• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.174-174
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• 2000

Q-learning, based on discrete state and action space, is a most widely used reinforcement Learning. However, this requires a lot of memory and much time for learning all actions of each state when it is applied to a real mobile robot navigation using continuous state and action space Region-based Q-learning is a reinforcement learning method that estimates action values of real state by using triangular-type action distribution model and relationship with its neighboring state which was defined and learned before. This paper proposes a new Region-based Q-learning which uses a reward assigned only when the agent reached the target, and get out of the Local optimal path with adjustment of random action rate. If this is applied to mobile robot navigation, less memory can be used and robot can move smoothly, and optimal solution can be learned fast. To show the validity of our method, computer simulations are illusrated.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1254-1257
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• 1993

Presented in this paper is a newly developed motion planning method of an autonomous mobile robot(MAR) which can be applied to flexible manufacturing systems(FMS). The mobile robot is designed for transporting tools and workpieces between a set-up station and machines according to production schedules of the whole FMS. The proposed method is implemented based on an earlier developed real-time obstacle avoidance method which employs Kohonen network for pattern classification of sonar readings and fuzzy logic for local path planning. Particulary, a novel obstacle avoidance method for moving objects using a collision index, collision possibility measure, is described. Our method has been tested on the SNU mobile robot. The experimental results show that the robot successfully navigates to its target while avoiding moving objects.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.2
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• pp.103-134
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• 1998

This paper examined the evolution and development strategies of Young-deung Festival holding in Chindo since 1978. The Young-deung Festival is a representative event tourism in Korea. The water between Hoidong and Modo in Chindo, a small islet 2.8km off the coast, part to reveal a path 40m wide as a result of the moon influence on the tides. This phenomenon is called “young-deung-sal”on the Chindo. This event began on a small scale highlighting the treasury of traditional folkfore and shamanism peculiar to these islands, various cultural resources, and local place attraction such as young-deung-sal. But, in the early 1990s, with the introduction of systematic management and a variety of programs, the small village festival has steadily evloved in the scale aspects of the program, budget, profit, and the number of visitors participating in festival. In addition, the period of festival was prolonged for three days and visitors from other provinces have steadily increased, in particular visitors from Seoul and Gyoungkee have steadily increased. In order to develop the Young-deung Festival, the followings should be done: creation of local image through place attraction, private organization in supporting festival, adoption of management techniques for the local economic activites, and extension of linkage with tourists places around Chindo, target visitor marketing through a continuous visitor survey.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.5-25
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• 2009

In recent years the popularity of multi-hop wireless networks has been growing. Its flexible topology and abundant routing path enables many types of applications. However, the lack of a centralized controller often makes it difficult to design a reliable service in multi-hop wireless networks. While packet routing has been the center of attention for decades, recent research focuses on data discovery such as file sharing in multi-hop wireless networks. Although there are many peer-to-peer lookup (P2P-lookup) schemes for wired networks, they have inherent limitations for multi-hop wireless networks. First, a wired P2P-lookup builds a search structure on the overlay network and disregards the underlying topology. Second, the performance guarantee often relies on specific topology models such as random graphs, which do not apply to multi-hop wireless networks. Past studies on wireless P2P-lookup either combined existing solutions with known routing algorithms or proposed tree-based routing, which is prone to traffic congestion. In this paper, we present two wireless P2P-lookup schemes that strictly build a topology-dependent structure. We first propose the Ring Interval Graph Search (RIGS) that constructs a DHT only through direct connections between the nodes. We then propose the ValleyWalk, a loosely-structured scheme that requires simple local hints for query routing. Packet-level simulations showed that RIGS can find the target with near-shortest search length and ValleyWalk can find the target with near-shortest search length when there is at least 5% object replication. We also provide an analytic bound on the search length of ValleyWalk.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.137-145
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• 2016

A novel tracking method is proposed to find coronary artery using high-order curve model in coronary CTA(Computed Tomography Angiography). The proposed method quickly generates numerous artificial trajectories represented by high-order curves, and each trajectory has its own cost. The only high-ranked trajectories, located in the target structure, are selected depending on their costs, and then an optimal curve as the centerline will be found. After tracking, each optimal curve segment is connected, where optimal curve segments share the same point, to a single curve and it is a piecewise smooth curve. We demonstrated the high-order curve is a proper model for classification of coronary artery. The experimental results on public data set sho that the proposed method is comparable at both accuracy and running time to the state-of-the-art methods.

• Journal of Korea Water Resources Association
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• v.49 no.7
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• pp.579-588
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• 2016

Changes in precipitation due to climate change is made to induce the local and intensive rainfall, it is increasing damage caused by inland inundation. Therefore, it requires a technique for predicting damage caused by flooding. In this study, in order to determine whether this flood inundated by any route when the levee was destroyed, Which can simulate the path of the flood inundation model was developed for the SIMOD (Simplified Inundation MODel). Multi Direction Method (MDM) for differential distributing the adjacent cells by using the slope and Flat-Water Assumption (FWA)-If more than one level higher in the cell adjacent to the cell level is the lowest altitude that increases the water level is equal to the adjacent cells- were applied For the evaluation of the model by setting the flooding scenarios were estimated hourly range from the target area. SIMOD model can significantly reduce simulation time because they use a simple input data of topography (DEM) and inflow flood. Since it is possible to predict results within minutes, if you can only identify inflow flood through the runoff model or levee collapse model. Therefore, it could be used to establish an evacuation plan due to flooding, such as EAP (Emergency Action Plan).

• Journal of Digital Convergence
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• v.15 no.2
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• pp.173-181
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• 2017

In this paper, we have studied tracking as a training stage of considering the position and the scale of a person given its previous position, scale, as well as next and forward image fraction. Unlike other learning methods, CNN is thereby learning combines both time and spatial features from the image for the two consecutive frames. We introduce multiple path ways in CNN to better fuse local and global information. A creative shift-variant CNN architecture is designed so as to alleviate the drift problem when the distracting objects are similar to the target in cluttered environment. Furthermore, we employ CNNs to estimate the scale through the accurate localization of some key points. These techniques are object-independent so that the proposed method can be applied to track other types of object. The capability of the tracker of handling complex situations is demonstrated in many testing sequences. The accuracy of the SVM classifier using the features learnt by the CNN is equivalent to the accuracy of the CNN. This fact confirms the importance of automatically optimized features. However, the computation time for the classification of a person using the convolutional neural network classifier is less than approximately 1/40 of the SVM computation time, regardless of the type of the used features.

• Analytical Science and Technology
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• v.28 no.4
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• pp.288-298
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• 2015

A distribution study of glitter was conducted from a local university building. The potential recipient surfaces chosen were the 1,000 chairs kept in 16 separate classrooms of the building. The surface of chairs contacting with buttocks and back of users were tape lifted with commercial adhesive tapes, and the surface of adhesive tapes were examined with a stereomicroscope to locate the glitters. 12 glitter particles were found from 11 chairs kept in 16 classrooms of a building. This result indicates that the possibility of glitter finding from Korean violent crime scene is high. The 12 glitters found from the chairs were analyzed with a stereomicroscope and an FTIR spectrophotometer to find the matching glitter. The stereomicroscope was used for the observation of the shapes, dimensions, colors and holograms of each glitter, and the FTIR spectrophotometer was used for the analysis of the chemical composition of the coating material of each glitter. The examination results revealed that 8 glitters out of 12 glitters were not sharing the common origin each other. Also, two glitters found from two separate classroom chairs share common microscopic and FTIR spectroscopic characteristics which indicating two glitters share common origin. The record of the students who had used the classrooms was traced and the authors could find that the classrooms where the same glitters were found were shared by a group of students who listen to the same class. This result implies that the path of the involved people should be considered while assessing the value of trace evidence.

• Journal of Environmental Impact Assessment
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• v.24 no.2
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• pp.134-153
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• 2015

When making urban planning, it is important to understand climate effect caused by urban structural changes. Seoul city applies UPIS(Urban Plan Information System) which provides information on urban planning scenario. Technology for analyzing climate effect resulted from urban planning needs to developed by linking urban planning scenario provided by UPIS and climate analysis model, CAS(Climate Analysis Seoul). CAS develops for analyzing urban climate conditions to provide realistic information considering local air temperature and wind flows. Quantitative analyses conducted by CAS for the production, transportation, and stagnation of cold air, wind flow and thermal conditions by incorporating GIS analysis on land cover and elevation and meteorological analysis from MetPhoMod(Meteorology and atmospheric Photochemistry Meso-scale model). In order to reflect land cover and elevation of the latest information, CAS used to highly accurate raster data (1m) sourced from LiDAR survey and KOMPSAT-2(KOrea Multi-Purpose SATellite) satellite image(4m). For more realistic representation of land surface characteristic, DSM(Digital Surface Model) and DTM(Digital Terrain Model) data used as an input data for CFD(Computational Fluid Dynamics) model. Eight inflow directions considered to investigate the change of flow pattern, wind speed according to reconstruction and change of thermal environment by connecting green area formation. Also, MetPhoMod in CAS data used to consider realistic weather condition. The result show that wind corridors change due to reconstruction. As a whole surface temperature around target area decreases due to connecting green area formation. CFD model coupled with CAS is possible to evaluate the wind corridor and heat environment before/after reconstruction and connecting green area formation. In This study, analysis of climate impact before and after created the green area, which is part of 'Connecting green network across the north and south in Seoul' plan, one of the '2020 Seoul master plan'.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.3
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• pp.59-66
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• 2023

This study attempts to examine the process of establishing a Japanese-style garden in the modern period through the perspectives of garden designers, spatial composition, spatial components, and materials used in their works, and to use it as data for embodying the identity of Korean garden. The results are as follows: First, by incorporating elements associated with Koreanness into the modern garden culture, there are differences in location, presence, and subjectivity when compared to Japan. This reflects Japan's relatively seamless cultural continuity compared to Korea's cultural disconnection during the modern period. Second, prior to the modern period, Japan's garden culture spread and continued to develop throughout the country without significant interruptions. However, during the modern period, the Meiji government promoted the policy of 'civilization and enlightenment (Bunmei-kaika, 文明開化)' and introduced advanced European and American civilizations, leading to the popularity of Western-style architectural techniques. Unfortunately, the rapid introduction of Western culture caused the traditional Japanese culture to be overshadowed. In 1879, British architect Josiah Condor guided Japanese architects and introduced atelier and traditional designs of Japanese gardens into the design. The garden style of Ogawa Jihei VII, a garden designer in Kyoto during the Meiji and Taisho periods, was accepted by influential political and business leaders who sought to preserve Japan's traditional culture. And a protection system of garden was established through the preparation of various laws and regulations. Third, as a comprehensive analysis of Japanese modern gardens, the examination of garden designers, Japanese components, materials, elements, and the Japanese-style showed that Yamagata Aritomo, Ogawa Jihei VII, and Mirei Shigemori were representative garden designers who preserved the Japanese-style in their gardens. They introduced features such as the creation of a Daejicheon(大池泉) garden, which involves a large pond on a spacious land, as well as the naturalistic borrowed scenery method and water flow. Key components of Japanese-style gardens include the use of turf, winding garden paths, and the variation of plant species. Fourth, an analysis of the Japanese-style elements in the target sites revealed that the use of flowing water had the highest occurrence at 47.06% among the individual elements of spatial composition. Daejicheon and naturalistic borrowed scenery were also shown. The use of turf and winding paths were at 65.88% and 78.82%, respectively. The alteration of tree species was relatively less common at 28.24% compared to the application of turf or winding paths. Fifth, it is essential to discover more gardens from the modern period and meticulously document the creators or owners of the gardens, the spatial composition, spatial components, and materials used. This information will be invaluable in uncovering the identity of our own gardens. This study was conducted based on the analysis of the process of establishing the Japanese-style during Japan's modern period, utilizing examples of garden designers and gardens. While this study has limitations, such as the absence of in-depth research and more case studies or specific techniques, it sets the stage for future exploration.