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Empirical Forecast of Corotating Interacting Regions and Geomagnetic Storms Based on Coronal Hole Information (코로나 홀을 이용한 CIR과 지자기 폭풍의 경험적 예보 연구)

  • Lee, Ji-Hye;Moon, Yong-Jae;Choi, Yun-Hee;Yoo, Kye-Hwa
    • Journal of Astronomy and Space Sciences
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    • v.26 no.3
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    • pp.305-316
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    • 2009
  • In this study, we suggest an empirical forecast of CIR (Corotating Interaction Regions) and geomagnetic storm based on the information of coronal holes (CH). For this we used CH data obtained from He I $10830{\AA}$ maps at National Solar Observatory-Kitt Peak from January 1996 to November 2003 and the CIR and storm data that Choi et al. (2009) identified. Considering the relationship among coronal holes, CIRs, and geomagnetic storms (Choi et al. 2009), we propose the criteria for geoeffective coronal holes; the center of CH is located between $N40^{\circ}$ and $S40^{\circ}$ and between $E40^{\circ}$ and $W20^{\circ}$, and its area in percentage of solar hemispheric area is larger than the following areas: (1) case 1: 0.36%, (2) case 2: 0.66%, (3) case 3: 0.36% for 1996-2000, and 0.66% for 2001-2003. Then we present contingency tables between prediction and observation for three cases and their dependence on solar cycle phase. From the contingency tables, we determined several statistical parameters for forecast evaluation such as PODy (the probability of detection yes), FAR (the false alarm ratio), Bias (the ratio of "yes" predictions to "yes" observations) and CSI (critical success index). Considering the importance of PODy and CSI, we found that the best criterion is case 3; CH-CIR: PODy=0.77, FAR=0.66, Bias=2.28, CSI=0.30. CH-storm: PODy=0.81, FAR=0.84, Bias=5.00, CSI=0.16. It is also found that the parameters after the solar maximum are much better than those before the solar maximum. Our results show that the forecasting of CIR based on coronal hole information is meaningful but the forecast of goemagnetic storm is challenging.

A Study on the Landscape Characteristics of 16 Sceneries of Hahoe Village, Represented in "Hahoe 16 Sceneries" and "Picture Describing Hahwae Village" ("화회십육경(河回十六景)"과 "하외낙강상하일대도(河隈洛江上下一帶圖)"를 통해 본 하회16경의 경관상)

  • Rho, Jae-Hyun;Lee, Hyun-Woo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.1
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    • pp.48-58
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    • 2013
  • The results of this research to study forms, structure, changes, symbolic meanings of 16 Hahoe sceneries through analyses of "Hahwaesipyukgyeong" and "Hahwaenakgangsanghaildaedo" are as belows. The coherence of headword is not discovered in 16 Hahoe sceneries, but based on various variables and sense dependence, endemicity with original natural scenes, human's life and phenomena of riverside village are spread in 3km viewing areas within 200m from Gyeonamjeongsa(謙巖精舍) and Okyeonjeongsa(玉淵精舍). As the viewing points of Gyeonam and Okyeonjeongsa are symmetrically facing and separately independent, while viewing angles do not intersect at Wonjijeongsa (遠志精舍) and Binyeonjeongsa(賓淵精舍) because of Buyongdae(芙蓉臺), and crating each independent viewing area, we can see 16 Hahoe sceneries are perfect views by supplementing Gyeonam and Okyeon Jeongsa, as well as points of views from Wonji and Binyeonjeongsa. Meanwhile, as the view point of 16 Hahoe sceneries, Gyeomam, Okyeon, Binyeon, and Wonji Jeongsa are clearly described, and 12 natural sceneries, which are Hwasan(花山), Ipam(立巖), Maam(馬巖), Jando(棧道), Bangi(盤磯), Hoengju(橫舟), and Honggyo(虹橋), among landscape elements of 16 Hahoe sceneries that can be expressed on canvas in the Haoedo are realistically described, there is high possibility that Haoedo is the 'Mental Stroll about Nature(臥遊) of 16 Hahoe sceneries. The belted forest surrounding the village in the painting is assumed to be an erosion control forest, and considering row-expressed trees, the south belted forest may be a different broad-leaved forest from current Mansongjeong(萬松亭) pine forest. In 16 Hahoe sceneries, there is Neo-confucianism tendency, which connects the nature and human life, and moreover prioritize human life than the nature. Especially as seen in the 'Choljae(拙齋)', the pen name of 16 Hahoe sceneries' author park, the 16 Hahoe scenery poet suggests 'Beauty of Jolbak(拙撲美)' based on the simple life that upright classical scholars pursued as the basic emotion. The thinking system shown in the poet is interpreted as Neo-confucianism category including one's sense and emotion depended on natural features or phenomena. Ultimately, 16 Hahoe sceneries are landscape that reflects moral world views of Confucianism scholars who wanted to express ideal thoughts based on natural features and phenomena in reality at Jeongsa in Buyongdae and Hahoe Village.

Analyzing the Effect of Online media on Overseas Travels: A Case study of Asian 5 countries (해외 출국에 영향을 미치는 온라인 미디어 효과 분석: 아시아 5개국을 중심으로)

  • Lee, Hea In;Moon, Hyun Sil;Kim, Jae Kyeong
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.53-74
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    • 2018
  • Since South Korea has an economic structure that has a characteristic which market-dependent on overseas, the tourism industry is considered as a very important industry for the national economy, such as improving the country's balance of payments or providing income and employment increases. Accordingly, the necessity of more accurate forecasting on the demand in the tourism industry has been raised to promote its industry. In the related research, economic variables such as exchange rate and income have been used as variables influencing tourism demand. As information technology has been widely used, some researchers have also analyzed the effect of media on tourism demand. It has shown that the media has a considerable influence on traveler's decision making, such as choosing an outbound destination. Furthermore, with the recent availability of online information searches to obtain the latest information and two-way communication in social media, it is possible to obtain up-to-date information on travel more quickly than before. The information in online media such as blogs can naturally create the Word-of-Mouth effect by sharing useful information, which is called eWOM. Like all other service industries, the tourism industry is characterized by difficulty in evaluating its values before it is experienced directly. And furthermore, most of the travelers tend to search for more information in advance from various sources to reduce the perceived risk to the destination, so they can also be influenced by online media such as online news. In this study, we suggested that the number of online media posting, which causes the effects of Word-of-Mouth, may have an effect on the number of outbound travelers. We divided online media into public media and private media according to their characteristics and selected online news as public media and blog as private media, one of the most popular social media in tourist information. Based on the previous studies about the eWOM effects on online news and blog, we analyzed a relationship between the volume of eWOM and the outbound tourism demand through the panel model. To this end, we collected data on the number of national outbound travelers from 2007 to 2015 provided by the Korea Tourism Organization. According to statistics, the highest number of outbound tourism demand in Korea are China, Japan, Thailand, Hong Kong and the Philippines, which are selected as a dependent variable in this study. In order to measure the volume of eWOM, we collected online news and blog postings for the same period as the number of outbound travelers in Naver, which is the largest portal site in South Korea. In this study, a panel model was established to analyze the effect of online media on the demand of Korean outbound travelers and to identify that there was a significant difference in the influence of online media by each time and countries. The results of this study can be summarized as follows. First, the impact of the online news and blog eWOM on the number of outbound travelers was significant. We found that the number of online news and blog posting have an influence on the number of outbound travelers, especially the experimental result suggests that both the month that includes the departure date and the three months before the departure were found to have an effect. It is shown that online news and blog are online media that have a significant influence on outbound tourism demand. Next, we found that the increased volume of eWOM in online news has a negative effect on departure, while the increase in a blog has a positive effect. The result with the country-specific models would be the same. This paper shows that online media can be used as a new variable in tourism demand by examining the influence of the eWOM effect of the online media. Also, we found that both social media and news media have an important role in predicting and managing the Korean tourism demand and that the influence of those two media appears different depending on the country.

Counter-terrorism Safety Measures in Public Facilities (다중이용시설의 대테러 안전대책)

  • Kim, Du-Hyun;Ahn, Kwang-Ho
    • Korean Security Journal
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    • no.22
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    • pp.37-64
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    • 2010
  • Since the September 11, 2001, the motives and objectives of terrorism that have been targeted at hard targets such as key national facilities have now shifted towards soft targets such as subways, department stores, and tourist hotels; the attacks on these soft targets are steadily increasing. Simultaneous, unconventional, and indiscriminate terrorist attacks on civilians has also increased. In November, 2010, nearly forty states of the G20 and B20 (Business 20) will join in international summits to be hosted in Seoul. This coming July, an additional 350 troops will be deployed to Afghanistan for the sustainment of public security. Such events are sensitive topics, and there is the possibility of terrorist movement. Korea has successfully hosted various international events such as the APEC and ASEM Summits, and the 2002 Korea-Japan World Cup. The experiences from these events must be applied to ensure the safety of public facilities against the dangers of terrorism. First, counter-terrorism center must be established for the long-term, above the General Officer level to ensure the safety and efficiency of multilateral, international summits, as well as promoting policies and legislation aimed at preventing terrorism. Second, a terrorist threat management system must be secured and safety measures must be emphasized. Third, a fundamental structure must be established for the prevention of terrorism on public facilities, as well as legal and government action against the new threat of IED. Fourth, the police and fire fighting networks' must have a firm rapid response posture on the scene of an attack. Fifth, the state of mentality on the recognition of terrorist threats must be changed and restructured by promoting to and educating the population. Sixth, prevention measures must be established via research and academia. Seventh, for the guarantee of security in public facilities, safety management should employ cutting edge technology such as the 3D SICS and further develop and apply such technology. All methods and resources must be fully utilized for the establishment and strengthening terrorism prevention measures.

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The Comparison of Existing Synthetic Unit Hydrograph Method in Korea (국내 기존 합성단위도 방법의 비교)

  • Jeong, Seong-Won;Mun, Jang-Won
    • Journal of Korea Water Resources Association
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    • v.34 no.6
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    • pp.659-672
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    • 2001
  • Generally, design flood for a hydraulic structure is estimated using statistical analysis of runoff data. However, due to the lack of runoff data, it is difficult that the statistical method is applied for estimation of design flood. In this case, the synthetic unit hydrograph method is used generally and the models such as NYMO method, Snyder method, SCS method, and HYMO method have been widely used in Korea. In this study, these methods and KICT method, which is developed in year 2000, are compared and analyzed in 10 study areas. Firstly, peak flow and peak time of representative unit hydrograph and synthetic unit hydrograph in study area are compared, and secondly, the shape of unit hydrograph is compared using a root mean square error(RMSE). In Nakayasu method developed in Japan, synthetic unit hydrograph is very different from peak flow, peak time, and the shape of representative unit hydrograph, and KICT method(2000) is superior to others. Also, KICT method(2000) is superior to others in the aspects of using hydrologic and topographical data. Therefore, Nakayasu method is not a proper in hydrological practice. Moreover, it is considered that KICT model is a better method for the estimation of design flood. However, if other model, i.e. SCS method, Nakayasu method, and HYMO method, is used, parameters or regression equations must be adjusted by analysis of real data in Korea.

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Distribution of Benthic Macrofauna in subtidal area and on sand flat of Sindu-ri coast, Korea (신두리 해안의 조하대와 모래 갯벌에 서식하는 대형저서동물의 분포)

  • Koo, Bon Joo;Shin, Sang Ho;Woo, Han Jun
    • Journal of Wetlands Research
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    • v.7 no.2
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    • pp.69-88
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    • 2005
  • Distribution of benthic macrofauna was surveyed in the subtidal area and on the sand flat of Sindu-ri coast during July 2002. A total of 134 species, 3,511 individuals and 388g biomass of macrobenthos were sampled inclusively from the study sites. 109 species with a mean density of $1,298ind./m^2$ and biomass of $69.4g/m^2$ were collected from 10 stations established in the subtidal area. Polychaetes were represented as a dominant faunal group of the subtidal area in both species richness and density with values of 54 species and $813ind./m^2$. Cluster analysis based on the faunal composition showed that the subtidal area could be divided into four stational groups according to sedimentary characteristics: Cirrophorus armatus - Lumbrineris longifolia association on the mud sediment with pebbles near aqua-farms; Aonides oxycephala association on the rocky bed; Scoloplos armiger - Grandifoxus cuspis association on the sand-dominated sediment along the lowest low water; a association with higher evenness on the sand-dominated sediment in the depth. Although having characteristics of high value in species richness, density and species diversity, the macrobenthic association around the farming area was dominated by the opportunistic species such as Lumbrineris longifolia and Tharyx sp. Natural community represented by S. armiger and G. cuspis was developed in most sand-dominated areas. 50 species were sampled with a mean density of $2,443ind./m^2$ and biomass of $381.3g/m^2$ from eight+ stations along two transects on Sindu-ri sand flat. Mollusks were represented as a dominant faunal group of the sand flat in species richness, density and biomass with values of 20 species, $1,345ind./m^2$ and $350.4g/m^2$, respectively. Umbonium thomasi, Veneridae sp., Mandibulophoxus mai, Armandia lanceolata, Eohaustorius spinigerus, Urothoe convexa were dominant species and these species accounted for over 83% of total individuals. There were three distinct zones of macrobenthos on Sindu-ri sand flat according to the extent of exposure time. The upper zone was dominated by Scopimera globosa, the middle zone was characterized by M. mai, and the lower zone was dominated by E. spinigerus. Sindu-ri coastal area was considered as a healthy habitat for macrobenthos, except for around the farming area. It was considered that Sindu-ri coastal area including the sand flat connected to the sand dune of natural monument was a valuable habitat as a protected site in having no pollution source and no artificial structure.

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Study on the Community Structure of Benthic Macro-Invertebrates in Jangsu-cheon, an Urban Restoration Stream of Incheon City (인천시 도시복원하천 장수천의 저서성대형무척추동물의 군집구조에 관한 연구)

  • Song, Yeong-Ju;Ju, Yong-Don;Park, Bo-Sun;Kim, Jong-Myung;Kwon, Eun-Ho;Chae, Do-Young;Lee, Hee-Jo;Bae, Yang-Seop
    • Journal of Wetlands Research
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    • v.18 no.1
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    • pp.32-38
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    • 2016
  • The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

The Improvement of Real-time Updating Methods of the National Base Map Using Building Layout Drawing (건물배치도를 이용한 국가기본도 수시수정 방법 개선)

  • Shin, Chang Soo;Park, Moon Jae;Choi, Yun Soo;Baek, kyu Yeong;Kim, Jaemyeong
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.1
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    • pp.139-151
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    • 2018
  • The National Base Map construction consists of the regular correction work of dividing the whole country into two regions and carrying out the modification Plotting by aerial photographs every two years as well as the real time updating work of correcting the major change feature within two weeks by the field survey and the As-Built Drawing. In the case of the Building Layout Drawing of Korea Real estate Administration intelligence System(KRAS) used for real time updating work of the National base map, the coordinate transformation error is included in the positional error when applied to the National Base Map based on the World Geodetic Reference System as the coordinate system based on the Regional Geodetic Reference System. In addition, National Base Map is registered based on the outline(eaves line) of the building in the Digital Topographic Map, and the Cadastral and Architecture are registered based on the building center line. Therefore, the Building Object management standard is inconsistent. In order to investigate the improvement method, the network RTK survey was conducted directly on a location of the Building Layout Drawing of Korea Real estate Administration intelligence System(KRAS) and the problems were analyzed by comparing with the plane plotting position reference in National Base Map. In the case of the general structure with the difference on the Building center line and the eaves line, beside the location information was different also the difference in the ratio of the building object was different between Building center line and the eave. In conclusion, it is necessary to provide the Base data of the double layer of the Building center line and the outline of the building(eaves line) in order to utilize the Building Layout Drawing of Korea Real estate Administration intelligence System(KRAS). In addition, it is necessary to study an organic map update process that can acquire the up-to-dateness and the accuracy at the same time.

Development of an Approach for Analysing Vegetation Community Mosaic Using Landscape Metrics (경관지수를 활용한 식생군락 모자이크화 분석법)

  • Lee, Peter Sang-Hoon;Jeong, Jong-Chul
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.1
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    • pp.161-178
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    • 2017
  • Whereas the demand for development of forested areas covering more than 60% of Korean territory, permission on the forest development has been still given from the perspective of effective land utilization rather than conservation. As the assessment of large forested areas usually focuses more on forest structure, it has its limitation of observing and analyzing the interior change in forest in this way. This study was aimed at computing landscape metrics using a presence vegetation map and FRAGTSTATS 4.2 and analyzing vegetation mosaics. Colonies in native vegetation were classified into a series of major groups and sub-groups based on the native species within the colonies. The colonies were investigated by analyzing a suite of landscape metrics - Core Area, Percentage of Landscape, Number of Patches, Patch Density, Largest Patch Index, Total Edge, Edge Density, Landscape Shape Index, Mean Patch Area, Euclidean Nearest Neighbor. In the Chungnam province major groups and sub-groups of colonies classified based on the proportion of pine and oak species, and pine species was the principal one in terms of distribution area. As for the competition between pines and oaks, while the coverage of pine-centered colonies were three times larger than those of oak-centered ones, pine colonies showed the greater number of patches and therefore higher fragmentation than oaks at the major group level. For the sub-groups, the largest coverage colonies were not only indicated by Pinus densiflora-Quesrcus mongolica colonies among P. densiflora-centered colonies, Q. accutissima colonies among Q. accutissima-centered ones, Q. accutissima-P. densiflora colonies among Q. accutissima-centered ones, Q. mongolica colonies among Q. mongolica-centered ones, P. thumbergii colonies among P. thumbergii-centered ones, and Q. serrata-Q. acutissima colonies among Q. serrata-centered ones, but also revealed more severely mosaicked than other smaller colonies. The overall mosaicking degree estimated by landscape metrics was considered useful for monitoring and investigating vegetation. However, in order to develop management strategy based on analyzing the reason for the mosaicking process and anticipating a trend in vegetation succession, it is essential to further study about ecological characteristics of each colony in the vegetation.

Vegetation Succession and Vegetation Management of the Pinus densiflora S. et Z. Forest in the Beopjusa Area, Songnisan National $Park^{1a}$ (속리산국립공원 법주사지구 소나무림 식생천이와 식생관리 연구)

  • Lee, Kyong-Jae;Ki, Kyong-Seok;Choi, Jin-Woo
    • Korean Journal of Environment and Ecology
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    • v.23 no.2
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    • pp.208-219
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    • 2009
  • This study is to establish a management method for conservation through comparison and analysis on vegetation structures of Pinus densiflora forest around Beopjusa area for past 17-year. The spatial range of the study was $3.6km^2$ from maintenance office to Beopjusa area. The analysis results of the actual vegetation showed that the ratio of vegetation were composed of 64.7% of Pinus densiflora forest, 3.2% of mixed forest of P. densiflora and deciduous broadleaf trees and 5.9% of deciduous broadleaf tree community out of overall area, 360ha. The type of P. densiflora forest were categorized into four communities; community having high potential of succession, community having low potential of it, the community being in the process of succession and community being in the process of natural selection. The succession tendency was in order of the community having low potential of succession(P. densiflora forest), having high potential of it(P. densiflora forest which is deciduous broadleaf trees are dominating in sub-canopy layer), being in the process of succession(P. densiflora-Prunus sargentii and P. densiflora-Quercus serrata community) and being in the process of natural selection(Q. serrata-P. densiflora and Q. aliena-P. densiflora community). In terms of vegetation management, P. densiflora forest having high potential of succession was needed to remove deciduous broadleaf trees in the sub-canopy layer and the community being in the process of succession was required to be pruning the branch in the canopy layer. Lastly, the community being in the process of natural selection was suggested to let it be in succession, since it is hard to be in the status of P. densiflora Forest.