• International Journal of Highway Engineering
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• v.5 no.3 s.17
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• pp.31-42
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• 2003

The KHC Test Road project was initiated on 1991 to develop Korean Pavement Design Guide. It was constructed along the Joongbu Inland Expressway line between Yeoju and Gamgok. It is two-lane wide expressway containing fifteen asphalt and twenty-five Portland cement concrete test pavement sections. Various sensors were installed in the Test Road to evaluate the behavior of test pavement sections under the influence of traffic load and environmental change. The most important issues in the sensor installation are the accurate location and long-term survivability. They are directly influenced by the sensor installation methodology. The methodology for asphalt strain gages is mainly discussed in this paper because it is the second important sensors in the KHC Test Road project. In order to find the best methodology, we evaluated existing methodology from prior experience and several conducted test installations. We have tried mound, block out, and trench cuts since 2000. Among three methods, block out was the most effective one in terms of accurate location, long-term survivability, and material homogeneity. However, this method cannot be applied to the wearing coarse so that the mound method was used as an alternative. The block out method was applied to base and intermediate layers while the mound method was used to the wearing coarse. Three hundred seventy-four asphalt strain gauges were installed on asphalt pavement sections from September 3rd to November 18th in 2002. According to the sensor measurement evaluation, 6.3% of sensor demonstrated over ranged readings for mound method installation and 2.5% did for block out method installation. We lost only two sensors during the installation. It is 99.5% survival and it is excellent survival rate according to other experience.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.243-252
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• 2008

The Iho and Hamdeok beaches, the major coastal beaches in Jeju Island, have been studied through size analysis and using an experimental extension pole and sediment trap in beach profile, in order to understand their textural characteristics, migration patterns, and seasonal change in beach geometry. The Iho beach is composed of coarse and medium sands, 590 m in total length. The foreshore slope is 12.3$^{\circ}$ in summer and 10.8$^{\circ}$ in winter, which shows more steeper in summer. The Hamdeok beach consisting mostly of shell fragments is 950 m long, $5.7{\sim}7.4^{\circ}$ steep and 97.4${\sim}$114.5 m wide, respectively. The suspended load drift concentrations in the studied beaches showed 4.5 mg/l during the period of summer and 33.2 mg/l in winter, and those of fine-grained sediments are derived mostly from the marine of northeastward direction. The typical beach transformation of the Iho beach is resulting from the construction of jetties in the west side that built up the sand inside the jetties, whereas the erosion is occurring on the east side of beach. The center and berm sides of the sand in the Hamdeok beach drift into the dune side during the period of the stormy winter season.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8455-8461
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• 2015

In this paper, we propose new search algorithms using SVD(Singular Value Decomposition) for fast search of Raman spectrum. In the proposed algorithms, small number of the eigen vectors obtained by SVD are chosen in accordance with their respective significance to achieve computation reduction. By introducing pilot test, we exclude large number of data from search and then, we apply partial distance search(PDS) for further computation reduction. We prepared 14,032 kinds of chemical Raman spectrum as the library for comparisons. Experiments were carried out with 7 methods, that is Full Search, PDS, 1DMPS modified MPS for applying to 1-dimensional space data with PDS(1DMPS+PDS), 1DMPS with PDS by using descending sorted variance of data(1DMPS Sort with Variance+PDS), 250-dimensional components of the SVD with PDS(250SVD+PDS) and proposed algorithms, PSP and PSSP. For exact comparison of computations, we compared the number of multiplications and additions required for each method. According to the experiments, PSSP algorithm shows 64.8% computation reduction when compared with 250SVD+PDS while PSP shows 157% computation reduction.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.952-957
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• 2005

A sensitivity analysis study was performed to examine the effects of cell size on a distributed non-point source pollution model. The model, AnnAGNPS, whiff is a modified version of USDA's AGNPS, was applied to Eung stream watershed, a tributary of Cheongmi stream located in the South Branch of Han River System. The model components and results, such as channel length, slope, land use, and delivery ratio, were analyzed according to the various cell sizes from 10 to 200 ha. As cell sire increases, channel length decreases due to short-circuiting of meandering creek. The decreased channel length has more significant effects on the model results than any other geomorphological change. When the effects of land use and soil distribution are excluded, sediment delivery loads increase due to shorter time to reach the outlet of the watershed in larger tell size. When those effects are included, however, sediment delivery loads decrease in larger fell size because the variety of land use types can not be inputted. The predominant land use in the applied watershed is forest with very low soil erosion such that the predicted sediment delivery might be much lower than real system. The cell size of 30 ha was determined to produce the most appropriate resolution. Surface runoff and non-point source loads of TN, TP and BOD were predicted and the results agree well with the field measurements. From this study, it was shown that the model results would be very dependent on variations of topography, land use, and soil distribution, as a function of cell size, and the optimum cell size is very important for successful application of distributed non-point source pollution model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.487-493
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• 2017

The main purpose of this study is to evaluate the main parameters involved in the asphalt pavement distresses, including IRI (International Rough Index), fatigue, and permanent deformation. The main parameters are the region (Seoul and Busan), traffic level, asphalt binder, maximum aggregate of surface course, thickness of the surface course and base. A total of 64 case studies were carried out under the auspices of the KPRP (Korea Pavement Research Program). From the analysis of the KPRP test results, the key factors for the asphalt pavement distress were determined. Considering the effect of one variable in the basic condition, asphalt binder was the major factor having an effect on the distresses for an AADT (Annual Average Daily Traffic) of 5000 in the Seoul area. Among the remaining factors, the results were found to be in the order of the base layer thickness (A), surface layer thickness (B), and aggregate particle size thickness (D). The same results were obtained for an AADT of 10000. In the case of Busan with an AADT of 5000, the same result was obtained as for Seoul. Among the remaining factors, the results were in the order of the base layer thickness (A), aggregate particle thickness (D), and surface layer thickness (B). Even though there was a slight difference in the effect of the traffic level and region, asphalt binder was the parameter having the greatest effect on the asphalt pavement distress. In the case where the effect of multiple parameters was analyzed, the combination of the asphalt binder and base thickness showed a relatively strong effect.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.77-82
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• 2018

In South Korea, LM crops are not allowed to grow locally, but have been allowed to be imported as food and feed purposes. Currently, the typical LMO imports are continuously increasing in the region of South Korea. In 2014, we carried out a review of the environmental release monitoring of LM maize (Zea mays L.) in Gyeonggi-do of South Korea, and analyzed volunteer samples using strip test kits and polymerase chain reaction (PCR) methods. We thereby collected 44 volunteers of released LM maize in 169 locations around ports, from roadsides, feed factories and stockbreeding farmhouses. We found 4 positive samples at 3 sites using strip test kits. Based on the PCR analysis, the LM maize plants were found using event-specific primers. These results suggested that our monitoring is necessary to detect the presence of released LM maize in the natural environment of South Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.100-107
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• 2018

The objective of this study is to assess the strengthening effects of fiber reinforced polymer(FRP) sheets such as Carbon fiber, Glass fiber, and PET(polyethylene terephthalate) on reinforced concrete flexural members. Variables of theoretical analysis are types of strengthening materials, material properties and amount of strengthening materials. A virtual flexural member without FRP sheets was created as a control specimen to understand the structural behavior of the non-strengthened specimen in terms of elastic and ultimate cross section. In total, 11 specimens including one non-strengthened and ten strengthened specimens were investigated. Various variables such as types of strengthening, strengthening properties, and amount of strengthening were studied to compare the behavior of the control specimen with those of strengthened specimens with regard to moment-curvature relationship. Results of theoretical analysis showed that the moment capacity of strengthened specimens was superior to that of the control specimen. However, the control specimen indicated the best ductility among all the specimens. As the amount of strengthening increased, flexural performance was improved. Furthermore, the results indicated that the ductile effect of members was affected by the ultimate strain of FRP sheets. The strengthening effect on the damaged member was similar to that on the non-damaged one since there was less than 10% difference in terms of flexural strength and ductility. Therefore, even if a damaged member is treated as non-damaged for analysis there is probably no noticeable difference.

• KSBB Journal
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• v.14 no.4
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• pp.422-428
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• 1999

A transformat Alcaligence eutrophus GA5 harboring phbC gene from A. latus was cultivated for production of Poly(3-hydroxybutyrate-4-hydroxybutyrate)[P(3HB-4HB)] containing high molar fraction of 4-hydroxybutyrate(4HB)] containing high molar fraction of 4-hydroxybutyrate(4HB). Transformation did not influenced significantly on total cell growth, on total cell growth, concentration, and content of P(3HB-4HB), however, significantly influenced on 4HB molar fraction in P(3HB-4HB) increasing from 12.3 to 23.5 mol% after 48 h cultivation in two-stage using 1.0%(W/V) of ${\gamma}$-butyrolactone as a precursor compare to parent strain. Above increment may be due to the accelerated polymerization between 3HB and 4HB converted from precusor compound by amplified phbC gene. Citrate increased remarkbly total cell mass and P(3HB-4HB) concentration, but did not influenced on the molar fraction of 4HB, meanwhile, magnesium ion influenced on P(3HB-4HB) concentration and 4HB molar fraction significantly. The two-stage cultivation method was modified, in such a way minimizing P(3HB) accumulated inside of cell grown at first-stage, consquently, 26.3% of P(3HB-4HB) containing 61.0 mol% of 4HB fraction was obtained after 72hr. Furthermore, semi-homopolymeric P(4HB) containing 92.0 mol% of 4Hb was obtained, and its structure was confirmed by $^1$H-NMR.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.409-418
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• 2012

A modified standardized precipitation index was developed by considering the length of dry period and surface run-off effect. The official reports and newspapers on drought from 1973 to 2009 were quantified to evaluate drought indices. The developed index was evaluated using the receiver operating characteristic analysis. In order to suggest improved drought index, we cut the precipitation amount that may do not contribute the mitigation of drought and weight dry period by considering cumulative distribution, decile distribution of dry periods. Drought detection capability of the suggested index has improved by weighting of dry period effects and considering precipitation amounts contributing drought mitigation.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.109-121
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• 2013

This paper studied the characteristics of bearing capacity of railway reinforced with geosynthetic against repetitive loading of train. The railway that was based on the porous pavement substructure ground and reinforced with geosynthetic was copied. In order to analyze load carrying capacity of geosynthetic, we have had 3cases experiments - in the first case, the ground was non reinforced, second case was reinforced geocell and last case was reinforced geogrid - and all of them were reduced-scale laboratory tests. The results of the analyses indicated that the bearing capacity of the reinforced geogrid increases much more than the reinforced geocell. Residual deformation of the initial cyclic load was larger than the secondary cyclic loads.