• Journal of The Korean Association For Science Education
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• v.40 no.2
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• pp.127-140
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• 2020

This study investigated the influence of an explicit and reflective modeling instruction on the metamodeling knowledge of fourth-graders. Two fourth-grade classes in an elementary school in Seoul were selected and each class was assigned to an experimental group and a control group, respectively. The experimental group was engaged in explicit and reflective modeling instruction, whereas the control group was engaged in implicit modeling instruction. The two groups were surveyed before and after instruction on the basis of five metamodeling knowledge categories: definition, purpose, design/construction, changeability, and multiplicity. The experimental group showed positive changes in model's meaning, examples, purpose, changeability as well as multiplicity. In contrast, fewer students in the control group understood the meaning of the model and modeling. They also showed limited changes in their understandings with regards to the modeling instruction, and could not expand their understanding of the nature of model and modeling. The findings indicate that an explicit and reflective modeling instruction has positive influence on elementary students' metamodeling knowledge.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.91-108
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• 1998

This study was carried out to survey basic information of swine farms on the machine holdings. facility type. management of manure by farm scale and operation, and then to develop the mechanization model. Manual feeding was common for sows and nursing sows. but automation feeding was normally furnished for weaners. growing pigs and castrated male pigs. Water supplies was completely automated for all of the surveyed swine farms. Fully mechanized and automated system would not be feasible and affordable for the small scale farms breeding less than 500 heads. Because the environmental control for the nursing sows and weaner was important, some swine houses were constructed with the windowless type. However, the furnished rates ranged from 22.2% to 44.4% of the surveyed nursing sow and weaner houses at the farm scales. In the future, a computerized ventilation system would be commended for the efficient use of heat energy and to maintain the desirable temperature of swine buildings. Over-investment for large scale farm and over-crowded pigpen of small farm would cause wasting construction expenses and spreading epidermic diseases Hence, the size of swine building should follow the recommended scale. The fermentation drier was recommended for the manure management. Urine could be recycled or discharged after treating by the activated sludge process.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1223-1229
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• 2009

To construct a new recombinant strain of Bacillus velezensis that has antifungal and insecticidal activity via the expression of the insecticidal Bacillus thuringiensis crystal protein, a B. thuringiensis expression vector (pHT1K-1Ac) was generated that contained the B. thuringiensis cry1Ac gene under the control of its endogenous promoter in a minimal E. coli-B. thuringiensis shuttle vector (pHT1K). This vector was introduced into a B. velezensis isolate that showed high antifungal activities against several plant diseases, including rice blast (Magnaporthe grisea), rice sheath blight (Rhizotonia solani), tomato gray mold (Botrytis cinerea), tomato late blight (Phytophthora infestans), and wheat leaf rust (Puccinia recondita), by electroporation. The recombinant B. velezensis strain was confirmed by PCR using cry1Ac-specific primers. Additionally, the recombinant strain produced a protein approximately 130 kDa in size and parasporal inclusion bodies similar to B. thuringiensis. The in vivo antifungal activity assay demonstrated that the activity of the recombinant B. velezensis strain was maintained at the same level as that of wild-type B. velezensis. Furthermore, it exhibited high insecticidal activity against a lepidopteran pest, Plutella xylostella, although its activity was lower than that of a recombinant B. thuringiensis strain, whereas wild-type B. velezensis strain did not show any insecticidal activity. These results suggest that this recombinant B. velezensis strain can be used to control harmful insect pests and fungal diseases simultaneously in one crop.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.527-534
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• 2011

This paper describes an analysis of topographical changes to the Eulsuk-Island at the Nakdong River Estuary using a long-term dataset of high resolution aerial images from 1983 to 2007. Ground control surveying was performed at some feature points using GPS(Global Positioning System) to accomplish AT(Aerial Triangulation) for past aerial images. Even if some still existing feature points appeared on old aerial images were used as GCPs(Ground Control Points) for past aerial images in AT, its accuracy reached at 1m level. Since then, a quantitative analysis of topographical changes was conducted on digital orthophotos produced by a series of aerial images taken by different years. The change volume of total area, construction, vegetation, buildings and roads could be extracted per each period in study area. The total area decreased from 1983 to 1992, but it has not almost changed since 1992. According to the continuous development, the area of vegetation has steadily decreased, while that of buildings and roads has generally increased. The result of this study can provide us with invaluable base data for further topographical change monitoring in Eulsuk-Island and Nakdong River estuary caused by continuous development in this area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.167-175
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• 2018

To cope with the increasing number of natural disasters in recent years, managers in the National Disaster and Safety Status Control Center, who have considerable experience and skills, are regarded highly important. Although the National Disaster and Safety Status Control Center oversees the disaster-status control tasks in preparation for various natural and social disasters, there is little data due to the frequent replacement of managers. Therefore, this study developed a disaster-safety code system that tracks and manages disaster information, because the current record management and amount of information sharing remains very low. Among 22 natural and social disaster types, this study targeted four types of disasters: heavy snow, strong winds, high seas, and heavy rain. The final disaster-safety data code system was proposed through the following processes: analysis of the code systems of disaster areas in Korea and overseas, setup of the implementation of directions, development of the classification system, and categorization. For the systematic accumulation of data, the four code systems were integrated into one. A prototype system was developed and operated to verify the validity of the proposed code system. The results showed that data were accumulated and services were provided accordingly with respect to the proposed code system. If past data are accumulated and utilized according to the proposed code system in this study, it will be helpful in the decision making process to respond to new types of disasters, based on past experiences.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.849-860
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• 2019

This paper is a study on the development of equipment system to obtain data on stability in excavation of sharp curve section of Shield TBM. Shield TBM equipment is being used a lot recently for tunnel excavation. Excavation may result in inevitable detours by buildings above the ground or existing underground structures. Preconstruction simulation is required to verify the stability of the construction in case of this. Therefore, it is necessary to establish an automated control system through the development of this equipment system and conduct simulation through simulation of excavation model in the sharp curve section. A system shall be developed to control the left and right angles and thrust of the equipment, and to view data on the earth pressure and propulsion pressure of the equipment in real time during excavation. With this system, the necessary data can be collected for field testing through excavation method and excavation simulation by angle. It is expected that it will be very useful in assessing the actual Shield TBM by conducting a scale-down model experiment.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1145-1151
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• 2010

The objective of this work was to analyze the relationship between ovine major histocompatibility complex (MHC) DRB1 gene polymorphism and genetic resistance to hydatidosis in Kazakh sheep. The Ovar (ovine MHC) class II DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of 702 Kazakh sheep, including 302 sheep with hydatidosis and 400 health controls. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique using five restriction enzymes, i.e., MvaI, HaeIII, SacI, SacII and Hin1I, yielding 14 alleles and 28 genotypes. Comparing the frequency of genotypes in hydatidosis sheep with the control group, it was found that the genotype frequencies of MvaIbc, Hin1Iab, SacIIab, HaeIIIde, HaeIIIdf and HaeIIIdd in control sheep were significantly (p<0.01) higher than in hydatidosis sheep, indicating that a significant correlation existed between these genotypes and resistance to hydatidosis. Genotype frequencies of MvaIbb, SacIIaa, Hin1Ibb and HaeIIIef in sheep with hydatidosis were extremely significantly (p<0.01) higher than in the control group, and the genotype frequency of HaeIIIab was significantly higher (p<0.05), indicating that a marked correlation existed between these genotypes and susceptibility to hydatidosis. By way of analyzing haplotype with these resistant genotypes, the hydatidosis resistant haplotype MvaIbc-SacIIab-Hin1Iab of Kazakh sheep was screened out, and then verified through artificial hydatid infection in sheep. The results indicated that the infection rate of sheep with the resistant haplotype of hydatidosis was significantly lower (p<0.01) than without this resistant haplotype. It showed that the genic haplotype MvaIbc-SacIIab-Hin1Iab of Ovar-DRB1 exon 2 was the resistant haplotype of hydatidosis in Kazakh sheep.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.323-329
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• 2005

In this paper, performance of a hybrid sequential aerobic-anaerobic natural system was investigated. Continuous aerobic and anoxic conditions were created by alternatively placing waste stabilization pond (WSP) and wale. hyacinth pond (WHP). Two pilot-scale treatment lines were built and operated; The first consists of WSP integrated with WHP and the second of WSP connected with Dark Pond(DP), namely control system ponds which were used to examine the effects of water hyacinth on nitrification and de-nitrification. The overall performance in nitrogen was 86% reduction in WSP-WHP and 36% in WSP-control pond system. Nitrogen was mostly removed by nitrification and de-nitrification which simultaneously occurred in the same water hyacinth ponds. For the de-nitrification, benthic layer was found out to be adequate support as a carbon source. In addition, WSP-WHP system was very effective in reducing phosphorus. Overall P removal efficiency in WSP-WHP is 81%, while it is only 16% in WSP-control. difference in phosphorus reduction between those two systems is thought to be caused by the plants and probably their roots producing extra-cellular materials, but these aspects need to be further studied.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.120-140
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• 2016

The purpose of this study is to assess the green space considering functional characteristics in order to provide the base data for efficient green planning and management. The study area was the park-type green spaces in Daegu and the functions were limited in nature-ecological, environment-control, and usage functions. Thirteen indicators were selected from the literature review and MCB analysis of expert survey. The weightings of functional indicators were established through AHP analysis of expert survey. According to the results of functional assessment, Naengcheon amusement, Deagu sports, and Dalchang amusement parks had scores of more than 80 in the case of nature-ecological function. Fifteen parks such as Bokhyeon, Manchon, and Cheonnae parks had scores of more than 75 in terms of environment-control function and eleven parks such as Suseong, Dalseong, and Wolbae parks had scores of more than 80 in usage function. The findings from this study can be used as the base data and guideline for construction of new park-type green space and continuous management and remodeling of current green space.

• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.277-285
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• 2014

The purpose of this study is to investigate experimentally the variation factors range having influence on the rheological properties of the combined self-compacting concrete according to materials quality, weighting error and site conditions. Two types cement (blast-furnace slag cement and belite cement), lime stone powder as binder and the optimum mix proportions in the preceded study are selected for this study. Also, variations for sensitivity test are as followings; (1) Concrete temperature 3 cases (2) Surface moisture of sand 5cases (3) Fineness modulus of sand 5cases (4) Specific surface of lime stone powder 3cases (5) Dosage of chemical admixture 5cases. Slump flow ($650{\pm}50mm$), 500 mm reaching time (($7{\pm}3sec$), V-type flowing time ($15{\pm}5sec$) and U-box height (min. 300 mm) are tested for sensitivity. As test results, the variations range for quality control are as followings. (1) Concrete temperature; $10{\sim}20^{\circ}C$(below $30^{\circ}C$) (2) Surface moisture of sand; $base{\pm}0.6%$ (3) Fineness modulus of sand; $2.6{\pm}0.2$ (4) Dosage of chemical admixture; $base{\pm}0.2%$ (5) Specific surface of lime stone powder $6000cm^2/g$. Compared with two types cement including based belite cement (binary type) and based slag cement (ternary type), the combined self-compacting concrete used belite cement type is most stable in the quality control because of high contents for lime stone powder and $C_2S$. It is to propose a control scheme of the combined self-compacting concrete in the actual construction work.