Browsing by Author "Lin, Chun-Fu"

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Accuracy enhanced thermal face recognition
(2013-11-01)
Lin, Chun-Fu
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Lin, Sheng-Fuu
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電控工程研究所
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Institute of Electrical and Control Engineering
Human face recognition has been generally researched for the last three decades. Face recognition with thermal image has begun to attract significant attention gradually since illumination of environment would not affect the recognition performance. However, the recognition performance of traditional thermal face recognizer is still insufficient in practical application. This study presents a novel thermal face recognizer employing not only thermal features but also critical facial geometric features which would not be influenced by hair style to improve the recognition performance. A three-layer back-propagation feed-forward neural network is applied as the classifier. Traditional thermal face recognizers only use the indirect information of the topography of blood vessels like thermogram as features. To overcome this limitation, the proposed thermal face recognizer can use not only the indirect information but also the direct information of the topography of blood vessels which is unique for every human. Moreover, the recognition performance of the proposed thermal features would not decrease even if the hair of frontal bone varies, the eye blinks or the nose breathes. Experimental results show that the proposed features are significantly more effective than traditional thermal features and the recognition performance of thermal face recognizer is improved. (C) 2013 Elsevier B.V. All rights reserved.
Comparison of Geometric, Electronic, and Vibrational Properties for All Pentagon/Hexagon-Bearing Isomers of Fullerenes C(38), C(40), and C(42)
(2009-08-05)
Malolepsza, Edyta
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Lee, Yuan-Pern
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Witek, Henryk A.
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Irle, Stephan
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Lin, Chun-Fu
The self-consistent-charge density-functional tight-binding (SCC-DFTB) method is employed for computing geometric, electronic, and vibrational properties for various topological isomers of small fullerenes. We consider all pentagon/hexagon-bearing isomers of C(38), C(40), and C(42) as the second part of a larger effort to catalogue the CC distance distributions, valence CCC angle distributions, electronic densities of states (DOSs), vibrational densities of states (VDOSs), and infrared (IR) and Raman spectra for fullerenes C(20)-C(180) [analogous data for C(20)-C(36) were published previously in Malolepsza et al., J Phys Chem A, 2007, 111, 6649]. Common features among the fullerenes are identified and properties characteristic for each specific fullerene cage size are discussed. (c) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 1999-2011, 2009
Comparison of Geometric, Electronic, and Vibrational Properties for All Pentagon/Hexagon-Bearing Isomers of Fullerenes C-38, C-40, and C-42
(2009-08-05)
Malolepsza, Edyta
;
Lee, Yuan-Pern
;
Witek, Henryk A.
;
Irle, Stephan
;
Lin, Chun-Fu
The self-consistent-charge density-functional tight-binding (SCC-DFTB) method is employed for computing geometric, electronic, and vibrational properties for various topological isomers of small fullerenes. We consider all pentagon/hexagon-bearing isomers of C-38, C-40, and C-42 as the second part of a larger effort to catalogue the CC distance distributions, valence CCC angle distributions, electronic densities of states (DOSs), vibrational densities of states (VDOSs), and infrared (IR) and Raman spectra for fullerenes C-20-C-180 [analogous data for C-20-C-36 were published previously in Malolepsza et al., J Phys Chem A, 2007, 111, 6649]. Common features among the fullerenes are identified and properties characteristic for each specific fullerene cage size are discussed. (c) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 1999-2011, 2009
DESIGN OF AN AUTOMATED FEEDBACK CONTROL COOLING SYSTEM FOR SWIR LINEAR IMAGE SENSOR APPLICATION
(2010)
Chen, Chien-Hung
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Chen, Chih-Wen
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Lin, Chun-Fu
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Liao, Tai-Shan
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Hwang, Chi-Hung
Our novel automated feedback temperature controlled cooling system consists of a temperature measurement circuit, a TE cooler, a thermistor, a microcontroller, and a digital-to-analog converter and PWM algorithms. The measurement accuracy of this temperature controlled TE system was better than 0.1 degrees C and can be used for maintaining an instrument's isothermal applications. The experimental results of SWIR linear image shows that the temperature can be stably maintained at -20 degrees C, the dark output current can be reduced almost 80mV (Integration time: 100 ms) and the SNR of pixel can be improved from 48dB to 83dB as well.
Efficient face detection method with eye region judgment
(2013)
Lin, Chun-Fu
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Lin, Sheng-Fuu
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電控工程研究所
;
Institute of Electrical and Control Engineering
Real-time face detection technology can be applied in many industrial or commercial products. Many face detection applications use the traditional Adaboost face detection system which is proposed by Viola and Jones in 2004. Viola and Jones used the Adaboost training algorithm and the Haar-like features in their proposed traditional Adaboost face detection system, which has a high detection rate but long training time. Many studies have attempted to reduce the training time and retain the high detection rate of the traditional Adaboost face detection system. However, the detection rate of the Adaboost-based face detection system cannot compete with the traditional Adaboost face detection system when the training time is reduced significantly. This study proposes the judging existence of eye region (JEER) method to enhance the detection rate of the previous Adaboost-based face detection systems. The eyes are more salient and representative features than the other facial parts such as the mouth or ears, especially when mask is worn on the human face. Therefore, the proposed face detection system with the JEER method achieves higher detection rate than the Adaboost-based face detection systems. Although the JEER computation results in a slightly longer training time, the training time of the proposed face detection system is still much shorter than the traditional Adaboost face detection system owing to the efficient JEER computation. The experimental results obtained using the gray FERET and CMU databases show that the proposed face detection system is effective in detection and efficient in training.
Ictal networks of temporal lobe epilepsy: views from high-frequency oscillations in stereoelectroencephalography
(2019-10-01)
Peng, Syu-Jyun
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Chou, Chien-Chen
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Yu, Hsiang-Yu
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Chen, Chien
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Yen, Der-Jen
OBJECTIVE In this study, the authors investigated high-frequency oscillation (HFO) networks during seizures in order to determine how HFOs spread from the focal cerebral cortex and become synchronized across various areas of the brain. METHODS All data were obtained from stereoelectroencephalography (SEEG) signals in patients with drug-resistant temporal lobe epilepsy (TLE). The authors calculated intercontact cross-coefficients between all pairs of contacts to construct HFO networks in 20 seizures that occurred in 5 patients. They then calculated HFO network topology metrics (i.e., network density and component size) after normalizing seizure duration data by dividing each seizure into 10 intervals of equal length (labeled I1-I10). RESULTS From the perspective of the dynamic topologies of cortical and subcortical HFO networks, the authors observed a significant increase in network density during intervals I5-I10. A significant increase was also observed in overall energy during intervals I3-I8. The results of subnetwork analysis revealed that the number of components continuously decreased following the onset of seizures, and those results were statistically significant during intervals I3-I10. Furthermore, the majority of nodes were connected to a single dominant component during the propagation of seizures, and the percentage of nodes within the largest component grew significantly until seizure termination. CONCLUSIONS The consistent topological changes that the authors observed suggest that TLE is affected by common epileptogenic patterns. Indeed, the findings help to elucidate the epileptogenic network that characterizes TLE, which may be of interest to researchers and physicians working to improve treatment modalities for epilepsy, including resection, cortical stimulation, and neuromodulation treatments that are responsive to network topologies.
Inverting level-shift circuit has negative potential
(2012-07-01)
Lin, Chun-Fu
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Lin, Shir-Kuan
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Huang, Hui-Shun
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Chang, Jyi-Jinn
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Liao, Tai-Shan
Real-time Image Data Acquisition and Inspection System for Integrated Circuit Wafer after Sawing Process
(2016)
Lin, Chun-Fu
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Fang, Hong-Ren
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Sze, Jyh-Rou
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Lin, Sheng-Fuu
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Hwang, Chi-Hung
The major defect in integrated circuit wafers after the sawing process is the unexpected cracking from the sawing lane that damages the die area. Traditional defect detection algorithms for integrated circuit wafers after the sawing process can be divided into two parts. The first part is locating the sawing lane area and the second is detecting defects in the sawing lane area. The traditional methods take too long to locate the sawing lane area. To overcome this, this paper proposes a novel method for locating the sawing lane area using low-resolution and gray-value input images. After the sawing lane area is extracted from the original image, defects can be detected by traditional defect detection methods in the sawing lane area or by the method proposed in this paper. Using the proposed defect detection method is faster and better for real-time operation than traditional methods since the proposed method is more concise. Finally, a pioneering image data acquisition and inspection system for integrated circuit wafers after the sawing process is proposed in this paper. Furthermore, the proposed system works in real time because its architecture operates quickly and its proposed algorithm is simple, using low-resolution, gray-value images. Therefore, the proposed system can operate in real time and maintain a high-level detection rate.
Real-Time Image-Based Defect Inspection System of Internal Thread for Nut
(2019-08-01)
Lin, Chun-Fu
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Lin, Sheng-Fuu
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Hwang, Chi-Hung
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Tu, Hao-Kai
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Chen, Chih-Yen
The most important components of the internal nut thread inspection process are measuring the pitch and pitch diameter value and comparing these with their respective specifications, as a test nut is considered to be abnormal when its pitch or pitch diameter does not meet specifications. This paper focuses on defects arising when the pitch diameter does not meet its specification. Because conventional contact strategies are not suited to the real-time inspection of internal thread defects, there have been a number of recent attempts to develop noncontact methods for real-time measurement. Some approaches have applied laser triangulation techniques in which reflected light is used to measure the z-axis depth on an object's surface. Although point lasers have been shown to be highly precise in measuring pitch diameter, the optical architecture involved in these approaches is complicated and, as the laser must be scanned in a pointwise manner to derive cross-sectional measurements, the measurement process is too long to be compatible with real-time defect inspection. In this papere, an image-based method employing a line laser projector was used to develop a real-time image-based nut pitch diameter defect inspection system. The proposed method, which improves upon the conventional, widely used template-matching method for rapid defect detection, was shown to be effective through experimental validation.
Real-time Middle Wave Infrared Aerial Image Capturing and Stitching System for Vegetation Observation
(2015)
Lin, Chun-Fu
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Lin, Sheng-Fuu
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Hwang, Wen-Jyi
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Chen, Yung-Hsiang
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Hwang, Chi-Hung
Over the last decades, several studies have demonstrated the reflectance effectiveness of middle wave infrared (MWIR) for discriminating among different types of vegetation, and estimating the total and leaf biomass of several forest ecosystems. Therefore, a MWIR aerial image capturing system for vegetation observation is urgently required. Furthermore, stitching those MWIR aerial images together is necessary for a panorama of the region of interest (ROI). Most traditional stitching algorithms for aerial images are designed for visible images, and are not suitable for infrared images that are noisy, blurry, or lack detail. In this paper, a novel real-time MWIR aerial image capturing and stitching system for vegetation observation is proposed. The proposed stitching algorithm for aerial infrared images improved from scale invariant feature transform (SIFT) and random M-least square can find a sufficient number of feature points easily and perform rapid calculations. Therefore, the proposed MWIR aerial image capturing and stitching system for vegetation observation can operate in real time.
Real-time pedestrian detection system with novel thermal features at night
(2014-01-01)
Lin, Chun-Fu
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Lin, Sheng-Fuu
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Hwang, Chi-Hung
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Chen, Yu-Chieh
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電控工程研究所
Since the need of pedestrian detection at night has gained more and more interest, real-time pedestrian detection system at night has begun to attract significant attention. However, the detection performance of traditional pedestrian detection system at night is still insufficient since region of interests(ROI) generation and feature extraction are designed separately and less relative. This study presents a novel pedestrian detection algorithm and the corresponding system architecture for the real-time pedestrian detection system at night. The presented pedestrian detection algorithm uses novel outline features which have strong representative for the forward direction of pedestrian. A ROI generation method which is closely related to the outline features is presented to improve the detection accuracy. A three-layer back-propagation feed-forward neural network is applied as the classifier. Since the system architecture is efficiently and the calculation of the outline feature values is simple, the presented pedestrian detection system can operate in real-time. Experimental results show that the presented outline features are significantly effective and the detection performance of pedestrian detection system at night is improved.
Real-time Pitch Diameter Measurement of Internal Thread for Nut using Laser Triangulation
(2017-01-01)
Lin, Chun-Fu
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Hwang, Chi-Hung
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Fang, Hong-Ren
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Chen, Chih-Yen
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Sze, Jyh-Rou
In traditional industrial applications, the thread plug gauge is used to check the pitch diameter of the internal thread of a nut. However, the thread plug gauge can only be used to determine whether the nut was manufactured successfully rather than to measure the value of the pitch diameter. In recent years, several studies have employed a reflected light method such as laser triangulation to scan the outline of an object. However, most research studies using laser triangulation have developed measurement algorithms for specific objects because the properties of an object's appearance and the reflective laser from that object differ greatly. Existing algorithms are consequently not suitable for scanning the outline of the internal thread of a nut and measuring its pitch diameter with laser triangulation. In this paper, we propose a novel, real-time algorithm for measuring the pitch diameter of the internal thread of a nut using laser triangulation. First, a specific image preprocessing procedure designed for a reflective laser in the internal thread of a nut is presented. The result of preprocessing critically affects the measurement accuracy of the proposed method. Thereafter, we propose a measurement algorithm designed for the appearance properties of the internal thread of a nut. Our method can operate in real time because the proposed algorithm can measure the pitch diameter of the internal thread of a nut in only a few steps and simple calculations.