performed using linear interpolation to achieve real-time execution. Based on experimental results, the proposed AE control is demonstrated with real-time, flicker-free.

• Journal of Korea Multimedia Society
• /
• v.12 no.7
• /
• pp.903-912
• /
• 2009

There are still many difficulties in developing techniques for modifying or transforming the flickering of motion capture data or in modifying motion capture data in such a way that suits the animation timing sheet. There is a problem in the existing method of modifying motion capture data. It requires almost same time as in the key frame animation work by a very skilled animator or even more time in modifying. It is believed that this kind of problem can be a basis for a more effective problem-solving method through creating the key animation data node and direct blend layer and replacement layer nodes. This study presents a new method which enables to modify animation data in a nonlinear way without modifying the existing animation data by creating an animation layer node for a direct connection to the animation node. 'Maya' API will be utilized in order to realize this method and the research range will be limited to 'Maya' 3D software which is generally used in motion picture and animation films. According to the results of this study, the new method is much more intuitive than the nonlinear one and does not require the preceding working of making animation clips. In addition, it has enabled to modify flickering and to extract key frames, and due to the compatibility with other programs, it has been possible to modify motion capture data by creating a direct layer node. Finally, in this study, the existing method of modifying animation will be examined, compared and analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.8
• /
• pp.215-221
• /
• 2020

Navigation lights used in supersonic aircraft are used to identify the direction and location of the aircraft. The color of the navigation lights and location of installation are defined by aviation law as red for the left wing, green for the right wing, and white for the tail. Navigation lights operate in BRT and DIM modes. BRT is the brightest mode, and DIM is an output with dimmed brightness. Navigation lights serve to prevent aircraft collisions and are very important for stability and location identification. One phenomenon is that the inlet and tail navigation lights flicker abnormally. In this study, fault tree analysis was performed in two stages. The first step was derived from three causal factors, the second step developed five improvements, and the optimal improvement plan was drawn. The navigation lights confirmed that the initial input power was unstable as the main cause of abnormal flickering. As an improved method, the circuit was adjusted to stabilize the initial power, and it was confirmed that flickering did not occur as a result of the tests under the same conditions.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.12
• /
• pp.1193-1199
• /
• 2012

A cup burner experiment was performed to investigate the effect of the oxidizer velocity and concentration on flame instability near extinction. Heptane was used as a fuel and air diluted by nitrogen and carbon dioxide was used in the oxidizer stream. Two types of flame instabilities at the flame base and at axial downstream were observed near extinction. The instability at the flame base could be characterized by cell, swing, and rotation modes, and the cell mode changed to the rotation mode through the swing mode as the oxidizer velocity increased. To assess the parameters for the flame instability, the initial mixture strengths, Lewis number, and adiabatic flame temperature were investigated under each condition. The Lewis number might be the most important among them, but it is impossible to generalize because of the insufficient number of cases. Furthermore, the axial periodic flickering motion disappeared at low and high oxidizer velocities near extinction. This resulted from the fact that low oxidizer velocity induced evaporated fuel velocity below the critical velocity and high velocity made the reacting fuel velocity comparable.

• Journal of Sensor Science and Technology
• /
• v.27 no.3
• /
• pp.175-181
• /
• 2018

In this paper, we introduce a new dimming control method in a visible light communication (VLC) system wherein byteinversion is adopted for flicker-free transmission. In the VLC transmitter, the original and the inverted data were sent sequentially and the remnant time in one period was used for the dimming control of the LED light. In the VLC receiver, only the original data was recovered using the gating signal whose width was the same as the length of the original data. In our experiments, the dimming control ranges were measured to be 22%-53%, 11%-76%, and 5%-88% of the CW LED light when the data rates were 9.6, 19.2, and 38.4 kbps, respectively. In this system, we used a 240-Hz sync pulse whose period was 4.16 ms, which was shorter than the maximum flickering time period of 5 ms that is generally considered to be safe. This configuration is very simple and useful in constructing indoor wireless sensor networks using the flicker-free LED lamps with dimming control capability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.7
• /
• pp.1055-1061
• /
• 2002

This paper deals with a design and fabrication of an electronic ballast for 70[W] ceramic discharge metal halide lamps. The proposed ballast is composed of a rectifier, an active power factor correction circuit (PFC), a half-bridge inverter, a LC resonant circuit and a microprocessor. The developed ballast also includes a specially designed time circuit which provides reignition signal of lamps. Running frequency of the ballast is .jet at 40[kHz] to avoid acoustic-resonance and flickering. From the experimental results, input power factor and efficiency of the ballast are estimated 99.8[%] and 93.1[%], respectively.

• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.477-483
• /
• 2007

We have measured EOG and fMRI simultaneously to investigate whether eye movement (blinking mechanism) might influence functional magnetic resonance imaging (fMRI) signal response in the primary visual cortex. $T2^*-weighted$ Echo-Planar Imaging (EPI) with concurrent electrooculogram (EOG) was acquired in four subjects while they viewed a fixation point and a checkerboard with a flickering rate of 8Hz. With the help of EOG information we divided the experimental blocks into two different conditions: fixation and moving eye. We have compared the fMRI data of these two conditions. Our results have shown that there is no difference between these two conditions. This might suggest that eye blinking does not affect BOLD signal changes in the primary visual cortex. This means further that eye blinking can be ignored in data processing.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1035-1037
• /
• 2005

2.32-inch $320{\times}350$ TFT-LCD with high resolution (206PPI) for advanced mobile phones could be successfully developed. The compact pixel design based on PMOS SLS technique is used to achieve this high resolution. Gate driver and part of data driver are integrated onto the glass substrate. High brightness (170cd) and contrast ratio (400:1) were obtained with very low flickering and crosstalk levels.