• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.153-164
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• 2015

The methods of design of mat foundation may be classified as the rigid method and the flexible method according to the assumptions used. In the rigid method, the mat is assumed to be infinitely rigid and the contact pressure is assumed planar distribution. However, the contact pressure is not planar but curved surface because the real mat is not rigid. Therefore, it is not precise to analyze the mat foundation using the rigid method, and so there is no choice but to accept an error. On the other hand, in the flexible method, the mat is considered as the plate on the elastic foundation. This elastic plate theory is for the infinite plate acting a concentrated load on the elastic foundation. However, the functions for the moment, shear, and the deflection by the flexible method are very complex, there are many difficulties for the designer to use them. Also, it is impossible to use the design aid figures as a substitute of the complex functions, because they do not cover the values at the critical sections for the moment and shear. Therefore, in this research, the simplified functions for the moment, shear, and the deflection are proposed by regression analysis for an designer to use easily the flexible method. The simplified functions are very accurate and very ease to use.

• Korean Journal of Plant Taxonomy
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• v.44 no.1
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• pp.39-50
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• 2014

Phylogenetic positions of Sedirea and Neofinetia were addressed using the chloroplast matK and the nuclear ITS sequences. We also evaluate the usefulness of the makers for the identification of species and localities. Sedirea and Neofinetia form an independent monophyletic genus, respectively, in both matK and nuclear ITS trees. The sister genus of the Neofinetia was Vanda in both trees. In addition, our trees support the separate recognition of the Neofinetia from Vanda rather than the inclusion of Neofinetia into Vanda. The sister group of the Sedirea was (Dimorphorchis(Pteroceras(Saccolabiun+Phalaeonopsis))) clade. The Dimorphorchis was one of the most probable sister genus to the Sedirea. The sister group relationship between Sedirea and Aerides was suggested by their similar morphology, but not supported in molecular trees. The identification of species and localities of Neofinetia was possible using our two molecular markers. However, several pseudo-gene sequences are discovered from the public data base. In addition, the horizontal gene transfer of chloroplast genomes is frequent events in orchid hybrids. Therefore, we need a careful evaluation for the data prior to systematic use. Generation of sequence data from multiple accessions of a species may helpful to reduce these types of error.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.129-136
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• 2011

To measure effects of surface cover on runoff and sediment discharge reduction using rainfall simulator, four(5 m${\times}$30 m scale) plot experiments were conducted in this study. Surface covers made with straw mat, Polyacrylamide (PAM), chaff, and sawdust were simulated 4 times under 31.1~44.4 mm/hr rainfall intensities. Compared with results from control plot, the time of runoff generation is delayed and outflow volume decreased with surface cover. Effects on runoff reduction of straw mat, PAM, sawdust and chaff ranged 4.7~81.5 % and runoff rate reduced by 6.5~76.1 % respectively, when compared with those from control plot. The percentage of decrease in sediment discharge were 99.7~99.8 % from straw mat+sawdust+PAM plots, 85.9~95.6 % from straw mat+PAM plots, and 98.5~99.4 % from straw mat+chaff+PAM plots. The runoff, sediment discharge, and SS concentration reduction efficiencies of the cover materials were outstanding when compared to control plot. It was analyzed that reduction of runoff and sediment discharge were mainly contributed by decrease in rainfall energy impact and flow velocity and increase of infiltration due to the surface cover materials. The results could be used as a base for the development of best management practices (BMPs) to reduce runoff, sediment discharge from sloping field.

• Journal of the Korean Geosynthetics Society
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• v.9 no.2
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• pp.1-9
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• 2010

At present, the sand mat method is actively used for improvement of soft ground. But, there are some problems related with sand mat which has been used as a way to accelerate consolidation settlement. First of all, insufficiency of sand due to imbalances in market supply and demand is the one of the biggest problems, which makes price high of sand and delays a term of total construction work. Moreover, it is necessary to preserve integrity of environment from natural disruption caused by indiscreet quarrying and dredging operation to supply sand for soil improvement construction site. This paper presents the feasibility study to use of Precious Slag Ball instead of sand mat as the replacing material through the basic soil property tests, the medium of discharge capacity test and analysis of settlement property. It is also evaluates the performance of Precious Slag Ball as a sand mat in terms of discharge capacity, ground settlement by the K-Embank program based on field experimental work.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.91-93
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• 1989

x $Pb(Sb_{1/2}Sn_{1/2})O_3-PbTiO_3-PbZrO_3$, (0.05$\leq$x$\leq$0.30) ternary compound ceramics were fabricated by the mixed oxide method. The sintering temperature and time were $1200{\sim}1300[^{\circ}C]$, 2 hour, respectively. Increasing the PSS contents, the transition temperatures were decreased. The relative dielectric constant and Curie temperature of the 0.30PSS-0.20PT-0.50PZ specimens were 372, 190[$^{\circ}C$]. The pyroelectric coefficient, figure of merits for pyroelectric current and detectivity of the 0.25PSS-0.25PT-0.50PZ specimens had the good values, $5.41{\times}10^{-8}[C/cm^{2}K]$, $27.72{\times}10^{-12}[Ccm/J]$, $7.65{\times}10^{-10}{Ccm/J]$, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.1
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• pp.41-48
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• 2017

Fine polymeric fibers have been gaining interest from the energy harvesting/storage, tissue, and bioengineering industries because of advantages such as the small diameter, high porosity, permeability, and similarities to a natural extracellular matrix. Electrospinning is one of the most popular methods used to fabricate polymeric fibers because it is not as limited in regards to the materials selection, and it does not require expensive or complex equipment. However, electrospun fibers have a severe aerodynamic instability because the small diameter fibers are able to pass through the atmospheric layer when there is a high electric field. As a result, electrospun fibrous mats have serious difficulties with controlling its shape and geometric properties. In this study, a hybrid nano/microfibrous mat is presented that is fabricated using electrospinning with two different solvent-based PCL solutions. This provides control of the fiber diameter, mat porosity, and mechanical properties. Various hybrid fibrous mats were fabricated after an experimental investigation of the effects of solvent on fiber diameter. It was then demonstrated that the mechanical properties and porosity of the fabricated various hybrid mats could be successfully controlled.

• The Korea Journal of Herbology
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• v.29 no.1
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• pp.27-33
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• 2014

Objectives : This study was carried out to identify DNA markers of "Allium sativum" be circulated from Korea and China, which is difficult to discriminate from morphological characters because of fragmental materials of bulb. That is, all these studies focused on the discrimination of Allium sativum L. But these day, Chinese A. sativum was in circulated Korean A. sativum in Korean medicine markets. Therefore, the purpose of our study was to develop molecular markers for discrimination between Korean A. sativum and imports from China. Methods : Materials were collected randomly from a markets in Korea and China and be analyzed with matK, ndhF and trnL-F regions of chloroplast DNA (cpDNA). We collected 45 A. sativum individuals from Korean and Chinese medicine markets, in 2013. Results : As a results, matK and ndhF regions of cpDNA was shown to be identify, Species that grow from warm place and cold place can divide as five SNP (Single nucleotide polymorphisms) markers in matK and ndhF genes. Also, in trnL-F regions, found one SNP that can divide Korean A. sativum and Chinese A. sativum. Conclusions : From the analysis of matK and ndhF regions of cpDNA, we presumed that three markers of cpDNA were found by useful marker that can distinguish Korean, Chinese, Warm place type, and Cold place type. Individual differences of Korean and Chinese was thought that appear in geographical difference and genetic difference by environment for long hour even if same species.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.189-189
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• 1982

This study was carried out to determine the possibility of making fiberboard through the dry forming process, utilizing the tannin-like material of the Asplund pulp from the silk worm oak as a binder. The fiberboard was made through paraformaldehyde treatment, spray of NaOH solution and adjustment of mat moisture content, by hot-pressing at $220^{\circ}C$, and 50-6-50kg/$cm^2$ pressure with 6-min. (0.6-1.8-3.6) three-stage pressing cycle. The results are summarized as follows: 1. The modulus of rupture value of fiberboard treated with NaOH solution was greater than that of untreated. The value was increased in proportion to the paraformaldehyde content from I to 5%, but there was no increasing between 5 and 7% paraformaldehyde content. The value became higher along with the increase of mat moisture content from 15% to 25%. 2. The water adsorption of fiberboard treated with NaOH solution was lower than that of untreated. The value was de"creased in proportion to the paraformaldehyde content from 1 to 5%, but there was no decreasing between 5 and 7% paraformaldehyde content.. 3. A good quality fiberboard (modulus of rupture value of about 250kg/$cm^2$) was made through 5% paraformaidehyde treatment and 3% treatment of 10% NaOH solution, when the mat moisture content was 25%. was 25%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.428-433
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• 1989

The objective of this experiment was to determine if there were feasible to transplant infant rice seedling for machine transplanting. Cultivars tested were Sobaegbyeo and Daecheongbyeo, ]aponica type cultivars. Infant seedling, young seedling and semi-adult seedling were raised with sailor rock wool in seedling tray from 1986 to 1988. Infant rice seedling raised more than 4 days after sowing with rock wool was uniform, and low in ratio of missing hill at machine transplanting. Tiller number per m$^2$ was more in infant rice seedling, young seedling and semi-adult seedling, in that order. Heading dates were not significantly different among seedlings applied, however rice plant sown directly was later 4 or 5 days than any other seedlings. Panicle number per m$^2$ was more in infant seedling than in semi-adult seedling, but ripened ratio was lower in infant seedling due to lodging. Thus there were not greatly different in yield among seedlings tested. Therefore infant rice seedling (more than 5cm in plumule length) raised for 7 days was most optimum, and rock wool would be used as a nursery soil instead of nursery soil for raising infant rice seedling in machine transplanting.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.1
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• pp.1-9
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• 2016

Newborn screening (NBS) is important if early intervention is effective in a disorder and if there are sensitive and specific biochemical markers to detect disorder. Methionine is a useful marker to detect abnormal methionine-homocysteine metabolism, especially homocystinuria which needs urgent medical intervention. However, hypermethioninemia could occur in other metabolic disorder including liver disease, tyrosinemia type I, methionine adenosyltransferase (MAT) I/III deficiency, glycine N-methyltransferase (GNMT) deficiency, or adenosylhomocysteine hydrolase deficiency. However, experience with NBS for homocystinurias and methylation disorders is limited. Especially, MAT I/III deficiency which is the most common cause of persistent hypermethioninemia have two inheritance, autosomal recessive (AR) and autosomal dominant (AD), and their clinical manifestation is different between AR and AD. Here, author reviewed recent articles of guideline and proposed guideline for homocystinuria and methylation disorder.