• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.607-612
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• 2019

The softness of the crashpad part is one of the important factors which affect the interior perceived quality of the vehicle interior. And while improving the softness of the crashpad part, every effort to lower the production cost has been going on. The PU foaming process for the crashpad part depends on the understanding of a lot of processes, tools and material properties. Therefore, to achieve the requirement of the customer for the interior part's visual quality, the integrated design techniques are investigated to correlate the processes, tool design, material design and the computer aided analysis. In this paper, IMG (In Mold Grain) designed concept is firstly developed to integrate the skin preforming, plastic injection molding of the substrate and the foaming process in a tool within reduced processes. Through the application of this technology, softness of crashpad is improved by 40% compared to the conventional vacuum molding method, and the existing process is reduced by 50% by integrating the injection process and the manufacturing process. And by integrating the injection mold and the skin mold and removing the foaming mold, the number of molds are reduced from 3 to 1, resulting in 20% reduction in the cost of applying a medium-sized passenger car.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.428-434
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• 2021

To study whether the area under the cultivation of Italian ryegrass (IRG) has increased with rise in global temperatures, we investigated the effects of climatic variables on seed productivity in different parts of Gangwon-do, South Korea. Specifically, IRG was cultivated in the western (Gangneung), central (Wonju), and northern (Chuncheon) parts of Gangwon-do. The heading date of IRG in Gangneung was earlier than that in the other regions. Moreover, the values of agronomic traits, including spikelets per spike, grains per spike, and thousand-grain weight, were lower in Chuncheon. However, there were no differences spikelets per spike and grains per spike between Wonju and Gangneung. Additionally, the thousand-grain weight and seed production were higher in Gangneung. Statistical correlation analysis between climatic variables and agronomic traits revealed that the mean daily minimum temperature was positively correlated with seed formation-related traits in April and seed maturity-related traits in May. In the light of rising minimum temperatures in Gangwon-do, Gangneung, Chuncheon and Wonju are suitable areas for IRG cultivation with optimal seed productivity.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.491-500
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• 2022

It has been noted that an accurate estimation of wind loads on offshore structures such as an FLNG (Liquefied Natural Gas Floating P roduction Storage Offloading Units, LNG FPSOs) with a large topside plays an important role in the safety design of hull and mooring system. Therefore, the present study aims to develop a computational model for estimating the wind load acting on an FLNG. In particular, it is the sequel to the previous research by the author. The numerical computation model in the present study was modified based on the previous research. Numerical analysis for estimating wind loads was performed in two conditions for an interval of wind direction (α), 15° over the range of 0° to 360°. One condition is uniform wind speed and the other is the NPD model reflecting the wind speed profile. At first, the effect of sand-grain roughness on the speed profile of the NPD model was studied. Based on the developed NPD model, mesh convergence tests were carried out for 3 wind headings, i.e. head, quartering, and beam. Finally, wind loads on 6-degrees of freedom were numerically estimated and compared by two boundary conditions, uniform speed, and the NPD model. In the present study, a commercial RANS-based viscous solver, STAR-CCM+ (ver. 17.02) was adopted. In summary, wind loads in surge and yaw from the wind speed profile boundary condition were increased by 20.35% and 34.27% at most. Particularly, the interval mean of sway (45° < α <135°, 225° < α < 315°) and roll (60° < α < 135°, 225° < α < 270°) increased by 15.60% and 10.89% against the uniform wind speed (10m/s) boundary condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.138-145
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• 1988

The effect of directions (north to south vs east to west) of planting row, planting intensities (10/15, 15/15, 20/15, 25/15 cm/cm) and the number of rows consecutively (1,2, 3,4) for both the CMS and pollen parent in alternation, on the seed yield of CMS of rice was tested with a breeding line V20A/Iri342$\^$*8/. When the planting row was made in vertical direction to the wind direction during anthesis, the seed yield was higher than the other direction regardless the planting densities and number of rows consecutive. Seed yield increased as high as 46.9%. The higher planting intensities up to 10/15 cm/cm yielded the higher hybrid seeds. The highest yield was 81.2 kg/ha. The yield variation among plants within a plot and among the plants within a replication was relatively large. Increased pollen parent row numbers caused increased grain fertility per plant, but the seed yield was increased by reduced pollen parent row number. Reduced CMS parental row numbers caused increased grain fertility per plant, but the seed yield was increased by increased CMS parental row numbers. Considering the hybrid seed yield, parental seed yield and operational convenience, 4 rows of CMS and 1 row of pollen parent in alternate with 20/15 or 25/15 (cm/cm) planting densities seemed to be the rational layout.

• Journal of Korean Society of Rural Planning
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• v.28 no.1
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• pp.17-26
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• 2022

It is necessary to prepare a stable production base in advance for a change in the global grain market, and it is required to prepare comprehensive countermeasures such as securing technical skills and cultivation technology. Therefore, Korea, which relies on imports of major grains other than rice, could be exposed to a food crisis at any time unless the self-sufficiency rate of grains is improved. In order to respond to this new food crisis, it is necessary to find ways to efficiently utilize rice fields to increase the domestic grain self-sufficiency rate. From this point of view, interest and demand for the generalization of farmland that can be used as paddy fields and returned to paddy fields are increasing, and related research is also being continuously performed. In order to select a multipurpose farmland project site, this study extracted farmland containing 10% or more purchased and stockpiled farmland through spatial analysis (buffer, dissolve, intersect, etc.), and finally presented areas subject to multipurpose farmland projects. The target site for the multipurpose farmland project was finally selected by integrating data onto a point-by-point basis so that the current status of farmland purchased and stockpiled, Farm Manager Registration Records, and the Korean Soil Information System data (drainage classes, surface soil texture, field-suitability classification, etc.) can be used in combination. There are 175 areas where the multipurpose farmland is possible. Incheon 2, Gyeongbuk 40, Gangwon 2, Chungbuk 7, Chungnam 48, Jeonbuk 34, Jeonnam 19, Gyeongbuk 15, Gyeongnam 8. Chungcheongnam-do has the most target site for the multipurpose farmland project, and Gangwon-do is the least. It is expected to contribute to new commercialization and business expansion by deriving business areas by identifying the scale of the farmland multipurpose farmland project using Farm Manger Registration Records and spatial data.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.39-51
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• 1976

As an accempt to increase thc efficiency of land use and the food production to achieve the national goal in the food self-sufficiency, nine cropping systems on the upper-land were examined in pure-stand and in mixtures of soybean, corn, potato and radish. The important conclusions of this study were summarized as follows; 1. The flowering date of soybean was two or three days earlier in pure-stand than in the mixture with corn. The maturing date two days earlier in the pure-stand than in the mixture with corn. The flowering and maturing dates were not different among various cropping systems in corn. 2. The stem length of soybean was significantly different among various cropping systems. Soybean in pure-stand was shorter in stem length than with corn. 3. The number of pods per soybean plant did not give any significant differences among various cultivation methods. 4. The length of internode and the number of nodes per soybean plant in the mixture with corn were greater than in the pure-stand. In the number of branches per plant this was reversed. 5. The average stem dry weight of soybean per 10a was not significantly different among various cultivation methods. 6. The soybean yield per 10a in the pure-stand was obviously greater than the mixture and there were significant differences among cultivation method within the mixture with corn in soybean yield. 7. The 1,000-grain weight of soybean was significantly different and those in the pure-stand was heavier than those in the mixture with corn. 8. Grain weight per soybean plant and the stem diameter in the pure-stand were significantly lesser than those in the mixture with corn. 9. In the comparisons of corn in the pure-stand and in the mixture with soybean, plant height, number of ear per 10a, mean ear weight and remember of grain per plant, 100-grain weight, ear length, ear girth and number of ear pel plant were not significantly different among various cultivation methods except for the grain yield per 10a. 10. In the economic analysis, the mixture with soybean and corn gave the greatest gross income. The combination 7 was the best which was 47.6% increase income comparing with the soybean pure-stand. 11. As it can be assumed, soybean plant was influenced greatly than corn by various cropping system. It is necessary to study more complex cropping system finding and giving more desirable multiple cropping system for the farmer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.105-112
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• 2017

The mixing of rice and brown rice produced in different years is banned in Korea by the grain management act. However, there has been no reported method for discriminating the production year of rice. The objective of this study was to develop a method for discriminating the production year of rice and brown rice based on their phospholipids content. One hundred rice samples and 130 brown rice samples produced between 2012 and 2015 were collected. Twelve phosphatidylcholine components were analyzed by liquid chromatography-tandem mass spectrometry. Phosphatidylcholine was used as an internal standard to calculate the peak intensity of the samples. A statistical analysis of the results showed that the centroid distance between the stale and new rice was 4.16 and the classification ratio was 97%. To verify the calculated discriminant, 61 and 40 rice samples were collected. The accuracy of discrimination was 82% by primary verification and 80% by secondary verification. The statistical analysis of brown rice showed that the centroid distance between the stale and new brown rice was 3.14 and the classification ratio was 96%. To verify the calculated discriminant, 10 samples of new rice and 30 samples of stale rice were collected and the accuracy of discrimination was 93%. The accuracy of discrimination for rice stored at room temperature was 57.9-92.1% and that for rice stored at a low temperature was 86.8-94.7%, depending on the storage period. For brown rice, the detection accuracy was 94.7-100% at room temperature and 92.1-100% at a low temperature, depending on the storage period. The accuracy of discrimination for rice was affected by the storage temperature and time, while that for brown rice was more than 92% regardless of the storage conditions. These results suggest that the developed discriminant analysis method could be utilized to determine the production year of rice and brown rice.

• Journal of Life Science
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• v.32 no.12
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• pp.929-937
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• 2022

To investigate the anti-inflammatory activity of the grains of sorghum, three Sorghum bicolor (L.) Moench variants (Hwanggeumchal, Huinchal, and Chal) being cultivated in Korea, the 80% ethanol (EtOH) extracts of individual sorghum grains were compared for their inhibitory activity against nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophage cell line. Among them, the EtOH extract of sorghum Hwanggeumchal grains could exert the highest inhibitory effect on the LPS-induced NO production. However, under these conditions, the viability of RAW264.7 cells was not affected. When the EtOH extract of sorghum Hwanggeumchal grains was sequentially fractionated with n-hexane, methylene chloride (MC), ethyl acetate (EtOAc), and n-butanol, the anti-NO production activity was predominantly detected in both MC and EtOAc fractions. In particular, treatment with the MC fraction reduced dose-dependently the expression levels of iNOS, COX-2 and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in LPS-stimulated RAW264.7 cells. Simultaneously, the MC fraction could prevent LPS-induced activating phosphorylation of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). HPLC analysis of the MC fraction showed gentisic acid and naringenin as the major phenolic components. Both gentisic acid and naringenin commonly exhibited a potent inhibitory activity against LPS-induced NO production in RAW264.7 cells. Together, these results provide the evidence of the inhibitory activity of Hwanggeumchal grains on LPS-induce inflammatory responses in RAW264.7 murine macrophage cells and also suggest that sorghum grains possess beneficial health effects which can be applicable in development of the grain-based functional foods.

• Journal of the Korean Magnetics Society
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• v.12 no.1
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• pp.34-40
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• 2002

In order to improve the microstructure of the strip cast Nd-Fe-B alloys that are frequently used for production of high energy sintered magnets, influence of various strip casting conditions on the microstructure and phase formation and distribution were investigated. Nd-Fe-B strips consisting of microstructures suitable for preparation of high energy sintered magnets could be obtained when the wheel speed was below 5 m/s. The compositional limit that can avoid the crystallization of free iron in the as-cast state was estimated to be Nd$\_$14/Fe$\_$79/B$\_$7/. Regardless of the compositional variation, <001> preferred orientation of Nd$_2$Fe$\_$14/B normal to the strip surface was always occurred below 5 m/s, which would eventually enhance the grain alignment during pressing the powder under a magnetic field. While the coercivity of the strip cast alloys increased with the increase of the wheel speed, mainly due to the refinement of Nd$_2$Fe$\_$14/B grains, it decreased with the reduction of Nd content in the alloy composition as the formation of free iron increased.

• Journal of Magnetics
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• v.7 no.3
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• pp.63-71
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• 2002

Three fabrication techniques for forming thin barrier layer with uniform thickness and large barrier height in magnetic tunnel junction (MTJ) are discussed. First, the effect of immiscible element addition to Cu layer, a high conducting layer generally placed under the MTJ, is investigated in order to reduce the surface roughness of the bottom ferromagnetic layer, on which the barrier is formed. The Ag addition to the Cu layer successfully realizes the smooth surface of the ferromagnetic layer because of the suppression of the grain growth of Cu. Second, a new plasma source, characterized as low electron energy of 1 eV and high density of $10^{12}$ $cm^{-3}$, is introduced to the Al oxidation process in MTJ fabrication in order to reduce damages to the barrier layer by the ion-bombardment. The magnetotransport properties of the MTJs are investigated as a function of the annealing temperature. As a peculiar feature, the monotonous decrease of resistance area product (RA) is observed with increasing the annealing temperature. The decrease of the RA is due to the decrease of the effective barrier width. Third, the influence of the mixed inert gas species for plasma oxidization process of metallic Al layer on the tunnel magnetoresistance (TMR) was investigated. By the use of Kr-O$_2$ plasma for Al oxidation process, a 58.8 % of MR ratio was obtained at room temperature after annealing the junction at $300{^{\circ}C}$, while the achieved TMR ratio of the MTJ fabricated with usual Ar-$0_2$ plasma remained 48.4%. A faster oxidization rate of the Al layer by using Kr-O$_2$ plasma is a possible cause to prevent the over oxidization of Al layer and to realize a large magnetoresistance.