• KOREAN JOURNAL OF CROP SCIENCE
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• 제48권1호
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• pp.1-7
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• 2003

In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30${\times}$14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 $\mu\textrm{m}$＋RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 $\mu\textrm{m}$＋RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.

• Journal of the Korean Applied Science and Technology
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• 제21권4호
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• pp.327-334
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• 2004

Cysteine-silver complexes were prepared and investigated the antimicrobial activity on rubber mat manufactured with waste rubber. We are exposed to harmful bacteria and fungi all the time. We manufactured antimicrobial mat to be imposed to mats that it can prevent generation of bacteria and microorganisms, and restrict their reproduction. Infection of medical devices causes significant morbidity and mortality. For aim of this study, we measured the antimicrobial mat manufactured with cysteine-Ag complex by CCD, FT-IR and NMR. The effect of mole ratio of cysteine-Ag complex on antimicrobial activity to bacteria and fungi is investigated. Reduction rate is evaluated using the Quinn method. Antimicrobial activity of complex on mole ratio 1:4 was effectively inhibited. The complexes had a better antibacterial activity than antifungal activity on rubber mat.

• Science of Emotion and Sensibility
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• 제15권2호
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• pp.177-182
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• 2012

Automotive sub-mat carpet for convenience and comfort of floor administration is additional supplemented floor mat. Sub Mat Backing of the current vehicle's materials reclaimed rubber, PVC, etc. are used, but secondary rubber and PVC Backing have bad sound absorption. Also rubber is heavy too. Contact surfaces between PET staple fiber, PET non-woven, PVC backing and car's floor carpet was measured the coefficient of friction for each sub-mat's non-slip evaluation. A surface of PET non-woven sub-mat has the highest coefficient of friction. Each of sample was observed by optical microscope the contact surfaces before and after. Contact surfaces of PET staple fiber sub-mat was changed increasingly to non-woven. This fact is shown that the sub-mat would be tangled between its contact surface and top of the floor carpet. It is expected to be highly non-slip. In case of PET non-woven sub-mat had not different for contact surfaces between before and after. And PVC backing was shown lower non-slip than other samples. The result of optical microscope and coefficient of friction is seems to be related.

• Journal of The Korean Society of Agricultural Engineers
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• 제52권3호
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• pp.97-104
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• 2010

The purpose of this study is to evaluate sediment yield reduction under various field slope conditions with rice straw mat. The Vegetative Filter Strip Model-W (VFSMOD-W) and Soil and Water Assessment Tool (SWAT) were used for simulation of sediment yield reduction effect of rice straw mat. The Universe Soil Loss Equation Practice factor (USLE P factor), being able to reflect simulation of rice straw mat in the agricultural field, were estimated for each slope with VFSMOD-W and measured soil erosion values under 5, 10, and 20 % slopes. Then with the regression equation for slopes, USLE P factor was derived and used as input data for each Hydrological Response Unit (HRU) in the SWAT model. The SWAT Spatially Distributed-HRU (SD-HRU) pre-processor module was utilized, moreover, in order to consider spatial location and topographic features (measured topographic features by field survey) of all HRU within each subwatershed in the study watershed. Result of monthly sediment yield without rice straw mat (Jan. 2000 - Aug. 2007) was 814.72 ton/month, and with rice straw mat (Jan. 2000 - Aug. 2007) was 526.75 ton/month, which was reduced as 35.35 % compared without it. Also, during the rainy season (from Jun. to Sep. 2000 - 2007), when without vs. with rice straw mat, monthly sediment indicated 2,109.54 ton and 1,358.61 ton respectively. It showed about 35.60 % was reduced depending on rice straw mat. As shown in this study, if rice straw mat is used as a Best Management Practice (BMP) in the sloping fields, rainfall-driven sediment yield will be reduced effectively.

• Korean journal of applied entomology
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• 제56권1호
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• pp.51-60
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• 2017

The striped fruit fly, Bactrocera scutellata, infests pumpkin flowers. Males are attracted to raspberry ketone (RK) and feed the attractant. This study was conducted to determine essential techniques to develop a male annihilation technique (MAT) of this insect pest. Effective attractants were screened in laboratory and field conditions. Both males and females were responsive to methyl eugenol (ME) in laboratory, though no flies were attracted to ME traps in field conditions. In contrast, cuelure (CL), which is a chemical derivative of RK, was effective to attract males of B. scutellata in both laboratory and field conditions. However, RK was equivalent or superior to CL when they were formulated in a form of wax dispenser. A pyrethroid insecticide along with the attractant was effective to attract and kill B. scutellata. Funnel trap was useful for MAT to confirm and count dead flies. These results indicate that MAT against B. scutellata consists of RK and bifenthrin in a wax type formulation, which is installed to a funnel type of trap. These essential factors would be useful to develop MAT applicable to control B. scutellata in fields.

• Journal of the Korean Applied Science and Technology
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• 제28권3호
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• pp.345-350
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• 2011

Antioxidant agent, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane were prepared and investigated the antioxidant activity on recycled rubber mat manufactured with waste tire powder. Mechanical properties of rubber mat are influenced by many factor such as compounding ingredients and state of cure, process of rubber, and fillers. Our study aim is to investigate influence of antioxidant activities on ozone cracking and the thermal aging time. In this work, the degradation of recycled rubber mat was studied and suggested mechanism to involve two-type of degradation, thermal aging and cracking both of which can be contained antioxidant or non-antioxidant agent.

• Mycobiology
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• 제37권4호
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• pp.247-250
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• 2009

Twenty-five isolates of Fusarium fujikuroi acquired from rice seeds and rice plants evidencing symptoms of Bakanae disease were evaluated to determine their mating types and characterize the formation of their sexual state. The mating types of the isolates were evaluated via multiplex PCR with the diagnostic primers of the mating-type (MAT) region: GFmat1a, GFmat1b, GFmat2c, and GFmat2d. Among the 25 isolates, 11 were identified as MAT-1 (male), and 14 as MAT-2 (female). Four MAT-1 isolates and three MAT-2 isolates were mated and cultured to evaluate the optimal culture conditions for the production of their sexual states. Among four tested media, 10% V8 juice agar proved optimal for the perithecial production of the isolates. The isolates also generated the largest numbers of perithecia when incubated at 23oC in alternating cycles of 12 hr fluorescent light and NUV fluorescent light and 12 hr darkness.

• Journal of the Korean Geosynthetics Society
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• 제18권1호
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• pp.91-101
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• 2019

Recently, small-scale excavation like ground cavity restoration and buried pipe replacement works are being carried out in urban area, in order to improve living convenience. This paper describes experiment results on the ground reinforcement method that can reduce the buried pipe damage, when the differential settlement occurred due to poor compaction of ground below the buried pipe. Plate load tests were conducted to evaluate a reinforcement effect of ground using concrete mat and expansion mat in the ground below the buried pipe. The results showed that the stress reduction ratio by concrete mat and expansion mat according to the surcharge load was about 46%~48% and 39%~42%, respectively. Therefore, the differential settlement of the buried pipe and the ground deformation below the buried pipes were reduced by the reinforcement effect of the concrete mat and expansion mat. This means that it is possible to prevent a buried pipe damage due to underground cavity and ground subsidence, if concrete mat and expansion mat are reinforced in the ground below the buried pipe or on the ground between the buried pipes.

• Communications of the Korean Mathematical Society
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• 제34권2호
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• pp.401-414
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• 2019

Let ${\mathcal{F}}$ denote an algebraically closed field with characteristic not two. Fix an integer $d{\geq}3$, let $Mat_{d+1}({\mathcal{F}})$ denote the ${\mathcal{F}}$-algebra of $(d+1){\times}(d+1)$ matrices with entries in ${\mathcal{F}}$. An ordered pair of matrices A, $A^*$ in $Mat_{d+1}({\mathcal{F}})$ is said to be LB-TD form whenever A is lower bidiagonal with subdiagonal entries all 1 and $A^*$ is irreducible tridiagonal. Let A, $A^*$ be a Leonard pair in $Mat_{d+1}({\mathcal{F}})$ with fundamental parameter ${\beta}=2$, with this assumption there are four families of Leonard pairs, Racah, Hahn, dual Hahn, Krawtchouk type. In this paper we show from these four families only Racah and Krawtchouk have LB-TD form.

• Journal of Sensor Science and Technology
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• 제8권6호
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• pp.481-486
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• 1999

Alumina electrostatic chucks for silicon wafer process with wide range of electrical resistivity were fabricated by controlling the amount of $TiO_2$ addition(0, 1.3, 2.0, 2.8 wt%). The dependence of electrostatic force on applied voltage, temperature and humidity was investigated. In addition, response characteristics on applied voltage and relationship between electrical resistivity and electrostatic force characteristics such as Coulomb force and Johnsen-Rahbeck force were discussed.