• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.149-157
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• 2019

This study interested on management of broodstock and the effect of raise the temperature for promotion of maturity in Tresus keenae. For management of broodstock, we performed indoor and outdoor culture. In addition, broodstock was put in exposure and immersion condition. This experimental design is aimed at knowing the optimal management of broodstock. In addition, we investigated the promotion of maturity, growth and survival rate when raise the temperature of the breeding seawater of broodstock in winter season. Result that, the management of broodstock was shown to be more effective obesity and survival rate in outdoor culture than indoor culture. In addition, there is no anthropogenic food supply in management and it is easy to management because it is kept under natural environmental conditions. Therefore, It is considered appropriate to management to outdoor culture. In raise the temperature, survival rate was lower in the experimental group than in the control group. However, obesity was significantly increased compared with the control group. Also, gonad showed that the sex maturity was promoted. If sex maturation is not developed due to seasonal water temperature, the promotion of sexual maturity through heating is considered to be an effective method in terms of artificial seed production.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.195-207
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• 2002

The domestic, quantity of copper slag as a by-product at copper smelting process reaches 700,000 tons annually while its application is limited. Therefore, the secure disposal plan of copper slag is urgently required. For this reason, in this study, copper slag was used as a substitute for sand in Sand Compaction Pile that is one of the improvement methods of soft ground because the particle size distribution of copper slag ranges from 0.15mm to 5m(coarse state) and it maintains stable glassy state environmentally. The geotechnical characteristics of copper slag were evaluated through laboratory model tests and the field application of copper slag was compared with generally used sand by pilot tests. From these experimental results, copper slag's material characteristics, bearing capacity, settlement reduction and improvement effects of surrounding ground were found to be superior to generally used sand. The copper slag can be used as a substitute far sand in the Sand Compaction Pile method and as recycling material of industrial by-product with high econonical and environmental value when natural resources are being exhausted.

• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.57-65
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• 2019

In this study, to investigate the effect of cylindrical countermeasure on the flow characteristics of debris flow, a series of small-scale tests were conducted using a flume with cylindrical baffles. Various heights and row numbers of installed baffles were considered as a test condition. High speed cameras and laser level sensors were also installed at the top and side of the channel, respectively, to capture the debris flow dynamics before and after baffles. Based on test results, the energy dissipation of debris flow due to baffles was analyzed. Test results showed that baffles can significantly reduce the velocity and flow depth of debris flows. The energy dissipation effect of baffles also increase as the increase of height and row number of baffles.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.35-42
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• 2014

It is possible to improve the obstacle avoidance capability by training and recognizing the obstacles which is in certain indoor environment. We propose the technique that use underlying intensity value along with intensity map from RGB-D image which is derived from stereo vision Kinect sensor and recognize an obstacle within constant distance. We test and experiment the accuracy and execution time of the pattern recognition algorithms like PCA, ICA, LDA, SVM to show the recognition possibility of it. From the comparison experiment between RGB-D data and intensity data, RGB-D data got 4.2% better accuracy rate than intensity data but intensity data got 29% and 31% faster than RGB-D in terms of training time and intensity data got 70% and 33% faster than RGB-D in terms of testing time for LDA and SVM, respectively. So, LDA, SVM have good accuracy and better training/testing time to use for obstacle avoidance based on intensity dataset of mobile robot.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.31-45
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• 2009

The aim of this study is to evaluate the applicability of Granulated Blast Furnace Slag to the development of the Powdered Ready-mixed Shotcrete. First of all, after accomplishing SEM analysis and Leaching Test, the laboratory and field experiments for evaluating the utility of Granulated Blast Furnace Slag were performed. As a result of SEM and Leaching test, the environmental stability was confirmed. That is, non-detection of harmful lists and dense shotcrete structure result from mixing Granulated Blast Furnace Slag. As a result of lab. and field test, Blast Furnace Slag is superior to Plain Batch in improving strength and durability. And it will be able to improve to some extent the problem caused by the delayed reaction of existing Granulated Blast Furnace Slag with alkali activated material. Also the proper amount of Granulated Blast Furnace Slag is estimated to be under 30%. Finally, it is possible that Granulated Blast Furnace Slag can apply to economical recycling and development of the Ready-mixed Shotcrete for its price is only about 5% of Silica-finne's price.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.19-26
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• 2009

Rammed Aggregate Pier (RAP) method is intermediate foundation between deep and shallow foundation, and it has been built in world wide. RAP represents a relatively new method that has grown steadily over 19 years since Geopier of USA developed this revolutionary method in 1989. The investigation and research in domestic is not accomplished. In this paper, the examined details of different spacing of piles, bearing capacities, respectively, conclude with recommendations on how RAP can be used in future needs. This documentation further provides comparisons of the laboratory test results which were obtained from changing the spacing of piles, namely installed rammed aggregate pier. Laboratory model test was administered in a sand box. Strain control test was conducted to determine the bearing capacities of the piers; 20 mm, 30 mm and 40 mm RAP in diameter using drilling equipment to make holes were installed in sand at initial relative densities of 40%. By comparing different spacing of piles, in this experiment, piles are spaced structually span, form a ring shape, narrowing the distance of each other, to the center. the result shows that as diameter of pier is bigger in diameter, bearing capacity also dramatically increased due to raised stiffness. Also, as the space between each piers was closed, the settlement rate of soil was decreased significantly. From the test results, as the space between each piles were getting closer, it allows greater chances to have more resistance to deformation, and shows more improved stability of structures. After from the verification work which is continuous leads the accumulation of the site measuring data which is various, and bearing capacity and the settlement is a plan where the research will be advanced for optimum installed RAP.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.163-170
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• 2020

This research was to understand the current situation and trends of urban design using rapidly growing solar cells at home and abroad, and to understand the positive aspects and implications of urban design proposals using CIGS thin film solar cells, a research project to be conducted based on case analysis. The research method was conducted through a literature study and the case was investigated and analyzed after identifying the present situation and trends of urban design using solar cells from home and abroad. As a result, it was confirmed that urban design using solar cells was steadily increasing, and through visual changes such as harmony with the surrounding environment, indoor and outdoor visualization, and the use of color, urban aesthetic beauty creation was positive. Based on these implications, we will present the expected effects of CIGS thin film solar cells being utilized in urban design, and confirm the direction and significance of the urban design proposal using CIGS thin film solar cells in the future.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.51-63
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• 2011

Surface of fine-size exposed aggregate portland cement concrete pavements(FS-EAPCC) is consist by exposed coarse aggregate to remove upper 2~3mm mortar of concrete slabs. Advantages of FS-EAPCC are maintaining low-noise and adequate skid-resistance level during the performance period. However, FS-EAPCC is required rational management criteria for field application, since it is early stage for application. Design construction and quality control criteria of FS-EAPCC was temporary laboratory tests which including optimum mix and exposing method, selection of adequate aggregate, resistance against, environmental loading and etc. However, these criteria need to be validated base on field application. In this study, experimental constructions were performed and construction procedure and quality control criteria were suggested based on the performance of the FS-EAPCC.

• International Journal of Highway Engineering
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• v.4 no.1 s.11
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• pp.135-147
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• 2002

Application of the foamed asphalt techniques in recycling the waste asphalt shows that large quantify of waste asphalt(60$\sim$70% of the total mix) can be used comparing with hot mix asphalt techniques and also is environmentally safe. However, the constant quality of the recycling foamed asphalt mixtures is not readily achieved and can not be applied to the heavy traffic road due to the characteristics of the conventional foamed asphalt mixtures. The semi-hot technique that the RAP and the aggregate is heated below $100^{\circ}C$ is adopted in this study and expected to solve the problems of conventional foamed asphalt mixtures. This study presents the viability of the semi-hot foamed asphalt mixtures when using the RAP. The semi-hot recycling foamed mixtures are tested and evaluated in the laboratory. The test results including coating rates, creep tests, resilient modulus tests, indirect tensile tests and the Marshall stability tests showed significant improvement.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.45-54
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• 2016

In this study, the construction method of new underground continuos impervious wall that the bentonite slurry keeps the stability of excavated trench and the mixture of cement and bentonite plays a role as a constituent of impervious wall in the trench. The merit of homogeneity of the method so called as a cement-bentonite slurry wall enables to accurately make an estimation of hydraulic conductivity of the walls compared with that by other general grouting methods and to verify their waterproof efficiency without difficulty at the design stage. The use of cement-bentonite slurry walls for the containment of groundwater flow has also proven a cost-effective impervious wall technology by employing the simple combination of construction equipments and easy and fast construction procedures. The engineering characteristics of cement-bentonite impervious wall obtained by carrying out the laboratory experiments under various conditions. This study reveals the effect of variation of constituent materials and their mixing methods (Water-Cement-Bentonite) on the engineering characteristics of a composition. Also, this study makes some recommendations on the optimum mixing ratio and mixing sequence for the best quality at the site. That is the most important factors to estimate the construction cost and design of the technique. The comparison is lastly made to evaluate the effect of ordinary Portland and blast furnace slag cement as a bonding material on the behavior of impervious walls.