• Journal of the Korean Geotechnical Society
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• v.28 no.1
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• pp.55-66
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• 2012

The load transfer mechanism of hybrid model of soil-nailing and compression anchor is studied in this paper. The hybrid model is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. It can make active behavior of skin friction by applying the pre-stress. In this paper, the load transfer mechanisms of soil-nailings, compression anchors, and hybrid models, respectively, are obtained from skin friction theory and load transfer theory. Field pullout tests are performed to identify the load transfer mechanism and experimental results are compared with analytical solution. In case of soil-nailings, the tension load is transferred from face to tip, however, in case of compression anchors, the compression load is transferred from tip to face. The experimental behavior of the hybrid model is similar to that of compression anchor when only pre-stress is applied. If the pullout test is performed by simultaneously pulling out the anchor and the nail, the compression load is dominant at the tip and tension load is dominant at the face. The load transfer mechanism of the hybrid model shows the combined behavior of soil-nailings with compression anchors.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.53-60
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• 2004

Congestion index is needed for quantifying congestion level for various areas. So far, the index has been calculated based on multiple vehicle data for specified time interval. Such being the case, it was costly to build it and the usage of it was focused on policy development and evaluation rather than on traffic information provision. This study focuses on a development on a single vehicle based congestion index which can be a representative value for link congestion level and link speed information at the same time for dual purposes of traditional usages and information provision. A new term has been added for representing real time based arterial congestion level and it has been verified on a real time basis. The index was based on single vehicle GPS data and seemed to be cost effective in deriving the index. With the help of the index, the traffic information contents can be diversified in a constructive way in providing real time traffic information for ITS area and in using congestion level determination for traditional transportation areas.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.287-296
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• 2020

Mine Reclamation Project is being carried out with the aim of ensuring a sustainable green living and helping to develop eco-friendly mines by analyzing, removing and preventing the harmful factors. Mines developed during the japanese colonial period and mining boom period are still not repaired throughout the country, and from these scattered risks, public safety is worth pursuing as a top priority. The project that is close to public safety in the mine recalmation project is an emergency treatment, and the most widely used method is a filling method similar to the ground subsidence prevention. If dangerous mine cavity or tunnels are located in the mountains, charging with existing materials may not be possible, or unreasonable cases may occur, and new methods of technological development are required. Emergency actions should be carried out safely and efficiently to prevent the loss of precious people's lives on the hiking paths adjacent to dangerous mining sites. In these field conditions, urethane foam materials may be an alternative. In this study, the applicability of urethane foam materials in mining was reviewed through overseas cases. It was also tested on the appropriate depth of top soil for the protection of urethane foam materials through forest fire simulation test. The test result show that approximately 15cm of soil covering (recommended 20cm over) was suitable for maintaining the function of foam materials from forest fires.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.217-226
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• 2019

Optimum engineering methods for bank protection were classified based on steepness of bank slope and an existence of waterfront facility in the floodplain, and a new concept of eco-hybrid rolling mat method which could be applicable for the unfitted cases with previously developed countermeasures was suggested in this study. The eco-hybrid rolling mat method can be constructed while maintaining the river environment and ecosystem that does not interfere with the ground and slopes, when bank erosion occurs, it is an economical and efficient construction method that can protect the revetment and the bank slope immediately. The developed eco-hybrid rolling mat method was verified for the designed structure, system, function and effect based on large-scale river experiments including field exposure and decomposition test. As a result, the normal operation and effect of the rolling mat ted under low and high velocity conditions were confirmed with respect to bank protection. The effect of bank erosion prevention was quantitatively validated by sediment concentration monitoring and analysis, and the product specification of the eco-hybrid rolling mat was presented based on the standardized mat applied in real-scale tests.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.304-313
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• 2019

Biopolymer based on microbial β-glucan and xanthan gum is effective for vegetation and has a function of enhancing soil strength, which can be used as soil reinforcement and stabilization materials in river embankment. The purpose of this study is to verify the vegetation effect of the surface of levee by biopolymer with seed spraying method. Mixed soils with biopolymer were used to cover the surface of embankments. The strength is higher in biopolymer-treated soil and xanthan gum based biopolymer has advantage for quality control in field scale. In addition, the vegetation of F. arundinacea and L. perenne showed various reactions with types of biopolymers. Biopolymer has a positive effect on the vegetation of them. In contrast, root growth tended to decrease in biopolymer-treated soils. The results indicate that root growth is slow down due to increasing ability to retain water in biopolymer-treated soil. In order to apply biopolymer to river embankment, it is necessary to examine the effects of biopolymers on a wide range of plant species in river embankment.

• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.105-114
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• 2017

Nowadays, novel and innovative technology including 3D printers, internet of things (IoT), and wearable devices are rapidly emerging. As we must constantly keep up with the most recent trends, words like convergence, multidisciplinarity, and design revolution indeed define society today. Due to the expansion of such diverse technological, industrial, and academic convergence trends, the role of design is becoming evermore essential in development of products as well as creative services. Even the government is pushing towards a 'creative economy' by encouraging ICT convergence to create novel industries as well as advanced jobs. In order to adapt flexibly to such changes in global trends, a solid academic curriculum centered around 'ICT+Design' must be developed. In the current research, we analyzed various literature and benchmarked the major universities both domestic and foreign. Also we utilized a survey-based approach against subjects who are experts or design specialists working in environments related to industry and research. In our proposed integrated ICT+Design educational curriculum, students familiarize themselves with design perspectives and methodology to creatively carry out the course. Moreover, experts from design and ICT came together in an act of 'Radical Collaboration' in which they shared their unique 'Design Thinking' in order to promote understanding and cooperation. Furthermore, industry experts have also taken part as mentors in order to create a workplace-oriented course with various integrated projects. Most importantly, the course was designed so that in addition to research, students can really get hands-on with their ideas in the creativity-integrated workplace.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.264-271
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• 2016

The purpose of this study was to investigate contamination sources of baby leafy vegetables by assessing microbial loads on baby leafy vegetables and agricultural inputs contacted with the vegetables. To estimate microbial loads, fecal indicators (coliform and Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) were examined. A total of 126 samples including eleven kinds of leafy vegetables, irrigation water, media, and tools were tested, resulting in coliform contamination observed from most of samples. For E. coli, 10.3% (13/126) of the samples were positive including irrigation water, knife, handler, media, tools, and three kinds of leafy vegetables. B. cereus was detected from 38% (48/126) of the samples including media, tools and three kinds of leafy vegetables. No E. coli O157:H7, Salmonella spp., and L. monocytogenes was detected. This result implies that contacting with agricultural inputs could explain microbial load of baby leafy vegetables.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.326-336
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• 2003

In order to modify the construction of gizzard shad coastal purse seine net with possible to the laborsaving of fishing operation in the coastal small fishing vessels, the model experiments were carried out on the model nets for several conventional nets using in the field and the experimental nets was manufactured as 1/100 and 1/60 of the full scale net. The results obtained are summarized as follows；1. In the case of the conventional net and reduction rate 75% in conventional net with purse line the fishing efficiency decreased, the lead line was upward for the surface and the pursing depth of pursing line was very shallow to 2∼3m. 2. In the case of the net having maximum depth in center part designed in this study, the length of float and lead line was 60% of conventional net, the depth of net was fixed 20m to selvage line of the both of the end and extend gradually with 50m, 40m, 30m to the center. Among the these net, depth of pursing line was 20∼23m for 50m and 7∼15m for 40m, 30m the depth of net. These results were suitable for interception of fish school in fishing ground, but several problems will be caused by the depth and current of fishing ground.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.604-609
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• 2008

Analyses were conducted to estimate carcass component of yield grade factors by sex and live weight class and to develop the prediction equation of retail product weight by sex in Korean native cattle (Hanwoo). Data from 42,113 Hanwoo carcasses were used to estimate the traits of yield grade factor and an additional 1,066 carcasses were used to develop the prediction equation of retail meat weight. The average of fasting weight of cow, bull and steer were 529 kg, 596 kg, and 634 kg respectively. Carcass weight (CW), backfat thickness (BFT), loineye area (REA), Index score of wholesale meat and yield grade were significantly (p<0.01) affected by sex and live weight. The lean meat percentage, fat percentage and bone percentage based on the weight of cold carcasses were significantly different (p<0.05) between sex groups. The equation of predicting the retail meat product from this study could be expressed as a multiple regression $Y=-4.18+0.63{\times}CW\;(kg)-0.17{\times}BFT\;(cm)+0.16{\times}REA\;(cm^2)$, $R^2=0.93$. Among the independent factors, the BFT was the highest contributor to the prediction equation. Using the equation from this study should allow for rapid, precise and cost-effective assessment of the retail product in Hanwoo beef carcasses.

• Journal of Gifted/Talented Education
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• v.18 no.2
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• pp.313-341
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• 2008

The research attempted to propose directions for improving evaluation of science gifted educational institutions affiliated with universities through its meta-evaluation. A survey questionnaire was developed and responded by 25 representatives of 25 science gifted educational institutions and 9 evaluation committee members in February 2008. According to research results, it was found that reference-criteria and categories for evaluation were abstract and did not reflect varied characteristics of individual institutions. Evaluation of outcomes mainly emphasized student number admitted by science high schools and science gifted school. Evaluation was performed for the sake of judging ranks. In addition, research capacity of institutions was not even considered as an evaluation element. For its improvement, the followings were suggested: First, evaluation should be functioned as consulting. Second, evaluation criteria are presented as concrete as it can be. Third, on-site evaluation should be introduced Fourth, evaluation process and results should be publicized Fifth, satisfaction by student and parents should be also included. Furthermore, exemplary cases of science gifted educational institutions should be identified and rewarded, and their management strategies should be disseminated with other institutions.