• KSBB Journal
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• v.10 no.5
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• pp.561-567
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• 1995

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxygen toxicity induced by paraquat was studied. In aerobic culture condition, yeasts lacking MnSOD (milochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared with wild type were observed under anaerobic condition. When exposed to paraquat, the growth of yeasts lacking CuZnSOD was severely affected by higher than 0.01mM of paraquat in culture medium. By the analysis of several cellular components ivolved in free radical generating and scavenging system, it was found that, under aerobic condition, the content of lipid peroxides in cell membrane as well as cellular activity of glutathion peroxidase of CuZnSOD-deficient mutants was increased in the presence of paraquat, although significant decrease of catalase activity was observed in those stratns. In MnSOD-deficient yeast, however, increment in cellular activity of glutathion peroxldase and catalase by paraquat was observed without any deterioration of membrane lipid. It implies that the lack of mitochondrial SOD could be compensated by both of glutathion peroxldase and catalase, but that only glutathion peroxidase might act for CuZnSOD in cytoplasm. In contrast, all of SOD-deficient mutants showed a significant decrease in catalase activity, but slight increase in the activities of glutathion peroxidase, when cultivated anaerobically in the medium containing paraquat. Nevertheless, any significant changes of lipid peroxides in cell membranes were not observed during anaerobic cultivation of SOD-deficient mutants. It suggests that a little amount of free radicals generated by paraquat under anaerobic condition could be sufficiently overcome by glutathion peroxidase but not by catalase.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.77-92
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• 2014

Recently, numerous documents including unstructured data and text have been created due to the rapid increase in the usage of social media and the Internet. Each document is usually provided with a specific category for the convenience of the users. In the past, the categorization was performed manually. However, in the case of manual categorization, not only can the accuracy of the categorization be not guaranteed but the categorization also requires a large amount of time and huge costs. Many studies have been conducted towards the automatic creation of categories to solve the limitations of manual categorization. Unfortunately, most of these methods cannot be applied to categorizing complex documents with multiple topics because the methods work by assuming that one document can be categorized into one category only. In order to overcome this limitation, some studies have attempted to categorize each document into multiple categories. However, they are also limited in that their learning process involves training using a multi-categorized document set. These methods therefore cannot be applied to multi-categorization of most documents unless multi-categorized training sets are provided. To overcome the limitation of the requirement of a multi-categorized training set by traditional multi-categorization algorithms, we propose a new methodology that can extend a category of a single-categorized document to multiple categorizes by analyzing relationships among categories, topics, and documents. First, we attempt to find the relationship between documents and topics by using the result of topic analysis for single-categorized documents. Second, we construct a correspondence table between topics and categories by investigating the relationship between them. Finally, we calculate the matching scores for each document to multiple categories. The results imply that a document can be classified into a certain category if and only if the matching score is higher than the predefined threshold. For example, we can classify a certain document into three categories that have larger matching scores than the predefined threshold. The main contribution of our study is that our methodology can improve the applicability of traditional multi-category classifiers by generating multi-categorized documents from single-categorized documents. Additionally, we propose a module for verifying the accuracy of the proposed methodology. For performance evaluation, we performed intensive experiments with news articles. News articles are clearly categorized based on the theme, whereas the use of vulgar language and slang is smaller than other usual text document. We collected news articles from July 2012 to June 2013. The articles exhibit large variations in terms of the number of types of categories. This is because readers have different levels of interest in each category. Additionally, the result is also attributed to the differences in the frequency of the events in each category. In order to minimize the distortion of the result from the number of articles in different categories, we extracted 3,000 articles equally from each of the eight categories. Therefore, the total number of articles used in our experiments was 24,000. The eight categories were "IT Science," "Economy," "Society," "Life and Culture," "World," "Sports," "Entertainment," and "Politics." By using the news articles that we collected, we calculated the document/category correspondence scores by utilizing topic/category and document/topics correspondence scores. The document/category correspondence score can be said to indicate the degree of correspondence of each document to a certain category. As a result, we could present two additional categories for each of the 23,089 documents. Precision, recall, and F-score were revealed to be 0.605, 0.629, and 0.617 respectively when only the top 1 predicted category was evaluated, whereas they were revealed to be 0.838, 0.290, and 0.431 when the top 1 - 3 predicted categories were considered. It was very interesting to find a large variation between the scores of the eight categories on precision, recall, and F-score.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.1
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• pp.108-119
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• 2015

Recently, the ways in which individual communities own and manage parks have been both discussed and realized in America and England. Some benefits of these asset transfers are that local governments can reduce the financial cost of management as well as improve the service of the parks. In addition, communities can develop these parks as unique assets. Ultimately, this is a new understanding of parks as community commons. This study examines the policy of park asset transfers to communities in England. These transfers, which involve reallocating land and building management and/or ownership from the public sector to a community group, are part of a policy agenda known as "Big Society", which aims to create a "small government" within a "big society". The agenda is pursued by both the English Conservative and Unionist Party governments. Eight case studies of community park asset transfers in England were examined in this study, under three categories-transfer process, partnership among stakeholders, and financial structure-and synthesized along three issues-financial contribution, level of public transparency, and closeness of the relationship between park and community. In some cases, new community groups were created specifically to receive park assets, while in other communities, existing groups became the park trustees. For most parks, community groups raise park maintenance funding through diverse methods; however, these groups are often not entirely financially independent from local government. Thus, many park trustees have already created, or are planning to create, other assets from which parks can benefit. Second, some efforts for public transparency include trusts that are registered as charities, of which their public nature is admitted officially. These trusts resolve important decisions through boards of trustees, in an effort to promote income-generating business while not excluding users. Ultimately, a close relationship between park and community empowers the community to participate in managing and maintaining the park; in turn, the park's capacities are improved. Current struggles include the many limits involved in communities accepting ownership and management of a park, and a lack of local government experience regarding public-private management and maintenance of a public asset. This study, however, details interesting policy implications for Korean community involvement as well as diverse financial methods to facilitate park management.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.1-11
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• 2012

This study focused on establishing a natural rainwater circulation system using rainwater meant for relatively large urban development projects such as a new town development. In particular, when the location selection techniques for individual elements of a natural rainwater circulation system are developed for the integrated rainwater management, changes in hydrological environment will be minimized and the natural water circulation would be restored to realize the low impact development (LID). In that case, not only the excess will be reduced but water space and green areas in a city would also increase to improve the urban sustainability. First of all, there were five elements selected for the location selection of a rainwater circulation system intended for the integrated rainwater management: rainwater collection, infiltration, filtration, retention and movement spaces. After generating these items, the location selection items and criteria were defined for each of the five elements. For a technique to apply the generated evaluation items and criteria, a grid cell analysis was conducted based m the suitability index theory, and thematic maps were overlapped through suitability assessment of each element and graded based on the suitability index. The priority areas were identified for each element. The developed technique was applied to a site where Gim-cheon Innovation City development is planned to review its feasibility and limitations. The combined score of the overlapped map for each element was separated into five levels: very low, low, moderate, high and very high. Finally, it was concluded that creating a rainwater circulation system conceptual map m the current land use plan based on the outcome of the application would be useful in building a water circulation system at the de1ailed space planning stage after environmental and ecological planning. Furthermore, we use the results of this study as a means for environment-friendly urban planning for sustainable urban development.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.115-134
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• 1997

We now live in the new era of globalization which implies the functional integration or increase of inter-dependency between internationally dispersed economic activities. As globalization impacts our various activities and daily lives, social sciences, including, geography, attempt to approach social phenomena from a global perspective. From this point of view. new regional geography, which has been articulated in recent social theory since the 1980s, also must adjust to these new world realities. This paper aims to search for a suitable methodology or approach to area study or regional geography in the era of globalization and to suggest the field of area study that Korean geographers should be concerned with in the future. This paper has reviewed the existing various methodologies of regional geography such as the ecological approach, the landscape approach. the areal differentiation approach, the system approach, the structuration theory, the spatial division of labour, and the world-system, which have deviced in the traditional and new regional geography. Peter Taylor's regional geography of world systems among them has an appropriate rationale of area study in the globalization era, because world-systems theory explains well globalization. However the regional geography of world-systems must be revised to become more suitable to the area-study approach in the globalization era. Firstly, the regional geography of world-systems explains that regions(historical regions) are made by general mechanisms of the capitalist world-economy that operate through social, economic, and political agents within regions such as individuals, households, social classes, economic enterprises, states, political movements, and many other organizations. But these mechanisms can also act through other regional agents of geographical location, natural conditions, and cultural characteristics. Therefore, the generating process of regions needs to be explained by locational, natural, and cultural elements in addition to social, economic, and political elements within regions. Secondly, Taylor's world-systems approach does not express composite characteristics of regions, because it focuses on the economic characteristics or position of regions within the world-economy. Regions incorporated into world-economy systems are not only changed economically, but also changed spatially, socially, culturally, and politically. Hence the world-systems approach must try to analyze these composite characteristics and their change of regions. Thirdly, The world-system approach proposed that the geography of regions within world-systems could be divided and analyzed as three regional types at the geographical scale such as international regions, state regions, and intra-state regions. However such a regionalization is usually not identified distinctly, because the geographical range of regions in world-systems shaped by economic boundaries of the general mechanisms of the world-economy is fluid and also occasionally overlaps with other political regions. Hence I propose that the world-systems approach should choose political boundaries of states and local autonomies in addition to economic boundaries for objective regionalization and systematic areal study. The revised regional geography of world-systems that I have suggested in this paper can be more effectively and properly applied to regional geography or area study in the globalization era. Globalization intensifies competition between states and also between local autonomies in the world. Therefore we must make efforts to study such areas or regions through the revised regional geography of world-system.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1186-1191
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• 2006

Removal efficiency of As(III) through oxidation and adsorption in column reactors was investigated at different ratios of manganese-coated sand(MCS) and iron-coated sand(ICS) : MCS-alone, ICS-alone and both of ICS and MCS. The breakthrough of arsenic immediately occurred from a column reactor with MCS-alone. However, most of the arsenic present in the effluent was identified as As(V) due to the oxidation of As(III) by MCS. While five-times delayed breakthrough of arsenic was observed from a column reactor with ICS-alone. At a complete breakthrough of arsenic, the removed As(III) was 36.1 mg with 1 kg ICS. To find an optimum ratio of ICS and MCS in the column packed with both ICS and MCS, the removal efficiency of As(III) was investigated at three different ratios of ICS/MCS with a fixed amount of ICS. The breakthrough time of arsenic was quite similar in the different ratios ICS/MCS. However, much slower breakthrough of arsenic was observed as the ratio of ICS/MCS decreased. As the ratio of ICS/MCS decreased the concentration of As(III) in the effluent decreased and then showed below 50 ppb at an equal amount of ICS and MCS, suggesting more efficient oxidation of As(III) by greater amount of MCS. When a complete breakthrough of arsenic occurred, the removed total arsenic with an equal amount of ICS and MCS was 68.5 mg with 1 kg of filter material.

• Journal of Korean Society of Transportation
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• v.23 no.1
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• pp.93-102
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• 2005

An Origin-Destination (O/D) is considered as one of the important information in route choices and trip assignments. A household interview survey is deemed to be the traditional and the most widely used method in making sample O/D and its conversion to the total O/D. Some researchers have studied to estimate dynamic O/D from the relationship between link volumes and trip assignment model. Nowadays, owing to the recent rapid spread of cellular phones. Location information of the cellular phone through the Base Station(BS) is considered as an alternative to O/D estimation. In this study, the methodology of generating BS-based O/D and the methodology of converting this O/D into an administrative district-based O/D are proposed. The information of GPS positions and cellular BS positions have acquired by establishing GPS equipment and cellular phone on taxies in Cheongju. Three weeks data are collected and used in estimating O/D by matching them on a digital map. Scatter diagram and sample correlation coefficients are used to investigate the similarity of the GPS-based O/D pattern among weeks, among days, and among times in day. The results show that there are few significant differences among weeks. But there is a difference in O/C pattern between weekday and weekend. Furthermore, there is a difference between morning peak and afternoon peak. Two methodologies are proposed to convert BS-based O/D into an administrative district-based O/D. The first one is to use the distribution pattern of GPS coordinates, the other is to use the coverage area of the BSs. To validate such converted O/D, GPS O/D is used as a true value. The statical analyses through scatter diagram, MAE and RMSE shows that there is few significant defference of pattern between the estimated BS-based O/D and GPS O/D. In the case of using only cellular information, the methodology using coverage area of the BSs is recommended for estimating O/D.

• The Korean Journal of Nuclear Medicine
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• v.39 no.3
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• pp.174-181
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• 2005

Purpose: Reduction of respiratory motion artifacts in PET images was studied using respiratory-gated PET (RGPET) with moving phantom. Especially a method of generating simulated helical CT images from 4D-CT datasets was developed and applied to a respiratory specific RGPET images for more accurate attenuation correction. Materials and Methods: Using a motion phantom with periodicity of 6 seconds and linear motion amplitude of 26 mm, PET/CT (Discovery ST: GEMS) scans with and without respiratory gating were obtained for one syringe and two vials with each volume of 3, 10, and 30 ml respectively. RPM (Real-Time Position Management, Varian) was used for tracking motion during PET/CT scanning. Ten datasets of RGPET and 4D-CT corresponding to every 10% phase intervals were acquired. from the positions, sizes, and uptake values of each subject on the resultant phase specific PET and CT datasets, the correlations between motion artifacts in PET and CT images and the size of motion relative to the size of subject were analyzed. Results: The center positions of three vials in RGPET and 4D-CT agree well with the actual position within the estimated error. However, volumes of subjects in non-gated PET images increase proportional to relative motion size and were overestimated as much as 250% when the motion amplitude was increased two times larger than the size of the subject. On the contrary, the corresponding maximal uptake value was reduced to about 50%. Conclusion: RGPET is demonstrated to remove respiratory motion artifacts in PET imaging, and moreover, more precise image fusion and more accurate attenuation correction is possible by combining with 4D-CT.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.62-66
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• 2015

Purpose Various database comparison methods(DCM) are used for analyzing functional neuro-imaging. It is possible to statistically evaluate decreased or increased metabolism of abnormal patient's brain by comparing with asymptomatic controls in DCM. And results of DCM are additionally used for easily explaining defect region. The aim of this study was to evaluate usefulness of statistical parametric mapping(SPM) and scenium. Materials and Methods Data of 15 patients($62.02{\pm}15.03year$) underwent $^{18}F-FDG$ brain PET/CT were collected and analyzed. Biograph TruePoint 40 with TrueV, (Siemens) was used as a PET/CT scanner. Scenium(version 4.0) in Syngo.via(version VA30A) and SPM99 were applied for statistical evaluation. Consistency between PET reading and result of DCM were evaluated by 5 nuclear medicine physicians through a questionnaire survey. SUV and SD changes were evaluated by changing iteration, gaussian filter and matrix size in scenium. And average required time for generating result of SPM99 and scenium was compared by 3 medical technologists. Results Consistency from the result of SPM99 and scenium showed 84% and 92.4% compare to PET reading. When iteration 4, FWHM 8 and matrix size 168, SUV and SD were decreased by 0.59%, 8.73%, 4.69%, 20.38% and 0.88%, 8.25% respectively compare to routine parameter(iteration 8, FWHM 2 and matrix size 336) of scenium. Average required time of SPM99 and Scenium took 282 seconds and 116 seconds to generate result. Conclusion Results of SPM99 and Scenium showed high consistency compare to PET reading. Various parameters can be controled by user when using SPM. However, normal database needs to be acquired. And it takes significant amount of time and effort for the first set up. On the other hand, Scenium provides normal database even though modifiable parameters are limited. Therefore, more informations could be provided for brain PET/CT if properly understanding and selecting each DCM.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.213-222
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• 1998

Electro-Optical Camera(EOC) is the main payload of the KOrea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including a Digital Terrain Elevation Map(DTEM). This instalment which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510~730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response, the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the users of EOC data. The modulation transfer function of EOC was measured as greater than 16 % at Nyquist frequency over the entire field of view, which exceeds its requirement of larger than 10 %. The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.