• Journal of Information Display
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• v.6 no.4
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• pp.35-39
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• 2005

In this paper, we investigate the oxide cathodes for the development of reliable electron sources. Poisoning in oxide cathodes is one of the serious problems in achieving reliable electron emission. In particular, early poisoning induces poor life performance as will be demonstrated herein. The survivability of electron emission sources is significantly improved by high doping of high-speed activator. The robust oxide cathodes with 0.17 % Mg operating at about 1,050 K are expected to work for very long times (>100,000 hours). We suggest that this key idea will contribute to solving the basic problems in oxide cathodes such as poisoning or ion bombardment for high power or high frequency applications of electron sources.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.63-68
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• 2004

Since rotor position information is necessary to drive the SRM, absolute-encoder, resolver and incremental-encoder is used to detect a poor position. But, it is not desirable to use a high priced encoder and high efficient microprocessor under the condition of the simple driving system when precision control is not demanded. In this paper, Only using the reflective type 2 photosensors replace the conventional opto interrupter and slotted disk, which not only remove a slotted disk section but drive 3-phase 6/4 SRM bidirectionally. Moreover, as control circuit only is composed of common analog device economy is maximized.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.238-244
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• 2021

Image mosaicking is a common and useful technique to visualize a global map by stitching a large number of local images obtained from visual surveys in underwater environments. In particular, visual inspection of underwater structures using underwater robots can be a potential application for image mosaicking. Feature-based pairwise image registration is a commonly employed process in most image mosaicking algorithms to estimate visual odometry information between compared images. However, visual features are not always uniformly distributed on the surface of underwater structures, and thus the performance of image registration can vary significantly, which results in unnecessary computations in image matching for poor-conditioned image pairs. This study proposes a pairwise registrability measure to select informative image pairs and to improve the overall computational efficiency of underwater image mosaicking algorithms. The validity and effectiveness of the image mosaicking algorithm considering the pairwise registrability are demonstrated using an experimental dataset obtained with a full-scale ship in a real sea environment.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.607-610
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• 2002

Even though digital video coding techniques have been developed very rapidly, rate controlling is still an unsolved problem. This paper presents a new scene adaptive video encoding scheme for MPEG-1 and MPEG-2 video encoders. Degradation of picture quality at scene changes due to poor prediction of global complexity measure is addressed. The proposed scheme determines the picture types adaptively based on scene contents of each video frame. The effective placement of reference and inter-reference frames is studied at sudden scene changes and gradual scene changes respectively. Results show that the proposed scheme demonstrates a significant improvement in performance compared to TM5〔1〕.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.6
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• pp.319-327
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• 2013

Most Android applications are being developed by one or a few person without professional testing team. In such a poor development environment, applications may contain severe errors which may also affect the Android platform. In order to detect these errors, the behaviors of Android activities should be identified by considering user-defined lifecycle as well as the system-defined one. This paper proposes a method to generate test scenarios based on the both of user-defined and system-defined activity lifecycle of Android GUI applications. The test scenarios are generated by a state diagram extracted from the source code and are transformed into Jython scribes by using GUI layout information for automatically performing testing.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.628-631
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• 2003

In this paper, we present real-time, accurate face region detection and tracking technique for an intelligent surveillance system. It is very important to obtain the high-resolution images, which enables accurate identification of an object-of-interest. Conventional surveillance or security systems, however, usually provide poor image quality because they use one or more fixed cameras and keep recording scenes without any cine. We implemented a real-time surveillance system that tracks a moving person using four pan-tilt-zoom (PTZ) cameras. While tracking, the region-of-interest (ROI) can be obtained by using a low-pass filter and background subtraction. Color information in the ROI is updated to extract features for optimal tracking and zooming. The experiment with real human faces showed highly acceptable results in the sense of both accuracy and computational efficiency.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.185-188
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• 2001

In this study, $Al_2$O$_3$films have been deposited with Atomic Layer Deposition(ALD) for gate insulator for MPTMA and $H_2O$ at low temperature below 40$0^{\circ}C$ . Conventional methods of $Al_2$O$_3$thin film deposition have suffered from the poor step coverage due to reduction of device dimension and increasing contact/via hole aspect ratio. ALD is a self-limiting growth process with controlled surface reaction where the growth rate is only dependent on the number of growth cycle and the lattice parameter of materials. ALD growth process has many advantages including accurate thickness control, large area and large batch capability, good uniformity, and pinholes freeness.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.4
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• pp.30-44
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• 2003

In the microcell-or picocell-based system the frequent movements of mobiles bring about excessive traffics into the networks. A mobile location estimation mechanism can facilitate both efficient resource allocation and better QoS provisioning through handoff optimization. Existing location estimation schemes consider only LOS model and have poor performance in presence of multi-path and shadowing. In this paper we study novel schemes which can increase estimation accuracy by considering NLOS environment and other multiple decision parameters than the received signal strength.

• Journal of KIBIM
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• v.12 no.4
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• pp.32-40
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• 2022

The block-unit housing renewal project was presented as an alternative method to overcome the side effects of large-scale renewal projects while improving poor residential conditions. However, projects implementation is prolonged and even the pace of projects, which was considered an various incentives, is being delayed for the most part. In this study, delay factors are drawn by eight; conflict among association members, contract delay of joint implementation, participation paucity of constructor, inadequate project guidelines, alteration of project plan, lack of renewal project professionals, stricter loan restriction of HUG, lack of capacity of project operator. We categorized those eight factors to three aspects such as implementation, participants and proposition and suggested improvement alternatives according to three aspects.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.107-112
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• 2017

In this paper, I studied several universities which are especially famous for video and media fields in the United States to develop our international competitiveness. I selected the outstanding US universities and researched the various indexes of corresponding department, internship program and other activities related with company. Then, analyzed the research results and compared with the department of Video Broadcasting at the K women's university in our country. As a result, the retention rate and the graduate rate of the 4-years universities(bachelor's degree) are very higher than the 2-years associated degree among the US universities. On the other hand, although the department of Video Broadcasting at the K women's university is the associated degree course, it shows up the highest the retention rate and the graduate rate than the US universities. Therefore, we are able to recognize that K Women's University has managed its students well. However, the employment rate of the K Women's University was poor than the US universities due to the lack of the internship programs, other activities supported by companies and the career service center.