• Information Systems Review
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• v.19 no.2
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• pp.1-19
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• 2017

Original scripts of e-learning lectures for the CEOs of corporation S were analyzed using topic analysis, which is a text mining method. Twenty-two topics were extracted based on the keywords chosen from five-year records that ranged from 2011 to 2015. Research analysis was then conducted on various issues. Promising topics were selected through evaluation and element analysis of the members of each topic. In management and economics, members demonstrated high satisfaction and interest toward topics in marketing strategy, human resource management, and communication. Philosophy, history of war, and history demonstrated high interest and satisfaction in the field of humanities, whereas mind health showed high interest and satisfaction in the field of in lifestyle. Studies were also conducted to identify topics on the proportion of content, but these studies failed to increase member satisfaction. In the field of IT, educational content responds sensitively to change of the times, but it may not increase the interest and satisfaction of members. The present study found that content production for CEOs should draw out deep implications for value innovation through technology application instead of simply ending the technical aspect of information delivery. Previous studies classified contents superficially based on the name of content program when analyzing the status of content operation. However, text mining can derive deep content and subject classification based on the contents of unstructured data script. This approach can examine current shortages and necessary fields if the service contents of the themes are displayed by year. This study was based on data obtained from influential e-learning companies in Korea. Obtaining practical results was difficult because data were not acquired from portal sites or social networking service. The content of e-learning trends of CEOs were analyzed. Data analysis was also conducted on the intellectual interests of CEOs in each field.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.1-10
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• 2013

RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.67-75
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• 2012

Purpose : We studied enhanced method to view the vessels in the brain using Magnetic Resonance Angiography (MRA). Noticing that Maximum Intensity Projection (MIP) image is often used to evaluate the arteries of the neck and brain, we propose a new method for view brain vessels to stereo image in 3D space with more superior and more correct compared with conventional method. Materials and Methods: We use 3T Siemens Tim Trio MRI scanner with 4 channel head coil and get a 3D MRA brain data by fixing volunteers head and radiating Phase Contrast pulse sequence. MRA brain data is 3D rotated according to the view angle of each eyes. Optimal view angle (projection angle) is determined by the distance between eye and center of the data. Newly acquired MRA data are projected along with the projection line and display only the highest values. Each left and right view MIP image is integrated through anaglyph imaging method and optimal stereoscopic MIP image is acquired. Results: Result image shows that proposed method let enable to view MIP image at any direction of MRA data that is impossible to the conventional method. Moreover, considering disparity and distance from viewer to center of MRA data at spherical coordinates, we can get more realistic stereo image. In conclusion, we can get optimal stereoscopic images according to the position that viewers want to see and distance between viewer and MRA data. Conclusion: Proposed method overcome problems of conventional method that shows only specific projected image (z-axis projection) and give optimal depth information by converting mono MIP image to stereoscopic image considering viewers position. And can display any view of MRA data at spherical coordinates. If the optimization algorithm and parallel processing is applied, it may give useful medical information for diagnosis and treatment planning in real-time.

• Archives of design research
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• v.16 no.4
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• pp.385-394
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• 2003

An investigation by KRNIC (Korea Network Information Center) on the real state of usage of internet has shown that 96.9％ of children investigated had experiences of using internet. Especially the firstly ranked item that had been answered by children as a necessity of internet was 'Studying to solve tasks' rated by 83.9％. As seen from the research result, the need as a homework sonics is actually so dominant that it cannot be ignored when considering the profitability at the area of education contents, but any profound research has not been accomplished yet. Internet has been positioned as a more effective and fruitful learning tool, and also all activities done by users for exploring informations and choosing learning items under the on-line circumstances are based on the successive mutual reactions between users and computers. Up to now much of the web based learning circumstances has been introducing the User Interface using metaphor, and the same is found dominantly from the sites for children. But in spite of the availability of metaphor mentioned above the current status is much lack of profound researches about metaphor interface; and what is more, in the case of the site for elementary school students the gap of the ability recognizing metaphor is very large between lower classes and higher classes according to the degree of mental growth but that is used to be simply ignored, then a common concept is adapted to interface for all grades of classes and moreover for infant and kindergarten without any objections. Based on foregoing problems this research has put the main focus on the groping and presenting desirable directions on the prospect design of interface for children-oriented sites by analyzing the status of practical usage of metaphor interface in the field of the sites for children-oriented learning sites with concentration upon homework supporting domains.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.555-562
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• 2004

Both global volume reduction and local shape changes of hippocampus within the brain indicate their abnormal neurological states. Hippocampal shape analysis consists of two main steps. First, construct a hippocampal shape representation model ; second, compute a shape similarity from this representation. This paper proposes a novel method for the analysis of hippocampal shape using integrated Octree-based representation, containing meshes, voxels, and skeletons. First of all, we create multi-level meshes by applying the Marching Cube algorithm to the hippocampal region segmented from MR images. This model is converted to intermediate binary voxel representation. And we extract the 3D skeleton from these voxels using the slice-based skeletonization method. Then, in order to acquire multiresolutional shape representation, we store hierarchically the meshes, voxels, skeletons comprised in nodes of the Octree, and we extract the sample meshes using the ray-tracing based mesh sampling technique. Finally, as a similarity measure between the shapes, we compute $L_2$ Norm and Hausdorff distance for each sam-pled mesh pair by shooting the rays fired from the extracted skeleton. As we use a mouse picking interface for analyzing a local shape inter-actively, we provide an interaction and multiresolution based analysis for the local shape changes. In this paper, our experiment shows that our approach is robust to the rotation and the scale, especially effective to discriminate the changes between local shapes of hippocampus and more-over to increase the speed of analysis without degrading accuracy by using a hierarchical level-of-detail approach.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.73-87
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• 2012

Nowadays, the Korean society is full of multiculturalism as there are many foreign ethnic enclaves. Many Chinese quarters are built in various parts of Korea along with the increasing population of Chinese immigrant. Especially, the Chinese quarter has shown the sign of time and the cultural characteristic of the local residents. This research is to study the market space of Chinese ethnic enclaves in Dairimdong. This research method is the field study to use a participant observation. Below are the research results: Chinese merchants put a private object such as "tanzi" on a sidewalk and install large awning covered full of sidewalk. Sidewalk transform from an outdoor space into an internal space because of Chinese merchants. Passers-by move to use vehicle roads and transform not only the car's space but also the passers-by space. Urban planners originally classify space into three categories, which are building - sidewalk - vehicles road. However, after Chinese came to the market, Chinese classified space into new three categories which is building - space for both sidewalk and "tanzi" - space for both sidewalk and vehicles road. New classification of space is quite different from the previous. In addition, Chinese thinks that the Dairimdong's Market is a very comfortable place. Because Dairimdong Market have many Chinese physical facilities. Next, Chinese thinks that the Dairimdong Market is a very friendly place to buy Chinese products easily. This market has become a place of consumption for the Chinese. Eventually, Dairimdong's Market has changed because of Chinese immigrants. It is possible to make satisfactory planning and design proposal to build Chinese quarters in the future through the explanation of space and status by way of culture. There are many careless mistakes in previous subjective planning and design proposal of the designers. Thus, it should consider the problems created by their way of use in later planning and design.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.155-160
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• 2005

Purpose : Many authors have been introduced field in field technique and 3-D conformal radiotherapy that increased the tumor dose as well as decreased the dose of abutting critical organ. These technique have multiple beam direction and small beam segments even below 10 MU(monitor unit)for each field. we have confirmed the influence of low MU on dose output and beam stability. Materials and Methods : To study the dose output, the dose for each field was always 90MU, but it divided into different segment size: 1, 2, 3, 5, 10, 15 segments, 90, 45, 30, 18, 9, 6 MU the measurements were carried out for X-ray energy 4 MV, 6 MV, 10 MV of three LINAC(Varian 600C, 2100C, 2100C, 2100C/D), in addition each measurement was randomly repeated three times for each energy. To study the field symmetry and flatness, X-omat V films were irradiated. After being developed, films were scanned and analyzed using densitometer. Results : Influence of low MU on dose is slightly more increase output about $1.2{\sim}2.9%$ in cGy/mu than 90MU, but may not changed beam quality(flatness or symmetry), Output stability depends on dose rate(PRF)rather than beam energy, field size. Conclusion : Presented result are under the limits(out put<3%, flatness<${\pm}3%$, symmetry<2%). The 3 accelerators are safe to use and to perform conformal radiotherapy treatments in small segments, small MU around 10MU. but Even if the result presented here under the limits, continuous adjustments and periodic QA should be done for use of small MU

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.24-38
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• 2019

Due to the dramatic spatial changes caused by industrialization, environmental problems such as air pollution and urban heat island phenomenon, etc. are occurring in cities. In this case, the wind corridor, which is a passage through which fresh and cool air generated in forests outside cities move to the downtown, can be used as a spatial planning method for improving urban environmental problems. Cold air is determined by the characteristics of the flow depending on the topography and land use of cities, and based on this, the medium- and long-term plan should be established. Therefore, this study analyzed the flow of cold air at night through the KLAM_21 model in Suwon-si, Gyeonggi-do, to prepare the basic data required to apply the wind corridors. As a result, it turned out that cold air of Suwon-si was mainly generated from Gwanggyo Mountain that is a large mountain area in the north, and flowed into the urbanization promotion area, and about three hours after sunset, cold air flowed into the downtown. By district, the depth, wind speed, and direction of the cold air layer were formed differently according to the characteristics of the topography and land use. In the areas where large forests were adjacent, the flow of cold air was active. There are three main wind corridors where cold air flows to the downtown of Suwon-si, all of which are formed around rivers. Especially, if the connection between rivers and the surrounding green areas is high, the effect of wind corridors is found to be significant. In order to utilize the wind corridors of Suwon-si, based on the results of this study, it is necessary to make climate maps through actual survey and complex analysis of cold air flow and establish mid-to-long-term plans for the conservation and expansion of major wind corridors.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.337-351
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• 2015

The articles, published in the Journal of Korean Forest Society from Volume 1 (1962) to Volume 102 (2013), were investigated for the research trend analysis about forest plants for special purposes, i.e., edible plants, medicinal plants, feed resources, landscape plants, fiber plants, industrial usage, bee plants, bioenergy/phytoremediation uses, dye materials, and rare/endangered/endemic plants. These research articles were classified again based on the contents of research into following categories - habitat environment, ecology, physiology, propagation, silviculture (including planting and tending), genetics and breeding, identification, pest and disease control, animal-related research, components analysis and extracts, vegetation survey, biotechnology, management, recreation and forest healing, and research review. Among the total 2,433 articles published, 611 (25.1%) were related to plants for special usage or purposes. The highest frequency (14.9%) in publications was found in the field of silviculture followed by physiology, propagation, identification, and genetics and breeding, respectively. On the bases of usage, edible plants showed higher frequency (26.5%) than others, followed by industrial purpose, bioenergy/phytoremediation usage, landscape plants, medicinal plants, and rare/endangered/endemic plants. Populus plant species was the most popular in research, showing 62 articles; and Castanea crenata 36; Pinus koraiensis 35; Robinia pseudoacacia 20; Ginko biloba 17, etc. Based on the survey and analysis, the following points are suggested: 1) improved evaluation of forest plants as non-wood resources, 2) expanding research topics on the basis of production, management, and utilization of non-wood forest resources, 3) management of database of forest plant information and encouragement needed to strengthen cooperative researches satisfying the needs of other industrial and scientific areas, and 4) encouraging to promote traditional knowledge based research on forest plants.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.1
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• pp.19-31
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• 2005

Purpose : To supply the information of EPID system and to analyze the possibility of substitution EPID for film dosimetry. Materials & Methods : With amorphous silicon(aSi) type EPID and liquid filled lonization chamber(LC) type EPID, the reproducibility according to focus detector distance(FDD) change and gantry rotation was analyzed, and also the possible range of image acquisition was analyzed with Alderson Rando phantom. The resolution and the contrast of aSi type EPID image were analyzed through Las Vegas phantom and water phantom. DMLC image was analyzed with X-Omat V film and EPID to see wether it could be applied to the qualify assurance(QA) of IMRT. Results : The reproducibility of FDD position was within 1mm, but the reproducibility of gantry rotation was ${\pm}2,\;{\pm}3mm$ respectively. The resolution and the contrast of EPID image were affected by dose rate, image acquisition time, image acquisition method and frame number. According to the possible range of image acquisition of EPID, it is verified that the EPID is easier to use than film. There is no difference between X-Omat V film and EPID images for the QA of IMRT. Conclusion : Through various evaluation, we could obtain lots of useful information about the EPID. Because the EPID has digital data, also we found that the EPID is more useful than film dosimerty for the periodical Qualify Assurance of IMRT. Especially when it is difficult to do point dose measurement with diode or ionization chamber, the EPID could be very useful substitute. And we found that the diode and ionization chamber are difficult to evaluate the sliding window images of IMRT, but the EPID was more useful to do it.