• Journal of Life Science
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• v.19 no.6
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• pp.809-817
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• 2009

The phenotypes associated with a gene function are often the best clue to its role in the plant. Transgenic plants ectopically expressing or suppressing a gene can provide useful information related to the gene function. In this study, we constructed three vectors - pFGL571, pFGL846 and pFGL847 - for the Agrobacterium-mediated ectopic expression of plant genes using pPZP211 and modified CaMV 35S, UBQ3 or UBQ10 promoters. The three vectors have several merits such as small size, high copy in bacteria, enough restriction enzyme sites in multi cloning sites and nucleotide sequence information. Analysis of transgenic plants containing GUS or sGFP reporter genes under the control of modified CaMV 35S, UBQ3 or UBQI0 promoter revealed that all of the three promoters showed high activities during most developmental stages after germination and in floral organs. Furthermore, we generated a RNAi module vector, pFGL727, to suppress plant gene expressions and confirmed that pFGL727 is useful for the suppression of a gene expression using rice transgenic plants. Taken together, our new vectors would be very useful for the ectopic expression or the suppression of plant genes.

• Korean Journal of Environment and Ecology
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• v.22 no.1
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• pp.43-58
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• 2008

For this study, which was conducted in the summer from $2004\sim2007$, 10 small and medium sized streams in Korea were selected(Munsan and Gokreung Stream in the Han River watershed, Mi, Ssanggye and Nam Stream in the Nakdong River watershed, Gapeong and Jojong Stream in the Bukhan River watershed, Cheongmi, Yanghwa and Bokha Stream in the Namhan River watershed), and plant surveys were performed using the belt transect method on the most natural 1km sections of each stream in order to clarify the natural environment condition of the plants in each stream. In the results of the plant survey, the total number of plant species recorded was 296. After selecting 121 species of those surveyed plant in order of frequency, an RDA(Redundancy Analysis) and a Pearson Correlation Analysis were performed to determine the correlation between the selected plant species and environmental factors( such as distance from channel, size of bed material, number of bars, altitude, bed slope, width of channel, and measured data of water quality) of the study sites. There was no significant correlation between the 121 plant species and altitude, bed slope, and number of bars at the research sites, but the correlation of plant species with size of bed material, width of channel, electrical conductivity, and phosphate$(PO_4-P)$ concentration was from very high to moderate. Also, the spectrum of these plant species reflects the actual environmental conditions so the method used in the study seems to be correct, but owing to the range of diversity, the results of the study seem to be difficult to extend to other streams. Nevertheless, it is expected that this data can be used as a basic material for researching plants by stream characteristics or in selecting plant species for streams.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.131-137
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• 2018

The two recent excavations at the site of Beopsusa Temple in Seongju revealed that it contained eight building remains, three pedestrian facilities, four drainage facilities, two walls, three embankments, and an estimated pagoda remain. Even though this investigation was restricted to some sections of the site, it confirmed remains of architectural significance and thus attracted the attention of concerned researchers. This study thus set out to make an architectural survey of the site based on the excavation results and examine the characteristics and nature of remains of Buildings No.2 and 3 at the site. The planar analysis results show that Building No.2 (Remains 2-2) at the site of Beopsusa Temple was a gable-roofed building with a single story including 6 kan(間) in the front and 4 kan(間) in the flank and that Building No.3 (Remains 3-3) was a single-story building with a hipped-and-gable roof including 5 kan(間) in the front and 3 kan(間) in the flank. The most noteworthy remain of this excavation was the north-south square platform discovered at the Building No.2 at the site. It is estimated as a high chair platform used for Buddhist sermons. It was confirmed only at the lecture hall remains of Hwangnyongsa Temple and Anyangsa Temple in the nation and had never been found at remains related to Chinese and Japanese Buddhist Temples, being regarded as a very important and unique artifact. Since it was found at the remains of Building No.2, they was estimated as the lecture hall remain at the site. Found at the remains of Building No.3 at the site, the oblong altar remains were also very unique and rare and never found at other Buddhist temple sites. The inside of oblong altar was evenly covered with roof tiles instead of rubble, and there were small crushed stones for internal division, which is an altar construction method distinctly different from its counterparts at other Buddhist temple sites. Those findings raise the possibility high that a wooden facility was put up at the top of oblong remains.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.74-83
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• 2021

Distribution status, habitat characteristics, and extinction threat evaluation of the endangered species, Brachymystax lenok tsinlingensis were investigated in 2015 and 2019. Historical distribution reports of B. l. tsinlingensis were divided into before 1990, 1997~2006, 2000~2011, and 2010~2019. Among the 150 sampling sites investigated during the study period, number of individuals of B. l. tsinlingensis were collected 542 individuals from 67 sites. The streams inhabited of B. l. tsinlingensis were Naerincheon (11 stations), Odaecheon (11 stations), Bukcheon (10 stations), Bangtaecheon (8 stations), Songjeongricheon (4 stations), Suipcheon (3 stations), Inbukcheon (3 stations), Hyeondongcheon (3 stations) etc. The main habitat of B. l. tsinlingensis was upstream of the river with a high altitude of more than 400 m, 4~20 m water flow width, 1~2 m water depth, and high ratio (70~80%) boulder bottoms. The main reasons for the decline in population size were assumed as river works, construction of reservoirs and bridges, discharge of contaminated water into the river, the inflow of summer vacationers, and weir. Compared to our results there exists evidence that states a 20.7% reduction in occupancy within 10 years, in a small appearance range (7,732 km²) and occupancy area (268 km²), number of disconnected locations (15 locations), and a decline in habitat quality. Therefore, B. l. tsinlingensis is now considered as Near Threatened (NT) based on the results (Near meets VU A2acd, B1b(i,ii,iii)+B2b(i,ii,iii)) of IUCN Red List categories and criteria.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.34-43
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• 2022

A distribution survey was conducted from March to August 2021 to evaluate the distribution status, habitat characteristics, and threat of extinction of the Korean cold-water fish Ladislabia taczanowskii Dybowski (Cypriniformes, Cyprinidae). Historical distribution reports were divided into 1997~2005, 2006~2012, 2013~2019, and distribution surveyed 169 sampling sites, and 1,040 individuals were collected from 72 sites. Areas where the habitat was confirmed were Namhan River (27 stations), Han River (17 stations), Bukhan River (16 stations), Samcheok Osipcheon (4 stations), Yeongokcheon (3 stations), Gangneung Namdaecheon (2 stations), Jeoncheon (1 station), Chucheon (2 stations). The main habitat of L. taczanowskii was upstream of the river with a high altitude of more than 300 m, 2~30 m water flow width, 0.3~1.5 m water depth, and high ratio (50~90%) boulder bottoms. The main reasons for the decline in population size were assumed as river works, construction of reservoirs and bridges, discharge of contaminated water into the river, the inflow of summer vacationers, and weir. Compared to our results there exists evidence that states a 36.1% reduction in occupancy within 10 years, in a small appearance range (7,820 km²) and occupancy area (288 km²), number of disconnected locations (19 locations), and a decline in habitat quality. Therefore, L. taczanowskii is now considered as Vulnerable (VU) based on the results (VU A2ac, Near meets B1b (i, ii, iii)+B2b (i, ii, iii)) of IUCN Red List categories and criteria. Lastly, the conservation plan of Ladislabia taczanowskii was discussed.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.385-393
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• 2007

Benthic macroinvertebrate communities were studied after a small dam removal from the mid-section of the Gyeongan stream in Gyeonggi-do, Korea. Quantitative sampling was conducted at immediately upstream (upper) and downstream (lower) sites from the dam as well as at the site where the dam was located (dam site: middle) using a Surber sampler (50$\times$50 cm, mesh 0.25 mm), four times (November 2004, May 2005, January 2006, and May 2006) after the dam removal. As a result, 46 species of benthic macroinvertebtates, belonged in 35 genera, 27 families, 11 orders, 5 classes, and 4 phyla, were sampled from the stream sites, but the number of species that occurred at each sampling trial was different (ranged 3$\sim$17 spp.) according to the seasons and sites. Approximately one year after the dam removal, the species number has in-creased and taxa composition has changed as the microhabitat became more heterogeneously due to a riffle formation in the upstream site. Chironomid larvae and tubificid worms, which are common in Korean urban streams, were the dominant species, while Hydropsyche kozhantschikovi was the 2nd dominant species at some sampling trials. In general, McNaughton's dominance indices decreased and Shannon species diversity indices increased approximately one year after the dam removal. Compositions of collector-filterers, clingers, and swimmers increased as hydropsychid caddisflies, heptageniid mayflies, and baetid mayflies increased, respectively, in the upstream site. The group pollution index and the ecological score using benthic macroinvertebrates both indicated that water environment has been improved in the upstream site after the dam removal.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.543-560
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• 2018

With the increased development in downtown underground space facilities that vertically cross under a railway at a shallow depth, the demand for non-open cut method is increasing. However, most construction sites still adopt the pipe roof method, where medium and large diameter steel pipes are pressed in to form a roof, enabling excavation of the inside space. Among the many factors that influence the loosening region and loads that occur while pressing in steel pipes, the size of the pipe has the largest impact, and this factor may correspond to the magnitude of load applied to the underground structure inside the steel pipe roof. The super equilibrium method (SEM) has been developed to minimize ground disturbance and loosening load, and uses small diameter pipes of approximately 114 mm instead of conventional medium and large diameter pipes. This small diameter steel pipe is called an SEM pile. After SEM piles are pressed in and the grouting reinforcement is constructed, a crossing structure is pressed in by using a hydraulic jack without ground subsidence or heaving. The SEM pile, which plays the role of timbering, is a fore-poling pile of approximately 5 m length that prevents ground collapse and supports surface load during excavation of toe part. The loosening region should be adequately calculated to estimate the spacing and construction length of the piles and stiffness of members. In this paper, we conducted a comparative analysis of calculations of loosening load that occurs during the press-in of SEM pile to obtain an optimal design of SEM. We analyzed the influence of factors in main theoretical and empirical formulas applied for calculating loosening regions, and carried out FEM analysis to see an appropriate loosening load to the SEM pile. In order to estimate the soil loosening caused by actual SEM-pile indentation and excavation, a steel pipe indentation reduction model test was conducted. Soil subsidence and soil loosening were investigated quantitatively according to soil/steel pipe (H/D).

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.485-500
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• 2020

Due to various advantages such as small facilities, ease of construction and so on, the grouting technology which is widely used in construction field has developed remarkably compared with the past. However, the efforts to improve the homogeneity of quality, long-term durability and environmental problems have been continued. In recent years, new grouting method has been developed in order to solve problems such as low strength, durability and leaching phenomenon of liquid glass (sodium silicate) grouting material in Korea. A newly developed method integrates the injection material with the ground by the self-healing material of crystallization growth type. For this reason, it is known that improvement of the durability and water quality of the ground, prevention of leaching, and environment friendliness can be expected. The present study applied a newly developed method to test sites and verified its effect such as injection range, improvement effect, waterproofing performance and so on. Standard penetration test, field permeability test, borehole shear test, pressuremeter test and pH test were conducted, and the results were compared between before and after developed method application. As results of tests, the field applicability and improvement effect of developed method were proved to be excellent.

• Fire Science and Engineering
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• v.34 no.3
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• pp.141-149
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• 2020

The Korea Industrial Standards (KS) stipulates methods and test procedures for measuring the horizontal combustibility of cellular plastics exposed to small flames (KS M ISO 9772:2018) and recommendations regarding the magnetic digestion of extruded polystyrene insulation (XPS) for measurement results (KS M 3808:2020). Although products that are certified to conform to KS standards must have burning characteristics (self-extinguishing), they are incinerated and spread by welds at construction sites, causing significant human and property damages. In this study, XPS produced by five companies, certified by KS, and sold in the market were purchased and tested for ignition and diffusion caused by a weld bullion at a construction site. The results showed that the five products had differences in performance. Three out of the five products were found to be self-saturated, but the other two were easily ignited and diffused, making it difficult for them to be self-extinguishing. Based on the result of this experimental investigation in line with the KS regulations, all the three types of products, including two types of products that were incinerated through weld defects, were found to be non-self-extinguishing, as specified in KS M 3808.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.111-120
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• 2016

The objective of this study was to provide basic information for selecting the right timing and the right place of erosion control of stream on Gyeongsangnam-do. In order to achieve this objective, a total of 526 erosion control dams and 230 mountains stream conservation facilities on the constructed places and construction planned places for the erosion control were investigated on site, forest physiognomy, and hydrologic conditions. The erosion control dams and mountain stream conservation facilities were mostly constructed in the area, which has the sedimentary rock, 200-400m of altitude, a slope of 21~30°, and II of landslide hazard map. Among the forest environmental factors, it was only similar to the construction frequency in the areas that have small diameter class, III age class. Also, we investigated the hydrological environmental factors that determine the size and numbers of erosion control dam. The places constructed to the highest frequency were below 50ha in the area, 2.1~4.0km/㎢ of drainage density, longitudinal water system, 61~90mm of maximum precipitation per hour, and 201~300mm of day maximum precipitation. As the results, the sites and floodgate conditions between the constructed places and stream conservation facilities for the erosion control showed to be very similar. Therefore, these results indicate that the erosion control of the stream of the areas, which have the disruption of mountain peaks and the high erosion risk areas, should be used on both the erosion control dam and stream conservation facilities.