• Journal of the Korean Society for information Management
• /
• v.30 no.4
• /
• pp.215-239
• /
• 2013

Even though the overall scholarly community has recognized a dramatic growth and changes in the Information Science research in Korea over the last few decades, there are still only few studies that have identified the changes in terms of long-term and dynamic point of view. We have analyzed 1,007 IS-research articles from leading Korean journals in KCI (Korea Citation Index), published between 2000 and 2011. To discern the trendline of changes in research interests over time, we conducted a time-series analysis by developing grounded subject scheme from the article set and checking the growth rate of the number of published articles and title keywords. A comparative analysis was also conducted by constructing and comparing co-word maps over time to discover visible changes in research topics over this 12-year period of the IS-research in Korea. As a result, we identified some developments and transformations in major subject areas and knowledge structure of the IS-research in Korea over time. The major trend we discovered is that IS-studies over the 12-year period evolved from system-oriented research to library-application research. The changes are especially observed in knowledge management, Web-based system evaluation, and information retrieval areas. When compared to the results of other studies, the result of our study may serve as an evidence of the localization of Korean IS-studies in the first decade of the $21^{st}$ century.

• Polymer(Korea)
• /
• v.24 no.2
• /
• pp.149-158
• /
• 2000

Oil-absorptive expanded polyurethane (EPU) was prepared with a lypophilic polyol, polypropyleneglycol (PPG) as the soft segment, and toluenediisocyanate (TDI) and $H_2O$ as the hard segment. PPGs haying various average molecular weights ((equation omitted) : 1000, 2000, 3000) were employed to investigate that the soft segment content was consequent on the oil-absorptivity and the mechanical properties of the EPUs. As (equation omitted) of PPG was decreased from 3000 to 1000, the oil-absorptivity and the tensile strength of the EPUs increased from 1460 to 3010% and from 0.26 to 0.55 $kg_{f}$ /$cm^2$ respectively. As the hard segment content ratio, ${\gamma}$ ([NCO]/[OH]) was increased from 1.0 to 1.2, the tensile strength of the EPUs increased from 0.56 to 0.95 $kg_{f}$ /$cm^2$, due to the formation of allophanate and/or biuret bondings. However, as the surfactant (S-A) content was increased from 1.0 to 2.5 pbw, the oil-absorptivity was decreased from 3634 to 3312%, due to the formation of closed cell structures.

• Spatial Information Research
• /
• v.19 no.5
• /
• pp.63-74
• /
• 2011

Recently, there has been much interest in the spatial query which energy-efficiently acquires sensor readings from sensor nodes inside specified geographical area of interests. The centralized approach which performs the spatial query at a server after acquiring all sensor readings, though simple, it incurs high wireless transmission cost in accessing all sensor nodes. In order to remove the high wireless transmission cost, various in-network spatial indexing schemes have been proposed. They have focused on reducing the transmission cost by performing distributed spatial filtering on sensor nodes. However, these in-network spatial indexing schemes have a problem which cannot optimize both the spatial filtering and the wireless routing among sensor nodes, because these schemes have been developed by simply applying the existing spatial indexing schemes into the in-network environment. Therefore, we propose a new distributed spatial indexing scheme of the GR-tree. The GR-tree which form s a MBR-based tree structure, can reduce the wireless transmission cost by optimizing both the efficient spatial filtering and the wireless routing. Finally, we compare the existing spatial indexing scheme through extensive experiments and clarify our approach's distinguished features.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.22-34
• /
• 2004

An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (r=0.827, p<0.01, $R^2$=0.685), elevation (r=-0.637, p<0.01) and slope gradient (r=-0.593, p<0.01). The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.

• Korean Journal of Environment and Ecology
• /
• v.28 no.4
• /
• pp.442-449
• /
• 2014

This study was carried out to measure the seasonal changes in community structure and species composition of marobenthos on the subtidal area of Saemangeum regions. The macrobenthos comprised 64 species were during this study, predominately annelids (53.0%), arthropods (18.8%), mollusks (18.8%) and 9.4% were from other species. Total abundance was 24,885 individuals, comprising 19,805 individuals of annelids (79.6%), 4,620 individuals of mollusks (18.5%), 295 individuals of other species (1.2%), and 165 individuals of arthropods (0.7%). After analyzing the bray-curtis similarity, had two large groups (A, B) the inside and outside of Saemangeum dike. They all matched the nMDS analysis. I evaluated the benthic community health using BPI (Benthic pollution Index). There are no significant differences between the station position and the inside or outside of Saemangeum dike. But, highest BPI level was in March.

• Journal of the Korean Geotechnical Society
• /
• v.33 no.3
• /
• pp.49-62
• /
• 2017

In order to understand response of geo-structures to the freezing-thawing process in the ground, it is necessary to consider phase change of the pore water of the ground and also to understand soil interaction with structures. In this study, numerical analysis was carried out for freezing and thawing effect on the modular road system. Neumann's theoretical equation for freezing-thawing processes in porous media can be used to estimate frozen depth and heaving from basic soil properties and ground and surface temperature, but its application is limited to the case for the sediment with fully saturated condition and zero unfrozen water content. Numerical analysis of the modular road system was performed on various soil types and different ground water table as the varying freezing index. The amount of heaving in the silty soil was much larger than those in granite weathered soil or sandy soil, and lowering groundwater level reduced ground heaving induced by freezing. Numerical analysis for temperature history of the ground surface predicted residual heaving near the surface by the freeze-thaw process in silty soil. It ought to reduce stiffness and bearing capacity of the ground so that it will impair stability and serviceability of new road system. However, the amount of residual heaving was insignificant for the road system installed in weathered soil granite and sandy soil. Since modular road system is a pavement structure mounted on the supporting substructure unlike the prevalent road pavement system, strict criteria should be applied for uniform and differential settlement of the pavement system.

• Journal of the Korean earth science society
• /
• v.24 no.8
• /
• pp.657-667
• /
• 2003

Deep-drilled core sampling and high-resolution seismic survey were carried out to identify a Holocene-late Pleistocene boundary in Gyeonggi Bay, western coast of Korea. Analysis of core sections revealed the existence of an oxidized and semi-consolidated sediment layer, Iying immediately below a Holocene horizon (Unit I) and being developed at the top of a late Pleistocene deposit (Unit II). The oxidized sedimentary layer (uppermost part of Unit II) is characterized by semi-consolidated, yellowish sediments showing signs of desiccation and alteration such as high N value, low water content, periglacial cryogenic structure, depletion of smectite, and high geochemical weathering index (Ba/Sr ratio). This feature, together with radiocarbon ages, suggests that the layer has formed as a result of prolonged subaerial exposure of Unit II sediments during the late Wisconsin sea-level lowstand, producing a regional unconformity. Such unconformitic-bounding surface corresponds to a prominent near-surface reflector (R), which is observed in seismic profiles obtained across the drilled-core sections in the study area. Consequently, the buried oxidized-sedimentary layer associated with the seismic reflector possibly plays a key horizon for the understanding of late Quaternary environmental changes as well as evidence of the emergence of the Yellow Sea shelf during the late Wisconsin sea-level lowstand.

• Journal of the Korean Academic Society of Industrial Cluster
• /
• v.4 no.1
• /
• pp.14-50
• /
• 2010

This study focused on the competitiveness analysis of industrial cluster using econometric method and competency analysis method to measure the situation of Seocho-gu industrial cluster and Yangjae R&D cluster at Seoul. The econometric method used the data such as the number of firms, the number of employee, GRDP. The competency analysis method measured the level of agglomeration of cluster for years through LQ(Location quotient) index. In addition, the characteristics and structure of each industry in Secho-gu and Yangjae-dong R&D cluster. The circumstance of location and business, the competency of potential ability of industries were analysed by SWOT. In sum, this study has the following conclusion. First, Seocho-gu and Yangjae-dong region has an advantage in the circumstance for R&D related industry and man power. Second, Seocho-gu and Yangjae-dong region has a good potential for development in R&D related industries. These region has a good relationship the four major R&D related industry of Seoul. Third, these region also has a advantage in the potential development of R&D related researchers in the corresponding industries.

• Journal of Korean Society of Forest Science
• /
• v.102 no.3
• /
• pp.446-454
• /
• 2013

The present study investigated the biological agents and environmental conditions of the habitats of the Kirengeshoma koreana, a class 2 endangered species class according to the South Korean Ministry of Environment (MOE), elucidated the structural characteristics of the forest stands in the habitats with the importance value and the diversity index, conducted comparative analysis of the factors, and explored their relationship with environmental factors. According to the results of direction analysis of natural habitats of the Kirengeshoma koreana, the direction was distributed to the north or the northeast, and the slope amounted to $15-40^{\circ}$, thus demonstrating that the slope has little effect. In addition, the results showed that the distribution of Kirengeshoma koreana populations dramatically increased starting in areas at least 600 m above the sea level and that the relative light intensity was 3.79% on an average. Most populations were native to gorges and crevices between rocks so that they mainly tended to inhabit areas that could see soil loss in times of precipitation. In addition, a considerable number of the populations were close to hiking trails as well, thus leading to concerns about their artificial destruction. The soil of layer a in the main growth space of the Kirengeshoma koreana was analyzed and turned out to be strongly acidic, measuring pH 4.45-4.89 (average: 4.68). All investigation sections were typical natural broad-leaved tree areas, and, judging from the fact that the Kirengeshoma koreana was most likely to appear in colonies of the Mongolian oak tree (Quercus mongolica Fisch. ex Ledeb.), the Mongolian oak tree seems to be the species of tree that has the greatest effect on the inhabitation of the Kirengeshoma koreana.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.1
• /
• pp.114-125
• /
• 2009

In this study, a design value analysis technique that considered stochastic LCC and stochastic performance evaluation was proposed, and by introducing the concept of reliability analysis, a decision making that secured reliability was supported. The results of this study, which was carried out according to the above objectives and methods, are summarized as follows: 1) The design value analysis procedures and value state function, improved in order to carry out a reliable analysis when evaluating alternate proposals that were extracted after the function definition was complete, were formalized, and in order to secure consistency and efficiency for value evaluation procedures, an evaluation index scheme was proposed; 2) Database collection and analysis were done for a bridge's LCC analysis. As for the collection scope of data, literature of previous research done on a bridge's LCC analysis was used as the basis for analysis, and for securing reliability regarding analysis results and dealing with uncertainty of collected data, the MCS technique was applied; 3) Weights and evaluation ranks for performance evaluation of each of the alternate proposals, as well as LCC analysis model, analysis period, discount rate, user expense, safety inspection and safety diagnosis expense conditions for LCC analysis were proposed. Lastly, a feasibility study was done and conclusion was made about "OO grand bridge and connecting road construction work execution design" project centered on value analysis execution case.