• KIPS Transactions on Software and Data Engineering
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• v.7 no.1
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• pp.9-18
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• 2018

Recently, the use of image stitching technology has been increasing as the number of contents based on virtual reality increases. Image Stitching is a method for matching multiple images to produce a high resolution image and a wide field of view image. The image stitching is used in various fields beyond the limitation of images generated from one camera. Image Stitching detects feature points and corresponding points to match multiple images, and calculates the homography among images using the RANSAC algorithm. Generally, corresponding points are needed for calculating conversion relation. However, the corresponding points include various types of noise that can be caused by false assumptions or errors about the conversion relationship. This noise is an obstacle to accurately predict the conversion relation. Therefore, RANSAC algorithm is used to construct an accurate conversion relationship from the outliers that interfere with the prediction of the model parameters because matching methods can usually occur incorrect correspondence points. In this paper, we propose an algorithm that extracts more accurate inliers and computes accurate transformation relations by using correspondence point relation information used in RANSAC algorithm. The correspondence point relation information uses distance ratio between corresponding points used in image matching. This paper aims to reduce the processing time while maintaining the same performance as RANSAC.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.584-597
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• 2015

A considerable amount of literature has been published on pedestrian LOS. So far, however, there is a limitation that LOS analysis methodologies has concentrated on quantitative variables such as pedestrian flow rate, speed and space. This paper intended to suggest the accessibility variable which can not be considered on previous study. The factor was defined and quantified using public transport attributes in particular. This study was carried out in three phases: 1. defined accessibility employing public mode location and service information. 2. investigated the relationship between accessibility and pedestrian flow rate 3. developed the model to establish the factors affected to pedestrian LOS. The results showed that accessibility, walkway attribute and land use type affected the pedestrian LOS. Especially, accessibility and commercial area ratio had negative relationship with LOS. Futhermore, pedestrian LOS declined when obstacle of bus station located on the walkway. On the contrary, LOS was upgraded when sufficient effective width or residential area was secured. These results can receive considerable critical attentions related to determination of pedestrian LOS or effective walkway width.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.97-111
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• 2009

Image-based traffic information collection systems have entered widespread adoption and use in many countries since these systems are not only capable of replacing existing loop-based detectors which have limitations in management and administration, but are also capable of providing and managing a wide variety of traffic related information. In addition, these systems are expanding rapidly in terms of purpose and scope of use. Currently, the utilization of image processing technology in the field of traffic accident management is limited to installing surveillance cameras on locations where traffic accidents are expected to occur and digitalizing of recorded data. Accurately recording the sequence of situations around a traffic accident in a signal intersection and then objectively and clearly analyzing how such accident occurred is more urgent and important than anything else in resolving a traffic accident. Therefore, in this research, we intend to present a technology capable of overcoming problems in which advanced existing technologies exhibited limitations in handling real-time due to large data capacity such as object separation of vehicles and tracking, which pose difficulties due to environmental diversities and changes at a signal intersection with complex traffic situations, as pointed out by many past researches while presenting and implementing an active and environmentally adaptive methodology capable of effectively reducing false detection situations which frequently occur even with the Gaussian complex model analytical method which has been considered the best among well-known environmental obstacle reduction methods. To prove that the technology developed by this research has performance advantage over existing automatic traffic accident recording systems, a test was performed by entering image data from an actually operating crossroad online in real-time. The test results were compared with the performance of other existing technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.118-124
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• 2017

In this study, a numerical simulation was performed using commercial code Fluent(v.17.1). The underground Combined Cycle Power Plant (CCPP) was simplified to analyze the methane gas leakage with the crack size and position. In addition, extensive numerical simulations were carried out for different crack sizes from 10 mm to 20 mm. The crack position is the gas leakage, which is assumed to be near the pipe elbow and the gas turbine. A total of 4 cases were compared and analyzed. To analyze the gas leakage, the concept of the Lower Flammable Limit (LFL) was applied. The leakage distance was defined in the longitudinal direction, and the transverse direction was estimated and quantitatively analyzed. As a result, the leakage distance in the longitudinal direction varies by 52.3 % depending on the crack size at the same crack position. Moreover, the maximum difference was 34.8 % according to the crack position when the crack sizes are identical. As jet flow impacts on the obstacle and changes its direction, the recirculation flows are formed. These results are expected to provide useful data to optimize the location and number of gas detections in confined spaces, such as underground CCPP.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.228-234
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• 2001

Objective : The goal of this study was to identify variables that were predictive of recurrence in primary intracranial ependymomas. Methods : We analyzed variables affecting recurrence in 30 patients with primary intracranial ependymomas. Age, location, CSF cytology, seeding on neuroimaging study, tumor grade, extent of surgery, use of chemotherapy, chemotherapy regimen, use of radiotherapy, and radiotherapy field were entered to test their impacts on recurrence. Results : Follow-up ranged from 2 to 110 months. Tumors were recurred at the primary tumor site only in 13 patients (43.3%). The overall average recurrence free period was 55 months, with overall recurrence free rates at 3 and 6 years of 61.0% and 20.9%, respectively. Extent of surgery was the strongest variable affecting recurrence. The median recurrence free period and 3-year recurrence free rate were 72 months and 78.4% for patients having complete excision and 33 months and 0% for those having incomplete excision(p=0.05). Other prognostic variables like age, location, tumor grade, use of chemotherapy, and use of radiotherapy did not affect recurrence(p=0.2848, 0.7899, 0.1714, 0.2157, 0.7076, respectively). Conclusions : Intracranial ependymomas have a propensity to recur after treatment, and recurrence at the primary site is still the main obstacle to cure. Among various variables, only extent of resection had the strongest impact on recurrence. Additional studies may still be needed to precisely define the prognostic variables on recurrence in intracranial ependymomas.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.10
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• pp.465-472
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• 2015

We propose a novel plane detection in disparity space and evaluate its performance. Our method simplifies and makes scenes in disparity space easily dealt with by approximating various surfaces as planes. Moreover, the approximated planes can be represented in the same size as in the real world, and can be employed for obstacle detection and camera pose estimation. Using a stereo matching technique, our method first creates a disparity image which consists of binocular disparity values at xy-coordinates in the image. Slants of disparity values are estimated by exploiting a line simplification algorithm which allows our method to reflect global changes against x or y axis. According to pairs of x and y slants, we label the disparity image. 4-connected disparities with the same label are grouped, on which least squared model estimates plane parameters. N plane models with the largest group of disparity values which satisfy their plane parameters are chosen. We quantitatively and qualitatively evaluate our plane detection. The result shows 97.9%와 86.6% of quality in our experiment respectively on cones and cylinders. Proposed method excellently extracts planes from Middlebury and KITTI dataset which are typically used for evaluation of stereo matching algorithms.

• Cross-Cultural Studies
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• v.39
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• pp.241-286
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• 2015

This study explores how folktales' motifs are used in diverse cultural contents such as literature, movies, or comics. More precisely, it is concerned with mysterious characters like Babayaga and Koshchei who appear in Russian fairytales. When the motifs of the reviewed literature are analyzed, the following three criteria are used for classification: New Writing, Rewriting, and New Version. Or course, it is New Writing that is far from the original work. Most of the collected works, including Joan Aiken's The Kingdom Under the Sea, Patricia Polacco's Babushka's Doll, Babushka Baba Yaga, and Tai?-Marc Le Thanh's BABAYAGA, belong to New Writing. The New Writing type mainly focuses on Babayaga's secluded life. In fairytales, Babayaga is depicted as the goddess of Mother Earth, the heroine of the Nature, or the ruler of the Animal Kingdom. That is why she lives in the deep and uninhabited wood. She is related to the Coming of Age ceremony. Her 'Hut on hen's legs' is an obstacle for immature protagonists to face before they come of age. Protagonists are supposed to solve the problems posed by Babayaga. If they succeed, they can get her magical help so as to complete their final mission. Babayaga is likely to appear as their antagonist. Protagonist may be subjected to a terrible ordeal created by Babayaga, and then come of age by recovering from that ordeal. Sometimes, Babayaga helps protagonists to get a grip on reality. That is why she lives in a hut in the deep and dark forest which is on the borderline between life and death. On the other hand, Marianna Mayer's Baba Yaga and Vasilisa the Brave has been classified as a controversial work between New Writing and Rewriting. It is apparently closer to New Version. However, it cannot be classified as a work of New Version because the author incorporates 'probability' into her work. Among the reviewed works, it is Korean Writer Rye, Kami's The Spider Woman's House that best reflects the essence of Babayaga. Babayaga and other characters are amusing in movies because most of the movies are animations for children. In one sense, it is positive that the scary characters in folktales are approachable to children. In other sense, however, it is regrettable that symbolic motifs are completely eliminated. In Mike Mignola's Hellboy, Japanese animations such as Index or Narutaru, on-line games such as Cabal or Vampire: The masquerade, the essence of the supernatural characters in folktales is completely eliminated, and only their 'belligerent power' stands out. It is desirable to put stories into perspective whether they are written or told. The literature property of folktales provides a special opportunity to readers. In this light, a variety of motifs have a good reason to be reborn as modern cultural contents. The bottom line is to maintain its true nature.

• Korean Journal of Remote Sensing
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• v.22 no.4
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• pp.265-274
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• 2006

Extracting ground points is the kernel of DTM generation being considered as one of the most popular LIDAR applications. The previous extraction approaches can be mostly characterized as a point based approach, which sequentially examines every individual point to determine whether it is measured from ground surfaces. The number of examinations to be performed is then equivalent to the number of points. Particularly in a large set, the heavy computational requirement associated with the examinations is obviously an obstacle to employing more sophisticated criteria for the examination. To reduce the number of entities to be examined and produce more robust results, we developed an approach based on features rather than points, where a feature indicates an entity constructed by grouping some points. In the proposed approach, we first generate a set of features by organizing points into surface patches and grouping the patches into surface clusters. Among these features, we then attempt to identify the ground features with the criteria based on the attributes of the features. The points grouped into these identified features are labeled ground points, being used for DTM generation afterward. The Proposed approach was applied to many real airborne LIDAR data sets. The analysis on the results strongly supports the prominent performance of the proposed approach in terms of not only the computational requirement but also the quality of the DTM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.415-424
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• 2019

In this paper, a minimum rotation radius was designed and fabricated to overcome the threshold so that elderly or disabled people who have difficulty moving can move and transfer safely and conveniently in a narrow room. In the indoor environment, where the sedentary culture develops, this study aimed to provide convenience for passengers with fracture diseases, geriatric diseases, and other knee and waist diseases. First, links, seats, armrests, covers, motors, batteries, chargers, controllers, etc. were attached to the frame so that they could be moved and lifted indoors. The product design and structure were designed considering the user's environment and physical characteristics, and IoT functions were added. A driving experiment was performed to confirm the operating performance of the manufactured indoor moving and lifting wheelchair. The performance tests, such as continuous running time, turning radius, maximum actuator load, maximum lift height, sound pressure level, minimum sensing distance of the driving aid sensor, interworking of server and app programs, device compatibility, and duty cycle error rate, were performed. As a result of the test, the built-in wheelchair could achieve the performance test target of each item and operate successfully.

• The Journal of Natural Sciences
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• v.12 no.1
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• pp.85-101
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• 2002

Landscape civilization in Korea originated in Cochosun(Ancient Chosun) era, this again succeeding to the period of the Three States - Koguryo, Baekje and Silla. The distribution of this culture showed great progress with the association of two particular religions - Buddhism and Confucianism.. Landscape development in Korea has greatly changed during specific times of both cultural and political upheaval in various societies. Religion has had a great deal of influence on landscape development. Traditionally Korean people have had a tendency to favor more natural landscape than man-made structures in landscape : This trend was a quite different concept from that of other oriental countries, not to mention of western countries. In particular, Buddhism influenced natural landscape, far from artificial craftsmanship in landscape. Oriental garden is a typical 'tabloid edition' of natural landscape which consists lakes, islands, ponds, stone monuments, and fruit trees, quite often raising animal in parks and courtyard style house. This style of garden influenced in Chosun Dynasty landscape. Landscaping was usually for royal gardens, cemetery parks or high level of officer's residence. However, landscaping in Chosun Dynasty which had established Confucianism as a state religion gave us a specific designation. It was neither ethnic imitation of the garden style of both China and Japan : People were used to enjoy nature-friendly landscape or sink into the ecstasy of natural scenery itself. The trend that landscape or establishing garden had been aimed at royal family- or bureaucrat-centered formatives was to become an obstacle to the development of landscape techniques in Korea. An example represented in a beautiful garden with fabulous decoration which established in places. This was completely not fit for the nation's feeling.