• 한국연소학회:학술대회논문집
• /
• 2006.04a
• /
• pp.26-31
• /
• 2006

Flickering behaviors of lean premixed flame of propane/air and methane/air flame anchored by a pilot flame in a tube were investigated. Unsteady behaviors of the flame were monitored by a high speed ICCD camera and the flickering frequency was defined as the number of flame curvatures passing a fixed spatial point in a second. Unlike previous studies in which flames are in open condition so that the flickering mechanism is an unstable interaction of hot buoyant products with the ambient air, flames in this study are surrounded by a tube which means they are not open to ambient air, so that there is no interaction between hot buoyant products and ambient air. Despite the fact, there exists flickering phenomena and the flickering frequency ranges from 10 Hz to 50 Hz which is wider compared to previous studies. We relate the flickering mechanism to flame-generated vorticity and analytic solution for locally approximated flow is used. As a result, the relationship between flickering wavelength and dimensionless vorticity is acquired and the cause of higher range of flickering frequency is explained.

• IEIE Transactions on Smart Processing and Computing
• /
• v.3 no.6
• /
• pp.358-365
• /
• 2014

This paper proposes a method that reduces the flickering effect caused by A-GLG (Adaptive Gray-Level Grouping) during video contrast enhancement. Of the GLG series, A-GLG shows the best contrast enhancement performance. The GLG series is based on histogram grouping. Histogram grouping is calculated differently between the continuous frames with a similar histogram and causes a subtle change in the transformation function. This is the reason for flickering effect when the video contrast is enhanced by A-GLG. To reduce the flickering effect caused by A-GLG, the proposed method calculates a modified transformation function. The modified transformation function is calculated using a previous and current transformation function applied with a weight separately. The proposed method was compared with A-GLG for flickering effect reduction and video contrast enhancement. Through the experimental results, the proposed method showed not only a reduced flickering effect, but also video contrast enhancement.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.617-622
• /
• 2003

Light Flickering of the lamp(fluorescent lamp) with voltage fluctuation operates as an factor harmful to train passengers which is subjective to them. Recently, international flickering standard(IEC61000-3-3) are applied all over the world. However, there are not any study preparing for regulation about light flickering inside running train. In this study, the Flicker phenomenon is investigated from several references and also how the flickermeter is configured and defined. Flicker evaluation using it are studied.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.8
• /
• pp.51-57
• /
• 2014

In this paper, we propose a novel method to effectively eliminate flickering artifacts caused by dehazing in video sequences. When applying a dehazing technique directly to each image in a video sequence, flicker artifacts may occur because atmospheric values are calculated without considering the relation of adjacent frames. Although some existing methods reduce flickering artifacts by calculating highly correlated transmission values between adjacent frames, flickering artifacts may still occur. Therefore, in order to effectively reduce flickering artifacts, we propose a novel approach considering temporal averages of atmospheric light values calculated from adjacent frames. Experimental results have shown that the proposed method achieves better performance of video dehazing with less flickering artifact than existing methods.

• The Journal of the Korea Contents Association
• /
• v.6 no.8
• /
• pp.57-67
• /
• 2006

The motion effect of animation can be maximized by using the intended number of frame(flickering phenomena) responding to the viewer's perception in the production processes. But, the high contrast of chroma in a color arrangement can cause very dangerous situation if a particular effect(scheduled number of frame for the intended rapid flickering in a zoom-in scene of the warning light of police car and the traffic light) or a excessive visual stimulus is tried. The danger of flickering phenomena is defined as 'Flash Nervousness Attack Symptom' in medical terminology, which has received wide attention because the damage to the viewers of Pocket Monster was very serious in Japan. Producing a piece of animation work, the quality control of colors is important but the color setting considering the psychological aspects, the danger of repetitive flickering of flashes and patterns in image effect are more serious, so these factors should be checked in the production stages. After investigating the domestic and foreign prescriptions including the guidelines for animation production technique in Japan, a solution to reduce the danger of flickering phenomena of color and light was suggested through statistical comparative analysis with the test results.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.301-304
• /
• 2002

컴퓨터에 있어서 멀티미디어는 발전가능성이 풍부한 분야이다. 이러한 멀티미디어는 하드웨어 및 소프트웨어, 네트워크 환경의 발달로 인하여 더욱 더 크고 많은 데이터가 전송될 것이다. 이에 더 좋은 데이터를 더 빠르고 손실 없이 전달하는 것은 중요한 문제이다. 이에 멀티미디어 데이터의 전송 및 재생에 있어서 하나의 문제로 떠오를 수 있는 깜빡임 현상(Flickering)에 대해서 연구하고자 한다.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
• /
• 2002.05a
• /
• pp.273-278
• /
• 2002

Modern society is an interaction between many different environments. It is important to the mutual relationships between people and especially between people and the environment. One of the mutual relationships between people and the environment is the traffic system, especially the traffic signals which give priority to pedestrian and traffic flow. Traffic signals for the pedestrian on the crosswalk contribute to a safe road environment for the pedestrian, while the traffic signals for the pedestrian running for the flickering of the green signal causes psychological stress. Therefore, this study investigated whether the walking velocity was influenced by the flickering of the green signal or not. Also, this study investigated whether the walking distance had an effect on the walking velocity of the elderly pedestrian or not. It was proved that the flickering of the green signal and the walking distance influenced the walking velocity and subjective sensitiveness according to the result of this study.

• Journal of Aerospace System Engineering
• /
• v.15 no.2
• /
• pp.45-51
• /
• 2021

In this study, we aim to eliminate the flickering phenomenon in multi-function display (MFD) units during the flight of fixed-wing aircraft. To execute flight missions effectively, the video signals transmitted to MFDs must provide information accurately and seamlessly. Therefore, a method for addressing the flickering phenomenon-including cause analysis and failure diagnosis-is adopted; specifically, a wiring configuration with a direct connection between the video signal cables and with a short cable length is adopted. The proposed method is experimentally verified using a flight test.

• Journal of Satellite, Information and Communications
• /
• v.8 no.4
• /
• pp.89-94
• /
• 2013

This paper presents color video flame detection algorithm based on wavelet transform to remove detection of flickering non-flame objects. Conventional flame detection algorithms consist of simple or mixed functions using colors, temporal and spatial characteristics. But those algorithms detect non-flame objects as flame regions sometimes. False alarm reasons are flame-like objects with regular flickering lights such as car signal lamps, alarm lights etc. The proposed algorithm is to reduce false detection which is occurred in periodic flickering lights. At first, It segments the candidate flame regions by using frame difference, flame colors. Then it distinguish flame regions and non flame regions including flickering car lights by analyzing wavelet coefficients. Computer simulation results showed that the proposed algorithm removes false detection due to the periodic flickering lamps by performing 97.9% of correct detection rate while false detection rate is 7.3%.

• Journal of Broadcast Engineering
• /
• v.15 no.3
• /
• pp.321-331
• /
• 2010

Most of multimedia video coding algorithms are lossy schemes and several kinds of spatial and temporal artifacts are inevitable. Flickering, which is the most typical coding artifact in time domain, is mainly due to fact that the quality of coded sequence fluctuates as the quantization parameter is adjusted for rate control. In this paper, we analyzed the effect of quality variation according to the characteristics of video sequence when the I-frames are periodically inserted. And we proposed the FR(Full Reference)-based assessment algorithm to measure the amount of flickering artifacts in the coded video. It is discovered that the flickering becomes critical when the level of quality is intermediate and is affected by the amount of detail or movement, the size of object, and camera parameters. The proposed measurement algorithm shows is well consistent with HVS(Human Visual System).