Browsing by Author "Chen, Yi-Fu"

Now showing 1 - 9 of 9

AMOLED panel driven by time-multiplexed clamped inverter circuit to reduce complex control signals
(2008-07-01)
Chen, Chun-Ho
;
Chen, Ke-Horng
;
Chen, Che-Chin
;
Chen, Yi-Fu
;
Shieh, Han-Ping D.
A time-multiplexing technique employing a pulse-width-modulation (PWM) charge-pump scheme for driving active-matrix organic light-emitting-diodes (AMOLEDs) is described. This scheme greatly reduces the number of control lines. The two-or four-phase PWM driving technique not only reduces costs through the simplification of manufacture but also improves the uniformity and lifetime of OLED panels. Experimental results show that the proposed circuit effectively and precisely controls the timing of OLED data-writing and light emission.
Free-electronlike diffusive thermopower of indium tin oxide thin films
(2010-12-15)
Wu, Chih-Yuan
;
Tra Vu Thanh
;
Chen, Yi-Fu
;
Lee, Jui-Kan
;
Lin, Juhn-Jong
We report our measurements of thermopower, S (T), on a series of indium tin oxide thin films from 300 down to 5 K to extract the carrier concentration n. The temperature behavior of S (T) below 300 K can be essentially described by a prevailing linear diffusive contribution. In this wide temperature interval, the phonon-drag thermopower is negligible relative to the diffusive thermopower. Therefore, the free-electronlike characteristic is clearly addressed. It should be stressed that linearity in S(d) from liquid-helium temperatures all the way up to room temperatures is seldom seen even in simple metals. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3524522]
Mask-RCNN Based People Detection Using A Top-View Fisheye Camera
(2019-01-01)
Wang, Tsaipei
;
Hsieh, Yun-Yi
;
Wong, Fong-Wen
;
Chen, Yi-Fu
;
資訊工程學系
People detection is a core problem in many applications, such as those related to visual surveillance and behavior analysis. In recent years, we have seen dramatic improvements of people detection techniques based on deep neural networks. However, most of the techniques are developed for projective cameras where people mostly appear upright in the images. On the other hand, images taken with top-view fisheye cameras, another major modality used in visual surveillance, have received little attention. In this paper, we present a study on extending the well-known Mask-RCNN people detection algorithm to such images.
Mixed color sequential technique for high contrast LCD with optimum power consumption
(2007)
Chen, Yi-Fu
;
Chen, Che-Chin
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a mixed color sequential (MCS) algorithm with high contrast enhancement technique in RGB LED backlight display. Owing to synchronous control of LCD and LED panels, high quality image with Suppressed color breakup and motion blur effects is achieved by our novel color sequential technique. Furthermore., high contrast image is also presented in LCD panel because of mixed RGB and CMY backlights with optimum power consumption. In other words, MCS algorithm with high contrast enhancement technique can have the better performance compared with other field sequential color techniques.
Mixed color sequential technique for reducing color breakup and motion blur effects
(2007-12-01)
Chen, Yi-Fu
;
Chen, Che-Chin
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a mixed color sequential (MCS) algorithm with high contrast enhancement technique in RGB light-emitting diode (LED) backlight display. Owing to synchronous control of liquid crystal display (LCD) and LED panels, high quality image with suppressed color breakup (CBU) and motion blur effects is achieved by our novel color sequential technique. Importantly, MCS algorithm is useful for color filter-less optical compensated bend (OCB) panel display for alleviating CBU and motion blur effects. Furthermore, high contrast image is also presented on LCD panel because of mixed red-green-blue (RGB) and cyan-magenta-yellow (CMY) backlights with optimum power consumption. In other words, MCS algorithm with high contrast enhancement technique can have the better performance compared with other field sequential color techniques. Experimental results demonstrate by an actual RGB backlight module for 32-in 1366*768 LCD panel the improvement of CBU and motion blur effects.
ON THE EFFECT OF DATA IMBALANCE FOR MULTI-LABEL PEDESTRIAN ATTRIBUTE RECOGNITION
(2018-01-01)
Wang, Tsaipei
;
Shu, Kai-Chen
;
Chang, Chia-Hao
;
Chen, Yi-Fu
;
資訊工程學系
Pedestrian attribute recognition has many applications in surveillance and attribute based query, tracking, and person re-identification. The recent trend in deep-learning based pedestrian attribute recognition is to use a shared CNN backbone for feature extraction and multiple subsequent branches for the individual branches. While this allows the end-to-end learning to simultaneously recognize multiple attributes, the data imbalance problem of most attributes becomes a challenge that has not been studied sufficiently for this application. This paper presents studies on how the cost adjustment method affects several common evaluation metrics. We also propose a two-stage training procedure, where an additional fine-tuning stage on the classifier layers only with class-balanced data is shown to improve recognition performances.
Spatial-temporal division in field sequential color technique for color filterless LCD
(2007)
Chen, Che-Chin
;
Chen, Yi-Fu
;
Liu, Ti-Ti
;
Chen, Chun-Ho
;
Ho, Ming-Tsung
For color filterless display, a novel spatial and temporal division (STD) field sequence color (FSC) display technique divides each frame into many temporary sub-frames for improving color breakup (CBU) and motion blur effects. Fast refresh frequencies enhance the image quality. Spatial and temporal division achieves low cost and power consumption.
Temperature dependence of resistance and thermopower of thin indium tin oxide films
(2010-09-30)
Lin, Bo-Tsung
;
Chen, Yi-Fu
;
Lin, Juhn-Jong
;
Wu, Chih-Yuan
;
電子物理學系
We have measured the resistance and thermopower of a series of RF sputtered and annealed indium tin oxide (ITO) thin films from 300 K down to liquid-helium temperatures. Thermal annealing was performed to modulate the levels of disorder (i.e., resistivity) of the samples. The measured resistances are well described by the Bloch-Grilneisen law between 150 and 300 K, suggesting that our thin films are metallic. At lower temperatures, a resistance rise with decreasing temperature was observed, which can be quantitatively ascribed to the two-dimensional electron-electron interaction and weak-localization effects. The thermopowers in all samples are negative and reveal fairly linear temperature dependence over the whole measurement temperature range, strongly indicating free-electron like conduction characteristics in ITO thin films. As a result, the carrier concentration in each film can be reliably determined. This work demonstrates that ITO films as thin as 15 nm thick can already possess high metallic conductivity. (C) 2010 Elsevier B.V. All rights reserved.
Temperature dependence of resistance and thermopower of thin indium tin oxide films
(2010-09-30)
Lin, Bo-Tsung
;
Chen, Yi-Fu
;
Lin, Juhn-Jong
;
Wu, Chih-Yuan
;
電子物理學系
We have measured the resistance and thermopower of a series of RF sputtered and annealed indium tin oxide (ITO) thin films from 300 K down to liquid-helium temperatures. Thermal annealing was performed to modulate the levels of disorder (i.e., resistivity) of the samples. The measured resistances are well described by the Bloch-Grilneisen law between 150 and 300 K, suggesting that our thin films are metallic. At lower temperatures, a resistance rise with decreasing temperature was observed, which can be quantitatively ascribed to the two-dimensional electron-electron interaction and weak-localization effects. The thermopowers in all samples are negative and reveal fairly linear temperature dependence over the whole measurement temperature range, strongly indicating free-electron like conduction characteristics in ITO thin films. As a result, the carrier concentration in each film can be reliably determined. This work demonstrates that ITO films as thin as 15 nm thick can already possess high metallic conductivity. (C) 2010 Elsevier B.V. All rights reserved.