• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1287-1292
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• 2005

This paper presents an effective pattern classification model by designing an artificial neural network based pattern classifiers for face recognition. First, a RGB image inputted from a frame grabber is converted into a HSV image which is similar to the human beings' vision system. Then, the coarse facial region is extracted using the hue(H) and saturation(S) components except intensity(V) component which is sensitive to the environmental illumination. Next, the fine facial region extraction process is performed by matching with the edge and gray based templates. To make a light-invariant and qualified facial image, histogram equalization and intensity compensation processing using illumination plane are performed. The finally extracted and enhanced facial images are used for training the pattern classification models. The proposed H-ART2 model which has the hierarchical ART2 layers and F-LVQ model which is optimized by fuzzy membership make it possible to classify facial patterns by optimizing relations of clusters and searching clustered reference patterns effectively. Experimental results show that the proposed face recognition system is as good as the SVM model which is famous for face recognition field in recognition rate and even better in classification speed. Moreover high recognition rate could be acquired by combining the proposed neural classification models.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.960-967
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• 2013

Shape recognition of solder ball bumps in a BGA (Ball Grid Array) is an important issue in flip chip bonding technology. In particular, the semiconductor industry has required faster and more accurate inspection of micron-size solder bumps in flip chip bonding as the density of balls has increased dramatically. The difficulty of this issue comes from specular reflection on the metal ball. Shape recognition of a metal ball is a very realproblem for computer vision systems. Specular reflection of the metal ball appears, disappears, or changes its image abruptly due to tiny movementson behalf of the viewer. This paper presents a practical shape recognition method for three dimensional (3-D) inspection of a BGA using a 5-step ring illumination device. When the ring light illuminates the balls, distinctive specularity images of the balls, which are referred to as "iso-slope contours" in this paper, are shown. By using a mathematical reflectance model, we can drive the 3-D shape information of the ball in aquantitative manner. The experimental results show the usefulness of the method for industrial application in terms of time and accuracy.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.43-48
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• 2006

Recently, many researchers have shown great interest in wind-photovoltaic hybrid generation system which promotes electric power supply safely and progress of energy usage efficiently with complementary cooperation of a wind generation system and photovoltaic generation system. To use this hybrid generation system stably and effectively, we established a system which can acquire, analyse and save data and monitored remotely using internet. We constructed the signal conditioning circuit and used many kinds of converters to measure physical quantities such as wind velocity, intensity of illumination and temperature as well as many kinds of voltage and current for AC and DC. we acquired data from computer with data acquisition board, developed server program and client program which can download data that is monitored and saved in realtime at remote place. We analysed the measured data in relation to many conditions such as time and weather conditions.

• Journal of the Korean Solar Energy Society
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• v.35 no.6
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• pp.1-7
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• 2015

This paper deals with the design and operation of a hybrid daylighting system that uses natural and artificial lighting to enhance visual comfort in buildings. The system was developed using an AVR micro controller for solar tracking in conjunction with dimming controls, which, acting together, enables the maximum use of natural daylight and also improves energy efficiency in buildings. Experimental results clearly demonstrates the usefulness of the present system capable of enhancing indoor lighting conditions when sufficient daylight is available and distributed appropriately in harmony with artificial lighting.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.196-203
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• 2008

Hybrid robust image processing algorithm to extract visual features of melon during the cultivation was developed based on a wireless tele-operative interface. Features of a melon such as size and shape including position were crucial to successful task automation and future development of cultivation data base. An algorithm was developed based on the concept of hybrid decision-making which shares a task between the computer and the operator utilizing man-computer interactive interface. A hybrid decision-making system was composed of three modules such as wireless image transmission, task specification and identification, and man-computer interface modules. Computing burden and the instability of the image processing results caused by the variation of illumination and the complexity of the environment caused by the irregular stem and shapes of leaves and shades were overcome using the proposed algorithm. With utilizing operator's teaching via LCD touch screen of the display monitor, the complexity and instability of the melon identification process has been avoided. Hough transform was modified for the image obtained from the locally specified window to extract the geometric shape and position of the melon. It took less than 200 milliseconds processing time.

• Journal of the Optical Society of Korea
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• v.20 no.4
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• pp.488-499
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• 2016

We present a design and optical simulation of a cost-effective hybrid daylighting/LED system composed of mixing sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting. In this approach, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The proposed sunlight collector consists of a Fresnel lens array. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. The visible rays passing through the beam splitters are coupled to a stepped thickness waveguide (STW) by tilted mirrors and confined by total internal reflection (TIR). LEDs are integrated at the end of the STW to improve the lighting quality. LEDs’ light and sunlight are mixed in the waveguide and they are coupled into an optical fiber bundle for indoor illumination. An optical sensor and lighting control system are used to control the LED light flow to ensure that the total output flux for indoor lighting is a fixed value when the sunlight is inadequate. The daylighting capacity was modeled and simulated with a commercial ray tracing software (Lighttools^TM). Results show that the system can achieve 63.8% optical efficiency at geometrical concentration ratio of 630. A required accuracy of sun tracking system achieved more than ±0.5^o . Therefore, our results provide an important breakthrough for the commercialization of large scale optical fiber daylighting systems that are faced with challenges related to high costs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5904-5927
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• 2019

Many artificial intelligence (AI) techniques have been embedded into various engineering technologies to assist them in achieving different goals. The integration of modern technologies with energy consumption management system and occupant's comfort inside buildings results in the introduction of intelligent building concept. The major aim of this integration is to manage the energy consumption effectively and keeping the occupant satisfied with the internal environment of the building. The last few couple of years have seen many applications of AI techniques for optimizing the energy consumption with maximizing the user comfort in smart buildings but still there is much room for improvement in this area. In this paper, a hybrid of two AI algorithms called firefly algorithm (FA) and genetic algorithm (GA) has been used for user comfort maximization with minimum energy consumption inside smart building. A complete user friendly system with data from various sensors, user, processes, power control system and different actuators is developed in this work for reducing power consumption and increase the user comfort. The inputs of optimization algorithms are illumination, temperature and air quality sensors' data and the user set parameters whereas the outputs of the optimization algorithms are optimized parameters. These optimized parameters are the inputs of different fuzzy controllers which change the status of different actuators according to user satisfaction.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2321-2324
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• 2013

An improved hybrid solar cell was obtained by focusing on the effects of ligand for CdSe nanoparticles, in the active layers. The performance was compared by mixing nanoparticles capped with pyridine or oleic acid for the acceptor material into poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester based active layer. The solar cells with pyridine capped CdSe nanoparticles showed a power conversion efficiency of 2.96% while oleic acid capped CdSe nanoparticles showed 2.85%, under AM 1.5G illumination. Formation of percolation pathways for carrier transport and a reduction in the hopping event resulted in better performance of pyridine capped nanoparticles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2622-2627
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• 2010

The accuracy of face recognition used unmanned security system is very important and necessary. However, face recognition is a lot of restriction due to the change of distortion of face image, illumination, face size, face expression, round image. We propose a hybrid neural network for improve the performance of the face recognition. The proposed method is consisted of SOM and LVQ. In order to verify usefulness of the proposed method, we make a comparison between eigenface method, hidden Markov model method, multi-layer neural network.

• KIEAE Journal
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• v.4 no.2
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• pp.11-18
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• 2004

Growing use of entire glass facades with metal frames are popularly witnessed in modern building practices and design competition as well. In spite of architectural aesthetics and view to outdoors, environmental issues still exist in that kind of buildings. One of the solutions for the problems might be the use of functional glasses such as a heat-resistant glass or various tinted glasses for the glass walls. This paper aims to provide performance data related to the impact of various transmittal materials of window systems on the light distribution. A series of computer simulation deals with the basic geometrical and optical design elements of a commonly used all-glass facades. Additionally an experimental configuration of the vertical window is proposed for better result of daylighting. A window system equipped with an inner-light shelf can improve the uniformity of natural light in a space by reducing the level of illumination near the window and redirecting light deeply into the space.