• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.132-141
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• 1996

The pixelated phase grating has been studied as a kind of diffraction gratings splitting and input beam into multiple spots. It consists of regular size cells which produce phase delays, and each cell provokes the phase delay up to sixteen levels. We have compared and analyzed the characteristics of multi-level phase gratings, laying streess on efficiency and resulted pattern. Experimental resutls obtained form fabricated grating have been presented, and the real-time method using a liquid-crystal spatial light modulator has been demonstrated through experiments. Gratings making meams with specific intensities have been designed and optical images have been generated by them. In order to specific intensities have been designed and optical images have been genrated by them. In order to decide the phase delay of each cell, optimization conditon consists of diffraction efficiency and target values. One period of phase gratings fabricated with surface relief was less than 256${\mu}m{\times}256{\mu}m$ and size of each cell was 1${\mu}m{\times}1{\mu}m$ surface relief grating has been made by coating photoresist on the glass plate, writing information pattern by Ar laser and developing it. in the experiment for real-tiem processing liquid-crystal display of epson video projector has been used.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.3
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• pp.361-381
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• 2016

This study proposed two topical relevance models, simple and complex models, using EEG/ERP techniques. In the simple model regarding simple search tasks, N300 and P3b components are used. The N300 is specific to the semantic processing of pictures and the P3b reflects mechanisms involved in the decision about whether an external stimulus matches or does not match an internal representation of a specific category. In the complex model regarding complex search tasks, on the other hand, N400 and P600 components are used. The N400 reflects activation of an amodel system that integrates both image-based and conceptual representations into a context, whereas the P600 is related to complex cognitive processes. Our research results can be used as a source to design an EEG-based interactive multimedia system.

• Journal of ILASS-Korea
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• v.5 no.1
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• pp.5-12
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• 2000

The beneficial aspects of applying emulsion fuels to combustion systems may be due to the changes of fuel properties which lead to the enhanced atomization characteristics. The spray characteristics of water/oil emulsified fuel injected from the pressure-swirl(simplex) atomizer using for oil burner were investigated. Four different water contents from 10 to 40 % by volume at 10% increment were prepared by mixing with the different contents of surfactants. Total amount of surfactant used was varied from 1 to 3 % by volume. This study demonstrates the influence of water and surfactant contents of emulsified fuel, injection pressure on the spray characteristics, i.e. Sauter mean diameter(SMD) and spray angle. The drop size distribution of the emulsified fuel spray was measured with a Malvem particle sizer. In order to measure the spray angle, the digital image processing was employed by capturing multiple images of the spray with 3-CCD digital video camera. It was evident that the addition of water and surfactant changes fuel properties which are the key parameters influencing the atomization of the spray. The increase in surfactant content results in the decrease of SMD and the increase in spray angle. The droplets decease with increase in injection pressure, but the influence of injection pressure in this experimental condition was less important than expected. The more viscous fuel with the increase of water content exhibits the larger droplets in the centerline of the spray, and the less viscous fuel in the outer edges of the spray. The increase in axial position from the nozzle causes the spray angle to decrease. The spray angle decreases with increase in water content. This is due to increase in viscosity with increase in water content.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.9-14
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• 2015

Touch interface is widely used in a smartphone instead of a keyboard or a keypad interface that has been adopted in a PC or a featurephone, respectively. Touch interface can recognize a variety of gestures that clearly represent the distinct features of each application's input. This paper analyzes users' gesture of each application captured by the touch interface of a smartphone. Specifically, we extract touch input traces from various application categories such as game, web browser, youtube, image and e-book viewer, video player, camera, and map applications, and then analyzed them. Through this analysis, we observed a certain unique characteristics of each application's touch input, and this can be utilized in various useful areas such as identification of an application user, prevention of running an application by an illegal user, or design of a new interface convenient to a specific user.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.131-136
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• 2016

In this paper, we propose an Raspberry Pi2-based smart home security monitoring system. Proposed home security monitoring system was configured using a relatively tractable main processor raspberry pi2, ultrasonic sensors, and PIR sensors. In addition, The picamera is compatible with raspberry pi2 was connected to the servo motor. And by driving the attacker's location the video was recording. The Web server stores data of the recorded image and the sensor, and provides a web page to enable the monitoring at all remote locations. When examining efficiency of proposed home security monitoring system it was found that proposed system is easier to be made than existing home security system and is able to minimize the blind spot of the camera by using servo motor and is efficient and convenient and stable as it enables a user to handle an error in person and it uses reliable data.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.106-112
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• 1998

Recently, the amount of image and audio data has been increasing dramatically for high performance. According to this trend, a high-density magnetic recording system is necessitated and the tracks of magnetic tapes are getting narrower. This, in turn, requires the capstan servo system of the magnetic recording system such as DVCR to control precisely the speed and position of the capstan motor. Especially, in case of play-back, the capstan servo system should be able to position and maintain the head on the desired place of the track. To meet this requirement, digital camcorders use ATF (Automatic Track Following). In this paper, a new ATF block using discrete Fourier transform is proposed. The proposed ATF block was designed and implemented in ALTERA FPGA chips and fully tested in a real DVCR system. It is shown through experiments that the new ATF block is more cost-effective than other existing ATF blocks using digital lowpass filters. In particular, the number of logic gates can be reduced by 20% in average, compared to the existing ATF's.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.1-14
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• 2010

With the rapid growth of 3D content industry fields, 3D content-based hashing (or hash function) has been required to apply to authentication, trust and retrieval of 3D content. A content hash can be a random variable for compact representation of content. But 3D content-based hashing has been not researched yet, compared with 2D content-based hashing such as image and video. This paper develops a robust 3D content-based hashing based on key-dependent 3D surface feature. The proposed hashing uses the block surface coefficient using shape coordinate of 3D SSD and curvedness for 3D surface feature and generates a binary hash by a permutation key and a random key. Experimental results verified that the proposed hashing has the robustness against geometry and topology attacks and has the uniqueness of hash in each model and key.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.22-29
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• 2010

A real-time detection and tracking of moving objects in video sequences is very important for smart surveillance systems. In this paper, we propose a novel algorithm for the detection of moving objects that is the entropy-based adaptive Gaussian mixture model (AGMM). First, the increment of entropy generally means the increment of complexity, and objects in unstable conditions cause higher entropy variations. Hence, if we apply these properties to the motion segmentation, pixels with large changes in entropy in moments have a higher chance in belonging to moving objects. Therefore, we apply the Clausius entropy theory to convert the pixel value in an image domain into the amount of energy change in an entropy domain. Second, we use an adaptive background subtraction method to detect moving objects. This models entropy variations from backgrounds as a mixture of Gaussians. Experiment results demonstrate that our method can detect motion object effectively and reliably.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.482-485
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• 2006

Video-assisted thoracoscopic surgery has gained a broad acceptance for various thoracic lesions because it is the minimally invasive surgery with little tissue trauma, less pain, improved cosmetic results and short recovery time. However, there are some limitations for this method, such as restricted visual sensory information to a two-dimensional image and limited maneuverability of the tips of the instruments. To overcome these limitations, advanced technology has been introduced and the da $Vinci^{TM}$ Surgical System (Intuitive Surgical Inc, Mountain View, CA, USA) became available in 2001. In Korea, the da $Vinci^{TM}$ Surgical System was introduced in Severance hospital (Yonsei University College of Medicine) in May 2005, and approved by KFDA in July 2005. Herein, we report the first experience of robot-assisted thoracic surgery with the da $Vinci^{TM}$ Surgical System in extirpation of a large teratoma in anterior mediastinum.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.4
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• pp.62-70
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• 2012

In this paper, we propose the gunnery detection method based on reference frame modeling and frame difference method. The frame difference method is basic method in target detection, and it's applicable to the detection of moving targets. The goal of proposed method is the detection of gunnery target which has huge variation of energy and size in the time domain. So, proposed method is based on frame difference, and it guarantee real-time processing and high detection performance. In the method of frame difference, it's important to generate reference frame. In the proposed method, reference frame is modeled and updated in real time processing using statistical values for each pixels. We performed the simulation on 73 IR video data that has gunnery targets, and the experimental results showed that the proposed method has 95.7% detection ratio under condition that false alarm is 1 per hour.