• Journal of Korean Society for Geospatial Information Science
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• v.21 no.3
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• pp.27-35
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• 2013

This study intends to analyze the accessibility to the evacuation shelters according to pedestrian characteristics for Shinpo-district and Haewoon district, Masan Happo-gu, Changwon, designated as Disaster Risk Districts(Typhoon and Storm Surge Risk Zones) due to the typhoon and surge disasters of the past such as Typhoon RUSA or MAEMI. Evacuation speed was analyzed by dividing the types of evacuees into children, general adults, and the aged people by considering physical conditions. In the case of Haewoon district, currently designated evacuation shelters appeared to be appropriate. But in the case of Sinpo district, over 50% of designated Disaster Risk Districts appeared to be evacuation-vulnerable zones in the case of the aged. Therefore, three additional shelters were designated to complement these problems. The results reveal that the problems about the evacuation-vulnerable zones in the case of the existing designated shelters, appeared to be improved. It is expected that the results, obtained in this study will be utilized to establish the complementary measures to analyze the evacuation risk and solve the problems.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.1
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• pp.103-118
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• 2018

Ecosystems in subalpine regions are recognized as areas vulnerable to climatic changes because rainfall and the possibility of flora migration are very low due to the characteristics of topography in the regions. In this context, habitat niche was formulated for representative species of arbors in subalpine regions in order to understand the effects of climatic changes on alpine arbor ecosystems. The current potential habitats were modeled as future change areas according to the climatic change scenarios. Based on the growth conditions and environmental characteristics of the habitats, the study was conducted to identify direct and indirect causes affecting the habitat reduction of Abies nephrolepis. Diverse model algorithms for explanation of the relationship between the emergence of biological species and habitat environments were reviewed to construct the environmental data suitable for the six models(GLM, GAM, RF, MaxEnt, ANN, and SVM). Weights determined through TSS were applied to the six models for ensemble in an attempt to minimize the uncertainty of the models. Based on the current climate determined by averaging the climates over the past 30years(1981~2010) and the HadGEM-RA model was applied to fabricate bioclimatic variables for scenarios RCP 4.5 and 8.5 on the near and far future. The results of models of the alpine region tree species studied were put together and evaluated and the results indicated that a total of eight national parks such as Mt. Seorak, Odaesan, and Hallasan would be mainly affected by climatic changes. Changes in the Baekdudaegan reserves were analyzed and in the results, A. nephrolepis was predicted to be affected the most in the RCP8.5. The results of analysis as such are expected to be finally utilizable in the survey of biological species in the Korean peninsula, restoration and conservation strategies considering climatic changes as the analysis identified the degrees of impacts of climatic changes on subalpine region trees in Korean peninsula with very high conservation values.

• Land and Housing Review
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• v.3 no.1
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• pp.97-109
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• 2012

For the design of underpass structures, -1.0m(G.L) ground water level guideline for the design of railway, subway, utility tunnel etc, is still being used in Korea. As a result, the underpass structure can be forced by buoyancy, and therefore the in-situ buoyancy anchor method is usually being applied to prevent the uplifting force. For the Yeongjongdo sky city project, the drainage method was applied to remove the buoyancy force. In this study we estimate the efficiency and safety of the applied design and propose the detailed guidelines for standard design and maintenance of the guided drainage technique. Especially, the auxiliary pumping well was operated to maintain the ground water level around the underpass. In the study site, the applied guided drainage method has advantages in both engineering and economic aspects.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.461-470
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• 2018

Beyond river restoration focused on the inside region of main streams up to now, the river restoration including the outside region of streams has been started recently. As a part of this attempt, the restoration of abandoned rivers has been tried, but the development of a suitable model to quantitatively assess the improvement of hydraulic and ecological connectivity is not still satisfying. In this study, a grid - based hydraulic analysis model to evaluate the recovery of ecological connectivity through the restoration of abandoned rivers has been developed. In order to examine the applicability of this model, the ecohydaulic connectivity of the Cheongmi River Project area in Notap region was evaluated. This model can promptly and simply analyze the temporal and spatial distribution of the hydraulic and ecological characteristics, and it can be used as a appropriate tool to assess the hydraulic and ecological connectivity in the future.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.401-414
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• 2016

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia anthina PSB-15 and Enterobacter aerogenes PSB-16, was assessed in liquid medium and green gram plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($519{\mu}g\;mL^{-1}$) into the medium, followed by single inoculation of Burkholderia strain ($492{\mu}g\;mL^{-1}$) and Enterobacter strain ($483{\mu}g\;mL^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production, and glucose consumption were observed in the culture medium co-inoculated with PSB-15 and PSB-16 strains rather than that of single inoculation. Based on the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 9% and 8% higher shoot and root growth, respectively, compared to the control. Therefore, in conclusion, co-inoculation of the strains B. anthina and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, considering the short assessment period of the present study, we recommend engaging in further work under field conditions in order to test the suitability of these strains as bio-inoculants.

• Journal of the Korean Society for Railway
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• v.17 no.6
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• pp.433-442
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• 2014

This paper evaluates the performance of transit assignment algorithms for urban rail networks. The accuracy of the algorithms is essential not just for travel forecasting but also for the area of applications such as the assessment of road vulnerability and the fare adjustments between train operating companies. Nonetheless, the suitability and caveats for the series of computational steps have not yet been much discussed. This study thus considers the characteristics that are appropriate for investigating Seoul rail travelers using three representative transit assignment algorithms: the optimal strategy algorithm, route choice algorithms, and the Dial's algorithm. Both the theoretical foundation and the empirical performance are examined. The results demonstrate that the Dial's algorithm is superior in terms of the theoretical soundness and the computational efficiency.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.117-121
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• 2013

Single or co-inoculation of phosphate solubilizing bacterial and fungal strains (Burkholderia anthina and Aspergillus awamori respectively) was performed separately to assess their synergistic and antagonistic interactions and the potential to be used as bio-inoculants. Co-inoculation was found to release the highest content of soluble phosphorus (1253 ${\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of fungal strain (1214 ${\mu}g\;ml^{-1}$) and bacterial strain (997 ${\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of fungal strain and co-inoculation of fungal and bacterial strain in terms of the phosphorous release. The highest pH reduction, organic acid production and glucose consumption were observed in the sole A. awamori inoculated culture medium. According to the plant growth promotion bioassays, co-inoculation of the microbial strains resulted in 21% and 43% higher shoot and root growth of the mung bean seedlings respectively as compared to the respective controls. Therefore, co-inoculation of B. anthina and A. awamori showed better performance in stimulating plant growth than that in inoculation of each strain alone. However, assessment period of the present study being short, we recommend in engaging further experimentation under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.143-151
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• 2009

Forest type map is a main forest thematic map which shows forest type, age class, diameter class and density. This map has been used as a base data in various fields such as forest policy decision-making, land suitability assessment and eco map production etc. But the existing map had many kinds of errors and no metadata because there was no standard for digital map production. On this study, we developed standard for digital forest type map production consisting of 33 unit processes including DB schema design, mapping process, quality control and metadata input process. Based on this standard, country-wide digital forest type map can be produced with consistent quality and standard metadata.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.1-11
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• 2021

Soil moisture plays a critical role in hydrological processes, land-atmosphere interactions and climate variability. It can limit vegetation growth as well as infiltration of rainfall and therefore very important for agriculture sector and food protection. Recently, due to the increased damage from drought caused by climate change, there is a frequent occurrence of shortage of agricultural water, making it difficult to supply and manage stable agricultural water. Efficient water management is necessary to reduce drought damage, and soil moisture management is important in case of upland crops. In this study, soil moisture was calculated based on the water balance model, and the suitability of soil moisture data was verified through the application. The regional soil moisture was calculated based on the meteorological data collected by the meteorological station, and applied the Runs theory. We analyzed the spatiotemporal variability of soil moisture and drought impacts, and analyzed the correlation between actual drought impacts and drought damage through correlation analysis of Standardized Precipitation Index (SPI). The soil moisture steadily decreased and increased until the rainy season, while the drought size steadily increased and decreased until the rainy season. The regional magnitude of the drought was large in Gyeonggi-do and Gyeongsang-do, and in winter, severe drought occurred in areas of Gangwon-do. As a result of comparative analysis with actual drought events, it was confirmed that there is a high correlation with SPI by each time scale drought events with a correlation coefficient.