• Journal of the Korea Computer Graphics Society
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• v.17 no.3
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• pp.1-7
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• 2011

Recently, various researches have been proposed to accelerate GPU-based volume ray-casting. However, those researches may cause several problems such as bottleneck of data transmission between CPU and GPU, requirement of additional video memory for hierarchical structure and increase of processing time whenever opacity transfer function changes. In this paper, we propose an efficient GPU-based empty space skipping technique to solve these problems. We store maximum density in a brick of volume dataset on a vertex element. Then we delete vertices regarded as transparent one by opacity transfer function in geometry shader. Remaining vertices are used to generate bounding boxes of non-transparent area that helps the ray to traverse efficiently. Although these vertices are independent on viewing condition they need to be reproduced when opacity transfer function changes. Our technique provides fast generation of opaque vertices for interactive processing since the generation stage of the opaque vertices is running in GPU pipeline. The rendering results of our algorithm are identical to the that of general GPU ray-casting, but the performance can be up to more than 10 times faster.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.487-496
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• 2009

This paper addresses an indexing scheme capable of efficiently processing range queries in a large-scale trajectory database. After discussing the drawbacks of previous indexing schemes, we propose a new scheme that divides the temporal dimension into multiple time intervals and then, by this interval, builds an index for the line segments. Additionally, a supplementary index is built for the line segments within each time interval. This scheme can make a dramatic improvement in the performance of insert and search operations using a main memory index, particularly for the time interval consisting of the segments taken by those objects which are currently moving or have just completed their movements, as contrast to the previous schemes that store the index totally on the disk. Each time interval index is built as follows: First, the extent of the spatial dimension is divided onto multiple spatial cells to which the line segments are assigned evenly. We use a 2D-tree to maintain information on those cells. Then, for each cell, an additional 3D $R^*$-tree is created on the spatio-temporal space (x, y, t). Such a multi-level indexing strategy can cure the shortcomings of the legacy schemes. Performance results obtained from intensive experiments show that our scheme enhances the performance of retrieve operations by 3$\sim$10 times, with much less storage space.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.351-359
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• 2019

Neurocognitive testing commonly uses the MMSE (Mini-Mental State Examination) to evaluate the overall cognitive function of patients at outpatient clinics, but the MMSE has recently been extensively used in the SNSB II (Seoul Neuropsychological Screening Battery II) for making diagnoses. We retrospectively investigated the results of routine neurocognitive tests and the results of the blood tests of 120 elderly patients who had been referred to a South Central Medical Center from 2017 to 2018 and who had been examined at a public health center. These subjects' space-time capability was high on the sub-region of the global deterioration scale (GDS). GDS showed a significant increase as the Na decreased on the electrolyte analysis. The subjects' concentration, their language-based orientation for space and time, their memory, and their scores for the frontal lobe function on GDS showed statistically significant reductions (P<0.001) For the normal and abnormal groups according to the ALT and creatinine levels, the frontal/execute function areas showed statistically significant differences (P<0.001) as well as negative correlation between GDS and ALT (P<0.01). In conclusion, this study provides basic information to develop test items that are important for patient screening and diagnosis, and several routine blood chemistry factors provide basic information for diagnosing and assessing the status and progress of cognitively impaired patients.

• Journal of Popular Narrative
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• v.26 no.2
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• pp.191-219
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• 2020

This paper aims to identify the key features of the novel writing of Korean American immigrants and their meaning as one aspect of movement and contact occuring in the early modern period. The late return of the novels written by Nakcheong THUN in the 1930s is significant in that it restored ideas on the diversity of early modern mobility and confronted the history and culture of immigrants who were excluded from records and memories. Not only are these novels a product of the phenomenon of immigration, but they have also created a crack in the dichotomous perceptions of domination and subordination, center and periphery by envisioning it as a space that creates new history, culture, institutions and values. These novels treat the free love of intellectual, emotional, and ethical figures as a central event, demystifying Western free love, and at the same time, a society divided by various identities including class, race, and gender. The novels by Nakchung THUN visualize the active exchange between the immigrant and the indigenous community through the character of Jack, and imagines the heterotopia as a place where not for the immigrants' utopia, but for everyone's coexists. These novels have declared a kind of memory war on the subordinate and marginalized contact zones. The contact zones of the immigration area had been a place for experiencing extreme conflicts and discords, and at the same time, it has served as a place where various groups and communities are connected. The contact zones were common areas of solidarity and creation before being subject to division and occupation. The contact zones are far from the border or borderlands, so it is not a fixed and immutable deadlock. As a world free from central domination the contact zones have been a space that preoccupied history and culture through various encounters, and have been a community.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.72-85
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• 2009

This study attempts to examine the principles of landscape composition for a 'Suhwon(書院)' and the meaning and value of its traditional landscape architecture, in order to apply the results to the design of modern landscape architecture. A 'Suhwon' is a vital space containing the form and meaning of human activity. This study analyzes the characteristics of landscape composition in the construction of the Namgea Suhwon, located in Hamyang, by examining the form and meaning of its area and composition. The Namgea Suhwon was constructed with a suitable configuration and harmony in a good location, neither field nor mountain, and which encompasses transcendence and a return after passage through a period of birth and abundance. Its appearance means 'life existence and hidden death(生居死幽)'. Its spatial system is a reflection of the idea of Samshinoje(三神五帝: The three abilities of Providence and its five subjects) connected with Ilsangje -Samshin -Ohje. It was built based on the idea of Biryebudong(非禮不動) meaning that one should follow only good decorum and avoid discourtesy, complying with "the frame of decorum" developed by the family rites of Chu Hsi. The environmental design of the Namgea Suhwon was interrupted by the material confrontation between mountains and water and a binary code system, such as front to rear, length to breadth, and movement to stillness. The design did not adhere to stiff axes, but pursued the harmonic principles of asymmetric balance in the building and the yard, which are very naturalistic. The name 'Namgea Suhwon' is closely related with the view of placement(置) and harmony(和), which are unified with the function and meaning formed by connecting Sung Confucianism with the Pungsu-Sasinsa structure in the layout of the grounds. When examining the D/H ratio of the building and yard, it can be seen that the spaces of Ganghak, Yusang and Jehyang were built appropriately, according to the natural characteristics of each space, such as a sense of openness, enclosure, tension, relief, enhancement, and hierarchical order. The spaces also reflect human scale concepts that take advantage of auditory features. The transition process after the construction of 'Namgea Suhwon' reveals the intentions of the builder to create an ecological landscape composition based on Placement and Harmony. Placement embodies' a purposeful space in which nature and the building are connected naturally, 'incomplete open space pursuing completion', and 'potential beauty in which tension and relaxation are repeated'. Harmony embodies 'order and continuity having a sense of unity with the natural environment' and the 'sharing of daily life and memory'. 'Namgea Suhwon' contains many ideas for landscape planning, land use and the design of a campus environment.

• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.67-81
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• 2005

Recently, the interest and research on the development of new application services such as the Location Based Service and Telemetics providing the emergency service, neighbor information search, and route search according to the development of the Geographic Information System have been increasing. User's search in the spatio-temporal database which is used in the field of Location Based Service or Telemetics usually fixes the current time on the time axis and queries the spatial and aspatial attributes. Thus, if the range of query on the time axis is extensive, it is difficult to efficiently deal with the search operation. For solving this problem, the snapshot, a method to summarize the location data of moving objects, was introduced. However, if the range to store data is wide, more space for storing data is required. And, the snapshot is created even for unnecessary space that is not frequently used for search. Thus, non storage space and memory are generally used in the snapshot method. Therefore, in this paper, we suggests the Hash-based Spatio-Temporal Clustering Algorithm(H-STCA) that extends the two-dimensional spatial hash algorithm used for the spatial clustering in the past to the three-dimensional spatial hash algorithm for overcoming the disadvantages of the snapshot method. And, this paper also suggests the knowledge extraction algorithm to extract the knowledge for the path search of moving objects from the past location data based on the suggested H-STCA algorithm. Moreover, as the results of the performance evaluation, the snapshot clustering method using H-STCA, in the search time, storage structure construction time, optimal path search time, related to the huge amount of moving object data demonstrated the higher performance than the spatio-temporal index methods and the original snapshot method. Especially, for the snapshot clustering method using H-STCA, the more the number of moving objects was increased, the more the performance was improved, as compared to the existing spatio-temporal index methods and the original snapshot method.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.2
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• pp.40-53
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• 2019

This study was conducted to investigate the changes in Scenic Spots by utilizing the "Sinjeungdonggukyeojiseungram(新增東國輿地勝覽)" and "Joseonhwanyeoseungnam(朝鮮?與勝覽)" to interpret "Joseonmyeongseungsiseon(朝鮮名勝詩選, 1915)". By examining the historical context when "Joseonmyeongseungsiseon" was published, it documented the Japanese's memories of 'Sino-Japanese War(淸日戰爭)' in 1894, which implies the 'policy of assimilation' by the Japanese Government-General of Korea after the Japanese annexation of Korea(1910). Detailed information about the author 'Narushima Sagimura(成島鷺村)' can be found in preface. In the "Joseonmyeongseungsiseon", it dedicates most of the part in describing the Scenic Spot especially in 'Anseong Do (15 lines)', where has the memories of war such as the 'First Sino-Japanese War'. The number of Scenic Spots, commonly mentioned in both "Sinjeungdonggukyeoji seungram" and "Joseonhwanyeoseungnam" in Cheonan province are 13 in total. Most of the content contains a similar structure. But 'Honggyeongwon(弘慶院)' and 'Seonghwanyeok(成歡驛)' has both the common Joseon Dynasty landscape point of view, and the additional historical context which are about the 'Jeongyujaeran(丁酉再亂)' or 'First Sino-Japanese War' consequently enlightens the 'placeness' of the Scenic Spots. Among the newly described Scenic Spots, 'Anseongdo(安城渡)' is the part that focuses on the memory of the 'Anseongcheon Battle' that gave Japan its first defeat in the Sino-Japanese War. Especially, by introducing the poetry of 'Sinobu Shunpei' it maximizes the appreciation through emphasizing the direct correlation between placeness and the poem itself. While the Joseon Dynasty poems are 10 pieces in total and their title and the subject matters are all related to historical spots, and the appreciation also maximizes when fully interpreted with understanding the historical context. However, it's contextual meanings are neglected by dividing the actual structures into separate pages. When looking at the location of famous historic sites, they come in many different types, considering the location, meaning, size, and conditions surrounding them. It appears as a service space for travelers, a place for sightseeing, relaxation or return, a temple space for paying respects or memorial services, a fortress facility for defense and protection, or a fishing area for wages, and an old battlefield. Especially, it is noted that the area is diverse as the cultural landscape of Cheonan, given that the battle space between the hermitage and the Donghangnongmin(東學農民) is shared with each other. It is necessary to establish policies for the preservation and restoration of local cultural assets based on these points in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.66-79
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• 2017

In 2014, a Donghak Peasant Revolution Memorial Park design competition was held with various forms and techniques to convey mourning. This is a process of the reconsideration of memorial projects that are used to stimulate the collective memory and it is a meaningful resource for examining the consciousness of contemporary designers in regards to the memorial designs that are currently under planning in Korea. This study investigated the background of the Donghak commemorative projects that took place at the same site in a timely manner and analyzed the design competition through the existing literature research. Through this, it was seen that the memorial, which was formed by means of past political purposes, has changed into a way to collect various opinions and forms through open design competition. A framework of analysis prepared through multi-layer analysis is daily use, interaction and spontaneity, abstraction, temporality, locality, integration and harmony with surroundings. The results of this study are as follows. First, in order to convey memorial commemoration in everyday life, the projects organized scattered memorial spaces with special characteristics and linked them with daily activities program. Second, the projects used direct participation and emotional experiences to interact with monuments. Third, color, vertical elements, clustering, and park frame manipulation were used for abstract reproduction. Fourth, the projects introduce architecture and furniture that can be changed and plants for temporal change. Fifth, the previous terrain was restored and the setting of the scene was reproduced in order to make the site a space with place. Sixth, to improve the connection with existing monuments, the projects used techniques such as relaxation and the reinforcement of circulation lines and axes. Seventh, a path and a building conforming to the terrain were arranged for harmony with the surroundings.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.77-83
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• 2015

Frequent pattern mining, which is one of the major areas actively studied in data mining, is a method for extracting useful pattern information hidden from large data sets or databases. Moreover, frequent pattern mining approaches have been actively employed in a variety of application fields because the results obtained from them can allow us to analyze various, important characteristics within databases more easily and automatically. However, traditional frequent pattern mining methods, which simply extract all of the possible frequent patterns such that each of their support values is not smaller than a user-given minimum support threshold, have the following problems. First, traditional approaches have to generate a numerous number of patterns according to the features of a given database and the degree of threshold settings, and the number can also increase in geometrical progression. In addition, such works also cause waste of runtime and memory resources. Furthermore, the pattern results excessively generated from the methods also lead to troubles of pattern analysis for the mining results. In order to solve such issues of previous traditional frequent pattern mining approaches, the concept of representative pattern mining and its various related works have been proposed. In contrast to the traditional ones that find all the possible frequent patterns from databases, representative pattern mining approaches selectively extract a smaller number of patterns that represent general frequent patterns. In this paper, we describe details and characteristics of pattern condensing techniques that consider the maximality or closure property of generated frequent patterns, and conduct comparison and analysis for the techniques. Given a frequent pattern, satisfying the maximality for the pattern signifies that all of the possible super sets of the pattern must have smaller support values than a user-specific minimum support threshold; meanwhile, satisfying the closure property for the pattern means that there is no superset of which the support is equal to that of the pattern with respect to all the possible super sets. By mining maximal frequent patterns or closed frequent ones, we can achieve effective pattern compression and also perform mining operations with much smaller time and space resources. In addition, compressed patterns can be converted into the original frequent pattern forms again if necessary; especially, the closed frequent pattern notation has the ability to convert representative patterns into the original ones again without any information loss. That is, we can obtain a complete set of original frequent patterns from closed frequent ones. Although the maximal frequent pattern notation does not guarantee a complete recovery rate in the process of pattern conversion, it has an advantage that can extract a smaller number of representative patterns more quickly compared to the closed frequent pattern notation. In this paper, we show the performance results and characteristics of the aforementioned techniques in terms of pattern generation, runtime, and memory usage by conducting performance evaluation with respect to various real data sets collected from the real world. For more exact comparison, we also employ the algorithms implementing these techniques on the same platform and Implementation level.

• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.25-53
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• 2017

The ultimate goal of this research is to examine the geographical characteristics of therapeutic spaces where have been appeared in Wa-dong and Gojan-dong, Ansan-si after the disaster of the MV Sewol. As looking into the inside, the aim of the therapeutic spaces, which cover each target group (victims) individually, is various and different because the disaster of the MV Sewol generated various direct and indirect victims requiring healing. The therapeutic spaces are estimated at about 10 organizations and are leaded by private agents predominantly. Furthermore, the therapeutic spaces are located near, but are aside from Danwon high school where many students are reported killed and injured in the incident. And the therapeutic spaces provide simple and repetitive diversions, for example, having a meal, knitting and studying, rather than special programs to restore a broken daily life to the original state. On the basis of such a background, the geographical characteristics of the therapeutic spaces related to the disaster of the MV Sewol can be summarized as follows; first, it seems that target groups accept the therapeutic spaces as the concept of place gradually. Even though most of the therapeutic spaces were suggested by third parties at first, target groups are involved in the management and recollection of their own therapeutic spaces as well as the plan for a future direction now; and consider the therapeutic spaces as exclusive properties. Second, the disaster of the MV Sewol have embedded collective trauma to not only direct victims, but extensive groups such as parents, brothers and sisters, relatives, friends and neighbors as noted earlier. Therefore, the therapeutic spaces support comprehensive target groups; but each therapeutic space is not overlapped each other. However, to solve collective trauma in a local community effectively, the therapeutic spaces are networked closely and build a regular cooperative system. Third, a continuous memory is mentioned as an important point to overcome collective trauma, but some phenomena such as fatigue and conflict with neighbors, out-migrants and a faded atmosphere as time passes act as risk factors in Ansan-si. To keep a continuous memory, the therapeutic spaces attempt the recovery of local communities and devise various events, for example, cultural performances; furthermore, are closely connected with external organizations.