• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.365-373
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• 2016

Much of the data used in the analysis of environmental ecological data is being obtained over time. If the number of time points is small, the data will not be given enough information, so repeated measurements or multiple survey points data should be used to perform a comprehensive analysis. The method used for that case is longitudinal data analysis or mixed model analysis. However, if the amount of information is sufficient due to the large number of time points, repetitive data are not needed and these data are analyzed using time series analysis technique. In particular, with a large number of data points in the current situation, when we want to predict how each variable affects each other, or what trends will be expected in the future, we should analyze the data using time series analysis techniques. In this study, we introduce univariate time series analysis, intervention time series model, transfer function model, and multivariate time series model and review research papers studied in Korea. We also introduce an error correction model, which can be used to analyze environmental ecological data.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.90-98
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• 2008

Nanotechnology(NT) refers to a field of advanced micro-technology covering the creation and manufacturing of materials on the atomic and molecular scale and requires interdisciplinary study with various fields including materials science, physics, chemistry, electronics and others. Whileas nanotechnology is a kind of micro and small scaled science, space technology(ST) is one of the larger and system technologies utilizing broad fields of mechanical, materials, electronics and communication technologies. It is necessary to select and concentrate the functional items of nanotechnology for efficient application to be utilized in space technology, due to the cross-sectional characteristics of nanotechnology within nanomaterials, nanoelectronics, and nanomanufacturing. This paper provides the current state of art of nanotechnology in space technology by evaluating NASA's activities and the 9th frame of the project ANTARES(Analysis of Nanotechnology Applications in Space Developments and Systems) with the support of the German Aerospace Center (DLR), Space Flight Management, Division Technology for Space Systems and Robotics. It has shown that it is necessary to apply nanotechnology to space technology in order to achieve international competitiveness, for the nanotechnology can bring the previously impossible things to reality. Since KARI plans to send an unmanned probe to the moon's orbit and land a probe on the moon's surface in 2025, it is urgently needed to incorporate nanotechnology to national space development plan.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.307-314
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• 2000

This study is to investigate the recurrence characteristics of wet and dry years using over 200 year records of annual rainfall depth including Chosun Age in Korea. As well as analyzing the correlation structure of the raw data, recurrence trends of wet and dry year has been investigated based on several truncation levels (mean, $mean{\pm}0.25stdv.,\;mean{\pm}O.5stdv.,\;mean{\pm}O.75stdv.,\;mean{\pm}stdv.$). Also the transition probability among wet, dry and normal years has been derived for the same truncation levels. and finally the average return periods based on the steady-state probabilities were obtained. This analysis has been applied to not only the entire data but also partial data set of before- and after-the long dry period around 1900 in order to compare and detect the possible difference between the Chukwooki (an old raingauge invented in Chosun age) and the modem flip-bucket style. As a result, Similar pattern of dry and wet year recurrence has been found, but the return period of extremely dry years after the dry period shown longer than that before the dry period. Assuming that the dry and wet years can be defined as $mean{\pm}$ standard deviations, respectively, the return period of the wet years is shown to be about 5~6 years and that of the dry years about 6~7 years.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.741-749
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• 2017

This study aims to provide the technical considerations and implications for the development of soil vulnerability assesment tool based on the review of existing tools and case studies applied both domestically and internationally. For this study, we specifically investigated the basic theories and major features implemented in the screening models abroad. In contrast, one case study of prioritizing the vulnerable districts was presented to identify the research trends in Korea. Our literature review suggested that the characteristic of target areas and contaminants needed to be properly incorporated into soil vulnerability assessment because the current tools in Korea neglected these properties which prevented this tool from being used as a correct measure of soil management and prevention. We also reached the conclusion that in terms of technical aspect, the soil vulnerability assessment tool should be developed based on the physical theory and environmental data that were varied over space and time so that the end-users were able to readily and effectively screen soil vulnerability over large areas. In parallel with technical improvement, great effort needed to be devoted to develop an integrated environmental information system that increased the availability of data and shared various types of environmental data through enhanced multi-agency collaboration.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.87-97
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• 1997

In this research, photo images of uncultivated marginal lands were simulated to visualize alternative land use patterns using image capture technology. Based on an original photos, 3 simulated images were created ; barren condition, aforested condition and shrub-covered condition. The simulated images were then used to evaluate respondents' visual preference(SBE value) and willingness to pay for the agricultural development tax as a hypothetical payment vehicle. The SBE values for barren condition are the lowest, as expected. When original condition is changed to forested or shrubbed, the SBE values are increased significantly. The logistic models for the willingness to pay for the various alternative land uses performed significantly, ${\rho}$ statistics for 6 models ranges from 0.3 to 0.4 and correct percentage for predicted probability are about 75%. Among independent variables, the amount of tax offered is the most influencing factor to predict the probability. Income also shows some relationship with no statistical significance. Other variables behave inconsistently in the model. When SBE and WTP are correlated, rather consistent trends can be observed. With the increase of SBE, WTP predicted by the model increases accordingly. It can be concluded that enhancement of scenic quality of the agricultural lands leads to increase of people's willingness to pay to support the rural environmental conservation.

• Korean Business Review
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• v.13
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• pp.107-132
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• 2000

The entry of large discount stores such as E-mart, LG mart, Magnet etc. into small cities have had a profound impact on the business of small-sized retailers. Now, it becomes the matter of survival for small-sized retailers and it is almost impossible to reverse those trends. Without satisfying consumers' various needs and wants, retailers can not survive. Therefore, it is extremely important to understand retail competition from the perspective of consumers in order for retailers to survive in the turbulent environment. The previous research studies on retail competition have focused on the comparison among different types of retailers with respect to strategic retail mix variables. However, they do not consider the competitive aspects of consumers' sides. In addition, we do not fully understand the meaning of "shopping." Shopping means hedonic shopping as well as utilitarian shopping. Utilitarian aspects are important but consumers also prefer' hedonic aspects too. That is the reason that traditional retailers such as small-sized retailers can not compete with modem and large retailers. We use three different methods to identify the macro and competitive structure. of retailing with respect to shopping. Factor analysis, multidimensional scaling, and multiple correspondence analysis are used to produce perceptual mapping of retail competition. Department store and large discount store are identified as close competitors but both might have an indirect impact on small-sized retailers through demand shift toward high end retailers.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.2
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• pp.203-221
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• 2020

This study closely analyzed changes in the educational environment and changes in the needs of children's and young people's reading culture programs, which are directly beneficiaries of the promotion of reading culture as they enter the fourth industrial revolution. It also comprehensively evaluated the reading culture promotion project for children and adolescents promoted by the National Children and Youth Library and proposed a reading culture promotion project that meets the needs of the smart era. This study investigated the cases of various domestic and foreign reading culture promotion projects to divulge trends. The authors invited experts from public libraries and school libraries with experience of the reading culture promotion projects and performed Focus Group Interviews (FGI). The authors evaluated individual reading culture program based on the PDCA method (Plan, Do, Check, Act). Based on the data obtained through case studies and expert evaluations, the development plan of reading culture promotion project and the strategy of promoting new projects to be pursued in the National Children and Youth Library were presented. By gathering the results of the research, 'Interactive e-book making platform production / distribution business', 'Game-type reading program production / distribution business', 'Habruta reading culture dissemination project using backward learning method', 'Youth coding branding "Teen-Start -Up"' were proposed as new services.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.65-71
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• 2017

LNG is being spotlighted as a clean marine fuel because of recent trend in reinforcement of marine environmental regulation. In this paper, demand prospect of LNG bunkering for Ulsan port is carried out to analgize the possibility of commercialization of floating LNG bunkering terminal. Environmental analysis for LNG bunkering and LNG bunkering trends of competitive ports in the world are considered to draw out the prospection of LNG bunkering demand in Ulsan. As a result, car carrie and oil carrier were expected to have more possibility in switching to LNG fuelled ship. The LNG bunkering demand in Ulsan. As a result, car carrier and oil carrier were expected to have more possibility in switching to LNG fuelled ship. The LNG bunkering demand in Ulsan port was expected to be about from 650,000 ton to 900,000 ton in 2030 and Ulsan port is prospected to be a good port for FLBT business in th future.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.223-236
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• 2019

Resistivity surveys can identify the distribution of geological units and structures (including fragmented fault zones), the extent of weathered and modified geological strata, and the characteristics of groundwater. This study aims to analyze the underground sedimentary layers and geological structures near the Nari and Albong Basins of Ulleung-do, Korea, focusing on six survey lines to identify the spatial trends in subsurface resistivity. A modified dipole array method (D method) was employed, combining resistivity results obtained by existing dipole array methods (A and C methods). The modified method provides optimal analysis of the cross-section of underground resistivity, and shows a clear boundary between a low-resistivity zone (${\leq}500{\Omega}{\cdot}m$) of sedimentary layers and weak zones, and a high-resistivity zone (${\geq}5,000{\Omega}{\cdot}m$) of volcanic rock (trachyandesite). The estimated average thickness of the sedimentary layers is 50~100 m for the Albong Basin and 100~200 m for the Nari Basin. An anomaly zone, different from the weak zone in the bedrock, is identified as a caldera fault, and the low-resistivity zone extends from the surface down to the lowest survey depths.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.419-430
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• 2021

This study investigated spatiotemporal trends of sediment-related disasters in North Korea from 1960 to 2019 and post-disaster recovery cases based on a literature review and satellite images. Results showed that occurrence status of sediment-related disasters was initially externally reported in 1995 (during the Kim Jongil era); their main triggering factor was heavy summer rainfall. Furthermore, forest degradation rate was positively correlated with population density (R² = 0.4347, p = 0.02) and occurrence number of sediment-related disasters was relatively high on the west coast region, where both variables showed high values. This indicates that human activity was a major cause of forest degradation and thus, significantly affected sediment-related disasters in mountain regions. Finally, sediment- related disasters due to shallow landslides, debris flow, and slow-moving landslides were observed in undisturbed forest regions and human-impacted forest regions, including terraced fields, opencast mines, forest roads, and post-wildfire areas, via satellite image analysis. These disaster-hit areas remained mostly abandoned without any recovery works, whereas hillside erosion control work (e.g., treeplanting with terracing) or torrent erosion control work (e.g., check dam, debris flow guide bank) were implemented in certain areas. These findings can provide reference information to expand inter-Korean exchange and cooperation in forest rehabilitation and erosion control works of North Korea.