• Spatial Information Research
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• v.14 no.1 s.36
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• pp.163-176
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• 2006

The concept of 'spatial association' explains spatial distribution pattern of geographical phenomenon based on similarity with neighborhoods, as in the Tobler's Law of Geography: 'Everything is related to everything else, but near things are more related than distant things.' In this study, we develop a time-series exploratory analysis tool for discovering temporal patterns of spatial association by combining spatial statistics and geo-visualization, and thus present a possibility to support spatial decision-making process. As for the spatial proximity weight matrix indispensable to measuring global and local spatial association, we employ a variety of flexible weighting schemes using geometric characteristics of areal unit. In addition, we renovate the existing visualization methods for more effective understanding of the procedures and results of time-series analysis on spatial association: for instance, temporal parallel coordinate plot with box plot, animated map for spatial association, and 3D Moran scatterplot. The feasibility of our system is verified by time-series analysis experiments on the spatial association of land price fluctuation rate for all administrative units in Korea, $1995{\sim}2004$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.713-719
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• 2001

The aim of this study is to check the application criteria of the conventional techniques and clarify the effects of breaker depth, seabed conditions on the stability in relation to the effects of uncertainty of storm duration and directional irregular waves. The typical damage modes were divided by the direct wave force on the armor unit and by the local scouring around the toe of a breakwater head by the model experiments. The destruction modes are defined, and some criteria on the damage modes and scouring/deposition at the toe of a breakwater head in relating the wave-bottom-structural conditions can be checked using the multi-directonal irregular wave generator system. According to the results, it is emphasized that the 3-D effects on the stability should be analyzed in the design of multi-purpose/function coastal structures in consideration of the evaluation of spatial variation of damage modes and hydraulic characteristics as well as the wave distribution along the structures.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.23-28
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• 2007

Auxin-producing antagonistic bacterium K11, which can inhibit Phytophtora capsici, was isolated from a local red-pepper field soil in Gyeong-buk. In order to check for additional PGPR(plant growth promoting rhizobacterium) functions of the strain K11, we confirmed siderophore and cellulase productions by CAS (chrome azurol S) blue agar and CMC plate with congo red, respectively. The strain K11 was identified as Bacillus licheniformis with 98% similarity on 16s rDNA comparison and Biolog analyses. B. licheniformis K11 promoted mung bean adventitious root induction and enhanced root growth of mung bean (160%), pea (150%), and Chinese cabbage (130%), Also, B. licheniformis K11 was able to effectively suppress (63%) P. capsici causing red-pepper blight in the pot in vivo test. Therefore, we could select a triple-functional PGPR which has auxin, siderophore, and cellulase producing ability for effective crops production in organic farming.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.369-376
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• 2009

Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.

• Ocean and Polar Research
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• v.41 no.3
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• pp.169-181
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• 2019

The purpose of this study is to develop geochemical tracers to identify a specific source desert of mineral dust in China using the published data. In addition, we tested the applicability of these tracers to wet-deposits and soil samples collected in Jeju, Korea. Because of similarity in trace elemental compositions of mineral dust from the major arid regions in China, such as Taklimakan, West Ordos (Badain Jaran), East Ordos (Mu Us and Hobq), East Northern China (Horqin), West Northern China (Gurbantunggut), and Chinese Loess Plateau, there has been limited to the use of geochemical data for source identification. Here we propose the four (4) plots using combination of seven (7) geochemical variables as a source indicator to distinguish one from other source regions in China: $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$, where $_N$ and $\(\frac{Ce}{Ce}\)_N^*$ stand for values normalized to Post-Archean Average Shale composition and Ce anomaly, respectively. Mineral dusts from aforementioned six major deserts are distinguished one from the others by the combined use of these variables. Jeju rock and soil samples form a separate domain from Chinese mineral dusts in all four plots. In contrast, most of Jeju dust samples were comparable with the West Ordos desert (Badain Jaran) domain, indicative of strong influence of Badain Jaran dust in Jeju in spring season when the mineral dust was collected. A weak positive Ce anomaly in Jeju samples implies minimal local contribution. Our study suggests that the combination of $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$ can be used to identify a specific source region of mineral dust in China as well as Jeju mineral particles.

• Knowledge Management Research
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• v.22 no.2
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• pp.227-246
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• 2021

In the context of the global pandemic caused by COVID-19, emergency alert text messages can violate the privacy of confirmed corona positive cases. This study used conjoint analysis to identify the essential information factors and the privacy invasion information factors of local government initiated safety notices. As a result of this study, we found eight essential information factors, including all routes of the confirmed case and ten privacy invasion factors of safety notices. In addition, we found that there is a similarity between the combinations of information perceived to be the most essential and perceived as the most significant privacy invasion; both combinations include the confirmed case's personal and route information. This study ultimately tried to suggest a way to lower the concern about privacy invasion of the confirmed cases without damaging the emergency alert text messages' essential information. We expect that this study will provide researchers and policymakers interested in disaster communication with valuable theoretical and practical implications.

• Journal of Environmental Impact Assessment
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• v.30 no.4
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• pp.237-246
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• 2021

The similarity of hourly PM₁₀ and PM_2.5 concentration profiles of the atmospheric monitoring stations in Gyeonggi-do was evaluated through the multilateral analysis between stations. The existing category for most stations in the regions shows relatively low Pearson correlation values of 0.68 and 0.7 for PM₁₀ and PM_2.5 on average respectively, and some monitoring stations revealed high relationships over 0.8 to other regions. Since the current regions are mainly categorized by cluster analysis based on the number of occurrence of high concentration events and geological factors, it is necessary to reclassify them by concentration characteristics for precise fine dust management. In accordance, multi-dimensional scaling being able to visualize could categorize the regions based on regional emission contribution rate and hourly fine dust concentration. As a result of the current analysis, PM₁₀ and PM_2.5 could be reclassified into five regions and fourregions, respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.59-71
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• 2022

This study considered regional differences in the university-industry collaboration of Korean universities and performed cluster analysis to identify the spatial range with high university-industry collaboration connectivity. By university establishment type, it was found that the university-industry collaboration capacity of the major national university was superior overall, especially in the technology transfer & commercialization sector and the infrastructure sector, compared to private universities and general national universities. The spatial pattern of university-industry collaboration capacity showed relatively clear differences by city and province. In terms of university-industry collaboration capacity by sector, it was confirmed that the regional gap was not large in the talent training sector and the infrastructure sector, but the regional gap was relatively large in the technology transfer & commercialization sector and the start-up sector. As a result of the cluster analysis to identify a spatial range with high connectivity in terms of similarity and spatial proximity of university-industry collaboration patterns, it is divided into 15 clusters. It is found that most of major national universities are included in one of 15 clusters where all sectors of university-industry collaboration are strong. Therefore, as a policy measure to achieve regional innovative growth through enhancing the effectiveness of university-industry collaboration, we propose the establishment of a hub & spoke network-type collaboration system in which a major national university acts as a hub and nearby local universities play a spoke role.

• Tunnel and Underground Space
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• v.33 no.1
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• pp.57-69
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• 2023

In this study, we simulated induced seismicity in the Groningen natural gas reservoir using 2D hydro-mechanical coupled discrete element modelling (DEM). The code used is PFC2D (Particle Flow Code 2D), a commercial software developed by Itasca, and in order to apply to this study we further developed 1)initialization of inhomogeneous reservoir pressure distribution, 2)a non-linear pressure-time history boundary condition, 3)local stress field monitoring logic. We generated a 2D reservoir model with a size of 40 × 50 km² and a complex fault system, and simulated years of pressure depletion with a time range between 1960 and 2020. We simulated fault system failure induced by pressure depletion and reproduced the spatiotemporal distribution of induced seismicity and assessed its failure mechanism. Also, we estimated the ground subsidence distribution and confirmed its similarity to the field measurements in the Groningen region. Through this study, we confirm the feasibility of the presented 2D hydro-mechanical coupled DEM in simulating the deformation of a complex fault system by hydro-mechanical coupled processes.

• Design Convergence Study
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• v.16 no.4
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• pp.1-16
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• 2017

As the local manufacturing industry has entered a phase of stagnation, service and product design based on user experience has been highlighted as an alternative for the innovation. However, SMEs(Small and Medium-sized Enterprises) are still struggling to overcome the current crisis. One of the reasons is that SMEs do not have enough contact points with the validated UX firms and experts. Thus, SMEs has a high barrier to invest in new opportunity area, user experience. In this study, we aim to figure out UX experts' competence to perform the UX method to solve the UX problems based on the KSA framework(Knowledge, Skill, Attitude). Based on the literature review and expert workshop, we grouped the UX method according to the similarity of the competence required to conduct the method. With cluster analysis, 5 different groups of UX method were defined based on the competence, Panoramic Analysis, Meticulous Observation and Analysis, Intuitive Interpretation, Agile Visualization, and Logical Inspection. The results would be applied to compose a portfolio of UX experts and to implement a mechanism that could recommend the professional experts to the company.