• Journal of agricultural medicine and community health
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• v.43 no.4
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• pp.258-269
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• 2018

Objectives: There was an outbreak of foodborne and waterborne disease among high school students at Okcheon in June, 2018. First attack occurred June $5^{th}$ but seven days later it was notified. The purpose of this investigation was to evaluate the pathogen of outbreak and cause of delayed notification. Methods: First, we did a questionnaire survey for 61 cases and 122 controls to find what symptoms they had and whether they ate foods or drank water from June $2^{nd}$ to June $12^{th}$. Second, we investigated the environment of cafeteria and drinking water. Third, we examined specimen of cases and environment to identify bacteria or virus. Results: Attack rate of this outbreak was 7.8%. Drinking water was strongly suspected as a source of infection in questionnaire survey but we could not find the exact time of exposure. Norovirus was identified in specimen of cases (2 students), drinking water (at main building and dormitory) and cafeteria (knife, dishtowel, hand of chef) Conclusions: We decided norovirus as the pathogen of this outbreak based on the clinical features of cases with diarrhea vomiting, abdominal pain and recovery within 2 or 3 days after onset, outbreak due to drinking water and microbiologic examination, And the cause of delayed notification might be the non-existence of the nurse teacher at that time and the lack of understanding of teachers on immediate notification under the outbreak. To prevent the delayed notification, notification system about outbreak of foodborne and waterborne disease in school is needed to be improved.

• Korea Science and Art Forum
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• v.25
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• pp.103-118
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• 2016

Due to the rapid development of ICT, corporate business models quickly changed and because of the radical growth of IT technology, sequential or gradual survival has become difficult. Internet-based new businesses such as IT service companies are seeking for new convergence business models that have not existed before to create business models that are more competitive, but the economic efficiency of business models that were successful in the past is wearing off. Yet, as reaching the critical point where the platform value becomes extremely high for platforms via the Internet is happening at a much higher speed than before, platform-ization has become a very important condition for rapid business expansion for all kinds of businesses. This study analyzes the necessity of establishing platform business models in IT service planning and identifies their characteristics through case analyses of platform business models. The results derived features First, there is a need to ensure sufficient buyers and sellers, and second, platform business model should provide customers with distinctive value of the only platforms are generating. third, the common interests between platform-driven company and a partner, participants Should be existing. Fourthly, by expanding base of participants and upgrades, expansion of adjacent areas we must have a continuous scalability and evolution must be sustainable. While it is expected that the identified characteristics will cause tremendous impacts to the establishment of platform business models and to the graphing of service planning, we also look forward to this study serving as the starting point for the establishment of theories of profit models for platform businesses, which were not mentioned in the study, so that planners responsible for platform-based IT service planning will spend less time and draw bigger schemes in building planning drafts.

• 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 Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.68-81
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• 2014

This study was conducted to identify the spacialty, to illuminate the existence and values of Myeongwoldae(明月臺) and Forest Myeongwol, and to suggest the sustainable usage, preservation and management plans with the purpose of ecological and cultural landscaping characteristic and value identification. The result of the study is as follows. Castle Myeongwol and Port Myeongwol shows the status of Hallim-eup Myeongwol District which is the administrative center of western Jeju as well as is the fortress. Building Wolgyejeongsa and School Woohakdang, the head temple of education and culture, located in Myeongwol District represents the spaciality of Myeonwol-ri which was the center of education. Stand Myeongwol is one of the most representative Confucian cultural landscapes in Jeju Island and the field of communion with nature where scholars enjoy poetries, nature, changgi(Korean chess), and go in the Joseon Dynasty period. It was found that the current relics of Myeongwoldae was recovered through the maintenance project conducted by Youth Group Myeongwol composed with Hongjong-si(洪鍾時) as the center during the Japanese colonial era in 1931. It seems that the stonework of Myeongwoldae composed of three levels in the order of square, octagon, and circle based on the heaven-man unity theory of Confucianism and the octagon in the middle is the messenger of Cheonwonjibang(天圓地方), in other words, between the square-shaped earth and the circle-shaped sky. It is assumed that both Grand Bridge Myeongwol and Bridge Myeongwol were constructed as arched bridges in early days. Bridge Myeongwol is the only arched bridge remaining in Jeju Island now, which has the modern cultural heritage value. In Forest Myeongwol, 97 taxa of plants were confirmed and in accordance with 'Taxonomic Group and Class Criteria of Floristic Specific Plants', eight taxa were found; Arachniodes aristata of FD IV and Ilex cornuta, Piper kadsura, Litsea japonica, Melia azedarach, Xylosma congestum, Richosanthes kirilowii var. japonica, Dichondra repens, Viburnum odoratissimum var. awabuki of FD III. Otherwise, 14 taxa of naturalized plants including Apium leptophylihum which is imported to Jeju Island only were confirmed. In Forest Myeongwol, 77 trees including 41 Celtis sinensis, 30 Aphananthe aspera, two Wylosma congestum, a Pinus densiflora, a Camellia japonica, a Melia azedarach, and an Ilex cornuta form a colony. Based on the researched data, the preservation and plans of Myeongwoldae and Forest Myeongwol is suggested as follows. Myeongwoldae, Bridge Myeongwol, and Forest Myeongwol should be managed as one integrated division. Bridge Myeongwol, an arched bridge which is hard to be found in Jeju Island is a high-standard stonework requiring long-term preservation plans. Otherwise, Grand Bridge Myeongwol that is exposed to accident risks because of deterioration and needs safety diagnosis requires measures according to the result of precise safety diagnosis. It is desirable to restore it to a two-sluice arched bridge as its initial shape and to preserve and use it as a representative local landmark with Stand Myeongwol. In addition, considering the topophsis based on the analysis result, the current name of Jeju Special Self-Governing Province Monument No. 19 'Myoengwol Hackberry Colony' should change to 'Myeongwol Hackberry-Muku Tree Colony'. In addition, the serial number system which is composed without distinction of hackberry and muku tree should be improved and the regular monitoring of big and old trees, specific plants, and naturalized species is required.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.157-175
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• 2013

Since Korean government announced 'Smartwork promotion strategy' in 2010, Korean firms and government organizations have started to adopt smartwork. However, the smartwork has been implemented only in a few of large enterprises and government organizations rather than SMEs (small and medium enterprises). In USA, both Yahoo! and Best Buy have stopped their flexible work because of its reported low productivity and job loafing problems. In addition, according to the literature on smartwork, we could draw obstacles of smartwork adoption and categorize them into the three types: institutional, organizational, and technological. The first category of smartwork adoption obstacles, institutional, include the difficulties of smartwork performance evaluation metrics, the lack of readiness of organizational processes, limitation of smartwork types and models, lack of employee participation in smartwork adoption procedure, high cost of building smartwork system, and insufficiency of government support. The second category, organizational, includes limitation of the organization hierarchy, wrong perception of employees and employers, a difficulty in close collaboration, low productivity with remote coworkers, insufficient understanding on remote working, and lack of training about smartwork. The third category, technological, obstacles include security concern of mobile work, lack of specialized solution, and lack of adoption and operation know-how. To overcome the current problems of smartwork in reality and the reported obstacles in literature, we suggest a novel smartwork service model based on NFC(Near Field Communication). This paper suggests NFC-based Smartwork Service Model composed of NFC-based Smartworker networking service and NFC-based Smartwork space management service. NFC-based smartworker networking service is comprised of NFC-based communication/SNS service and NFC-based recruiting/job seeking service. NFC-based communication/SNS Service Model supplements the key shortcomings that existing smartwork service model has. By connecting to existing legacy system of a company through NFC tags and systems, the low productivity and the difficulty of collaboration and attendance management can be overcome since managers can get work processing information, work time information and work space information of employees and employees can do real-time communication with coworkers and get location information of coworkers. Shortly, this service model has features such as affordable system cost, provision of location-based information, and possibility of knowledge accumulation. NFC-based recruiting/job-seeking service provides new value by linking NFC tag service and sharing economy sites. This service model has features such as easiness of service attachment and removal, efficient space-based work provision, easy search of location-based recruiting/job-seeking information, and system flexibility. This service model combines advantages of sharing economy sites with the advantages of NFC. By cooperation with sharing economy sites, the model can provide recruiters with human resource who finds not only long-term works but also short-term works. Additionally, SMEs (Small Medium-sized Enterprises) can easily find job seeker by attaching NFC tags to any spaces at which human resource with qualification may be located. In short, this service model helps efficient human resource distribution by providing location of job hunters and job applicants. NFC-based smartwork space management service can promote smartwork by linking NFC tags attached to the work space and existing smartwork system. This service has features such as low cost, provision of indoor and outdoor location information, and customized service. In particular, this model can help small company adopt smartwork system because it is light-weight system and cost-effective compared to existing smartwork system. This paper proposes the scenarios of the service models, the roles and incentives of the participants, and the comparative analysis. The superiority of NFC-based smartwork service model is shown by comparing and analyzing the new service models and the existing service models. The service model can expand scope of enterprises and organizations that adopt smartwork and expand the scope of employees that take advantages of smartwork.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.75-84
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• 2008

The purpose of this research is to find the visual characteristics and geographic structure in a landscape of mountains in Yangsan City. In order to carry out this study, 40 view points of 6 mountains in Yangsan City were selected to experience the mountainscape. The results are as follows. The mountainscape of Yangsan City was confirmed from the view point to the object of view as ranging in middle distance reverse, the angle of elevation 11${\sim}13^{\circ}$ which give the impression of confronted to the mountain, and the horizontal angle 50${\sim}90^{\circ}$ which gives the impression of vastness. This shows that mountainscapes are perceived impressively when seeing the mountain with the meaning to feel the texture of the mountain as a confrontational relationship rather than a pictorial relationship. The geographic structure of the view point which occurs in scenes of impressive experience is classified into eight types and its characteristics are investigated. The first type is corridor, and it emerges in a long narrow linear structure made from the surrounding environment with buildings or street trees. The second is tunnel in which a vision and light hidden while passing underneath a bridge, high-level road, or inside a tunnel can be seen. Third, the maze is formed by the mountain shape. The hill spur emerges when the direction of traffic changes after turning the coner of a building or mountain edge. The hill ground emerges at the top of a hill slope. Next, parallel emerges when the observer and the mountain are in the same direction of process. Confrontation occurs when confronting an isolated mountain. Finally, the view point emerges when passing through major points such as a bridge or square and the boundary of a village or city. This research arranged visual conditions that create impressive mountainscapes. Geographic characteristics in terms of Types that make possible to experience mountainscapes were described. The results of this research will be basic data collected for the management and preservation of mountainscapes and for landscape effect evaluation. Furthermore, this research suggests theoretical evidence to preserve and manage geographic structures that create view experiences as well as to preserve the landscape in terms of view points.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.11-19
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• 2012

Air-borne pollen, biogenically created aerosol particle, influences Earth's radiative balance, visibility impairment, and human health. The importance of pollens has resulted in numerous experimental studies aimed at characterizing their dispersion and transport, as well as health effects. There is, however, limited scientific information concerning the optical properties of airborne pollen particles contributing to total ambient aerosols. In this study, for the first time, optical characteristics of pollen such as aerosol backscattering coefficient, aerosol extinction coefficient, and depolarization ratio at 532 nm and their effect to the atmospheric aerosol were studied by lidar remotes sensing technique. Dual-Lidar observations were carried out at the Gwangju Institute of Science & Technology (GIST) located in Gwagnju, Korea ($35.15^{\circ}E$, $126.53^{\circ}N$) for a spring pollen event from 5 to 7 May 2009. The pollen concentration was measured at the rooftop of Gwangju Bohoon hospital where the building is located 1.0 km apart from lidar site by using Burkard trap sampler. During intensive observation period, high pollen concentration was detected as 1360, 2696, and $1952m^{-3}$ in 5, 6, and 7 May, and increased lidar return signal below 1.5km altitude. Pollen optical depth retrieved from depolarization ratio was 0.036, 0.021, and 0.019 in 5, 6, and 7 May, respectively. Pollen particles mainly detected in daytime resulting increased aerosol optical depth and decrease of Angstrom exponent.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.388-395
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• 2016

This paper explores the photocatalytic sensitivity of cement mortar incorporated with recycled $TiO_2$ from waste water sludge. Basically, $TiO_2$ cluster sank down slowly to the bottom of cement mortar specimen before setting and hardening process. This leads the mismatch of $TiO_2$ concentration on the top and the bottom faces of a specimen. This poorly dispersed $TiO_2$-cement mortar naturally exhibits poor NOx removal efficiency especially on the top of cementitious structure. In architectural engineering application such as building or housing structures, one can simply filp over from the bottom so that more $TiO_2$ concentrated surface can be placed outward into the air. However, in highway pavement case, this could not be applicable due to in-situ installation of concrete pavement. Hence, the dispersion of $TiO_2$ cluster inside the cementitous material is getting important issue onto road construction application. To elaborate this issue, according to our results, silica fume, high-ranged water reducer, viscosity agent, blast furnace slag were not enhanced much of dispersion characteristics of $TiO_2$ cluster. The combination of foaming agent and accelerator of hardening with viscosity agent and small grain size of fine aggregate may help the dispersion of $TiO_2$ inside cementitious materials. Even though the enhanced dispersion were applied to the specimen, NOx removal efficiency doest not change much for the top surface of the specimen. This concurrently affected by the presence of tiny air voids and the dispersion of $TiO_2$ in that these voids could easily adsorbed NOx gas with the aid of large surface area.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.62-74
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• 2015

This study was carried out to provide examples of planting methods for the construction of street green spaces with abundant greenery by analyzing road type, surrounding land use and planting structures in street green spaces on Port Island, Kobe, Japan. Port Island_(total area: 826ha) is a marine cultural city located in Japan's first artificial island with facilities of urban function and port facilities. The study site was designated at 11 plots of $55{\sim}285m^2$ on Port Island, and topography structure styles were divided into four types with mounding style, slope style, slope and flat style, flat style according to the adjacent roads width. The area adjacent to the middle roads with high levels of noise and pollution set up the mounding style, slope style, slope and flat style of multi-layer structures using topographic properties. The area adjacent to small roads focused on a green strip with shrubs on a flat style. Surrounding land-uses include a public institution, housing complex, and a commercial building. The planting concept was a buffer and landspace function in case of the middle road_(lane 4) while the small road_(lane 2) was a landspace function. Planting species were diverse with Liquidambe formosana, Cinnamomum camphora, Sapium sebiferum, Cedrela sinensis, Laeocarpus sylvestris var. ellipticus, Ginkgo biloba, Prunus serrulata var. spontanea, Zelkova serrata, Quercus glauca, Juniperus chinensis, Magnolia kobus, Rhododendron spp., Camellia japonica, Abelia mosanensis, etc. Planting density was 0.02~0.08(0.04) individual/$m^2$ at the canopy layer, 0.02~0.08(0.04) individual/$m^2$ at the understory layer. Ratio of green coverage was 40.0~173.7(93.0)% at the canopy layer, 2.1~79.8(34.9)% at the understory layer and 17.9~64.2(32.9)% at the shrub layer. $Gr{\ddot{u}}volumenzahl$ was $1.43{\sim}6.67(4.13)m^3/m^2$ at the canopy layer, $0.02{\sim}2.01(0.85)m^3/m^2$ at the understory layer and $0.14{\sim}0.58(0.26)m^3/m^2$ at the shrub layer. The ratio of green coverage of street green space on Port Island was higher than that of Seoul, and particularly, the ratio of green coverage and $gr{\ddot{u}}volumenzahl$ at the shrub layer differed, compared to the main street green space in Korea. The result of this study may be applicable to other coastal reclaimed cities in terms of setting methods for street greenery considering the topography structure, planting structure and planting function.

• Journal of Intelligence and Information Systems
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• v.21 no.3
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• pp.19-36
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• 2015

Social media is an emerging issue in content services and in current business environment. YouTube is the most representative social media service in the world. YouTube is different from other conventional content services in its open user participation and contents creation methods. To promote a content in YouTube, it is important to understand the diffusion phenomena of contents and the network structural characteristics. Most previous studies analyzed impact factors of contents diffusion from the view point of general behavioral factors. Currently some researchers use network structure factors. However, these two approaches have been used separately. However this study tries to analyze the general impact factors on the view count and content based network structures all together. In addition, when building a content based network, this study forms the network structure by analyzing user comments on 22,370 contents of YouTube not based on the individual user based network. From this study, we re-proved statistically the causal relations between view count and not only general factors but also network factors. Moreover by analyzing this integrated research model, we found that these factors affect the view count of YouTube according to the following order; Uploader Followers, Video Age, Betweenness Centrality, Comments, Closeness Centrality, Clustering Coefficient and Rating. However Degree Centrality and Eigenvector Centrality affect the view count negatively. From this research some strategic points for the utilizing of contents diffusion are as followings. First, it is needed to manage general factors such as the number of uploader followers or subscribers, the video age, the number of comments, average rating points, and etc. The impact of average rating points is not so much important as we thought before. However, it is needed to increase the number of uploader followers strategically and sustain the contents in the service as long as possible. Second, we need to pay attention to the impacts of betweenness centrality and closeness centrality among other network factors. Users seems to search the related subject or similar contents after watching a content. It is needed to shorten the distance between other popular contents in the service. Namely, this study showed that it is beneficial for increasing view counts by decreasing the number of search attempts and increasing similarity with many other contents. This is consistent with the result of the clustering coefficient impact analysis. Third, it is important to notice the negative impact of degree centrality and eigenvector centrality on the view count. If the number of connections with other contents is too much increased it means there are many similar contents and eventually it might distribute the view counts. Moreover, too high eigenvector centrality means that there are connections with popular contents around the content, and it might lose the view count because of the impact of the popular contents. It would be better to avoid connections with too powerful popular contents. From this study we analyzed the phenomenon and verified diffusion factors of Youtube contents by using an integrated model consisting of general factors and network structure factors. From the viewpoints of social contribution, this study might provide useful information to music or movie industry or other contents vendors for their effective contents services. This research provides basic schemes that can be applied strategically in online contents marketing. One of the limitations of this study is that this study formed a contents based network for the network structure analysis. It might be an indirect method to see the content network structure. We can use more various methods to establish direct content network. Further researches include more detailed researches like an analysis according to the types of contents or domains or characteristics of the contents or users, and etc.