• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1051-1055
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• 2005

In this paper, the trend of the market demand for the technology of railway cars and the development direction of other country or company were studied by analysing the patent map. The effort for developing the technology is intensified from the middle of 1960s and it seems to be more strengthened especially in the parts of bogie, driving motor/power, window and door. Recently the increasing rate of the number of patent application from Germany and China is noticeable. The results of this paper can be used for making the development plans of competitive technologies and benchmarking of them.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.4
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• pp.229-235
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• 2014

This paper presents an environmental navigation system which provides a guidance to the users of smart bicycle for a pollution-free route during their travel. The smart bicycle operates as a sensor node being composed of a distributed wireless sensor network over the whole urban area. Several environmental sensors measuring the amount of dust, CO, $CO_2$, $NO_2$ in the air are built into the smart bicycle to estimate the level of air pollution in the located area. Each smart bicycle sends/receives the measured sensor data and the city pollution map to/from the centralized server, which leads the bike-riders to a healthy route by providing the environmental navigation information. The proposed idea and its implementation give a useful insight on various application services with the distributed smart bicycles.

• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.40-45
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• 2005

Substation facilities have become extremely large and complex parts of electric power systems. The development of condition monitoring and diagnosis techniques has been a very significant factor in the improvement of substation transformer security. This paper presents a method to analyze the cause, the degree, and the aging process power transformers by the Self Organizing Map (SOM) method. Dissolved gas data were non-linearly transformed by the sigmoid function in SOM that works much the same way as the human decision making process. The potential for failure and the degree of aging of normal transformers are identified by using the proposed quantitative criterion. Furthermore, transformer aging is monitored by the proposed criterion for a set of transformers. To demonstrate the validity of the proposed method, a case study is performed and its results are presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.154-159
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• 1997

In this paper, we describe the OGY method that convert the motion on a chaotic attractor to attracting time periodic motion by malting only small perturbations of a control parameter. The OGY method is illustrated by application to the control of the chaotic motion in chaotic attractor to happen at the famous Logistic map and Henon map and confirm it by making periodic motion. We apply it the chaotic motion at the behavior of the thin beam under periodic torsional base-excitation, and this chaotic motion is made the periodic motion by numerical experiment in the time evaluation on this chaotic motion. We apply the OGY method with the Jacobian matrix to control the chaotic motion to the periodic motion.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.269-271
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• 2020

In this letter, we propose a novel approach for stitching stereoscopic panoramas. When stitching stereoscopic panoramas, the amount of depth retrieved is the most important factor to pay attention for. Also, it is very crucial to deliver the two left and right panoramas with the right depth information to deliver good 3D perception. However, when stitching the two panoramas independently using the state-of-the-art algorithms and methods, we do still have some inconsistencies with the disparity map retrieved from the panoramas. To overcome this problem, we propose a method that modifies the latest conventional algorithm by making the two panoramas dependent of one another. This brings two panoramas with a much more consistent disparity map that lets users fully immerse into a comfortable stereoscopic vision.

• Korean Journal of Plant Taxonomy
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• v.53 no.2
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• pp.110-125
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• 2023

On the Korean Peninsula, eleven species of the genus Liparis (Orchidaceae) have been recorded, and three species are presumed to belong to the L. makinoana complex. These are L. koreana, L. japonica, and L. makinoana. Liparis japonica and L. makinoana are distributed in South Korea, but the distribution of L. koreana has not been confirmed. Liparis japonica and L. makinoana are morphologically very similar, making it difficult to classify them. Recently, L. japonica and L. makinoana in Japan were reclassified into three species. One of them is an amended species of L. makinoana, and the other two species were described as new species, specifically L. longiracemosa and L. suzumushi. It was confirmed that the three species are distributed in South Korea. Here, we provide a distribution map, photographs of the three new species, and a comparison of their morphological characteristics.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.120-132
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• 2019

As a key infrastructure for positioning autonomous vehicles, HD maps are making efforts to equip autonomous vehicles and connect them with services worldwide. Global companies like Here and TomTom have contracted an agreement with three German automobile companies(BMW, Audi, Daimler) by establishing systems including from the production of HD maps to loading autonomous vehicles. Japan has organized a DMP(Dynamic Map Platform) by collaborating public and private section and performing establishment of HD map on private section-oriented. Korean companies related with autonomous vehicles are also cooperating with various companies such as vehicles, sensors and maps. But public and private sections are establishing HD maps respectively. Accordingly, Ministry of Land, Infrastructure and Transport implemented and signed memorandum for private and public cooperation in April 2019, Joint establishment council of HD map has launched in August 2019. This study performed domestic and foreign trend analysis about HD map and interviewed to related companies. And analyzed solutions for interactive cooperation of private and public section in HD map industry, purposed step-by-step strategy for operation and operation plan for joint establishment council of HD map.

• Journal of the Korean Professional Engineers Association
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• v.41 no.5
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• pp.55-58
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• 2008

GPS is the global Navigation Satellite System which is developed by the United States Department of Defense as an abbreviation of the Global Positioning System. The GPS uses a constellation of 24 Medium Earth Orbit satellites that transmit precise microwave signals, that enable GPS receivers to determine their location, speed, direction, and time. Following, the shooting down of Korean Air Lines Flight 007 in 1983. President Ronald Reagan issued a directive making the system available free for civilian use as a common good. Since then, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, scientific uses, and hobbies such as geocaching. GPS also provides a precise time reference used in many applications including scientific study of earthquakes, and synchronization of telecommunications networks.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.3
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• pp.421-428
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• 2021

Identifying which international maritime legal instruments are mandatory or recommendatory is complicated task even for maritime regulatory bodies. Although International Maritime Organization (IMO) had tried to ease the complexity by adopting guidelines on uniform wordings for making reference to other instruments in IMO parent conventions, there has still been some confusion identifying the mandatory status of IMO instruments. The aim of this study was to map out a step-based guideline to resolve the complexity of the mandatory status of IMO instruments to the maximum extent possible. This study reviewed the history of IMO rule-making process to find the root cause of the problem, then analyzed the approaches of regulatory enforcement bodies to check the practices. In conclusion, readers are directed to find such information as to legal status of IMO instruments and an improvement is proposed to enhance the transparency of information sharing for maritime industry to make better informed decisions.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.119-124
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• 1993

This paper describes a method of producing maps of an indoor environment with an autonomous mobile robot equipped with sonar array. This method uses the certainty grid suitable for accommodation of inaccurate sensor data and real-time navigation. Each grid contains a certainty vale that indicates the measure of confidence that an obstacle exists within th grid area. The scheduled firing method is used to eliminate the crosstalk between ultrasonic sensors. The effectiveness of the method is verified by a series of experiments.