• Journal of Practical Agriculture & Fisheries Research
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• 제21권1호
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• pp.49-59
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• 2019

The field trial was performed to evaluate the rice growth and yield in different direct seeding methods after Italian Ryegrass Harvest The required time for seed emergence was for 7 ~ 8days in the tested direct seeding methods and there was high in seedling establishment in order of wet hill-seeding with iron-coated seeds > water seeding with iron-coated seeds > wet hill-seeding with soil coverage with pregerminated seeds. The rice plant height was shorter in the tested direct seeding methods than that of machine transplanting until 45day after seeding but there was not significant difference in terms of statistical analysis at 63day after seeding. The growth of tiller number in the rice plant was high in water seeding with iron-coated seeds and wet hill-seeding with soil coverage and low in wet hill-seeding with iron-coated seeds compared to machine transplanting. The yield component in the tested direct seeding methods was not significant difference in terms of statistical analysis. The milled rice yield in the tested direct seeding methods was higher 2 ~ 8% being with 4.94 ~ 5.24t/ha than that of machine transplanting but there was not significant difference in terms of statistical analysis. The percentage of head rice was low in the tested direct seeding methods compared to machine transplanting. The weedy rice was not occurred in the tested rice cultivation methods. In conclusion the direct seeding method would be recommended to be a suitable to in following by Italian ryegrass harvesting in southern area of Korea in terms of reduction in production cost and high income basis for rice growing farmers.

• Journal of Practical Agriculture & Fisheries Research
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• 제19권1호
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• pp.119-128
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• 2017

The field trial was performed to evaluate the rice growth and yield in different direct seeding methods. The required time for seed emergence was for 8~ 9days in the tested direct seeding methods and there was high in seedling establishment according to wet hill-seeding with iron-coated seeds> wet hill-seeding with soil coverage>water seeding with iron-coated seeds and water seeding with pregerminated seeds as the conventional treatment. The rice plant height was taller in wet hill-seeding methods than that of water seeding with broadcasting method but there was not significant difference in terms of statistical analysis at 75day after seeding except the water seeding with pregerminated seeds. The growth of tiller number in the rice plant was highest in water seeding with iron-coated seeds. The milled rice yield was highest in water seeding with iron-coated seed being with 6.4t/ha and percentage of head rice was the highest in wet hill-seeding and water seeding with iron-coated seeds.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 한국해안해양공학회 1992년도 정기학술강연회 발표논문 초록집
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• pp.72-76
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• 1992

평면파 수치모형 해석시 가상경계에 평행한 입사각을 갖거나, 다방향의 입사파가 가상경계로 동시에 입사되는 경우에는 무처리 시 수치 반사가 발생되므로 해에 악영향을 미친다. 따라서 이러한 경우에 대해 가상경계에서 파랑 Energy 투명하게 통과시키는 고차원 무반사 경계조건에 대해 연구하였다. 이들 조건식의 수학적 안정성을 분석하기 위해 phperbolic system에서 normal-mode 분석을 수행하였다. 1차 및 2차의 고차원 무반사 경계조건을 Galerkin 가중잔차법을 이용 유한요소 모형에 적용하였으며 이들에 대한 특성을 시험하기 위해 수치실험을 실시하였다.

• Journal of Practical Agriculture & Fisheries Research
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• 제15권1호
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• pp.63-73
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• 2013

The research was conducted to determine a seed germination and seedling establishment of rice plant under seed coating materials such as iron, silicate, and phyllite and under covered with silicate and iron coated & silicate covered in the puddled wet hill seeding and wet line seeding methods. The seedling establishment was high in silicate and untreated control of 100%>phyllite coating of 91.5%>silicate coating of 88%>iron coating and silicate covered of 86%>silicate covered of 75.5% in the puddled wet hill seeding method, respectively. At 35days after treatment there was high in seedling height at silicate covered of 23.8cm>control of 23.6cm>silicate coating of 21.4cm>phyllite coating of 20.2cm>iron coating and silicate covered of 16.8cm>iron coating of 15.4cm. In puddle wet line seeding method rice seedling establishment was high at control and silicate covered of 100%>iron coating and silicate covered by 97.5%>phyllite coating by 94.8%>iron coating by 86%. Seedling height was high in silicate covered of 22.1cm>control of 21.2cm>silicate coating of 20.0cm>phyllite coating of 19.0cm>iron coating of 17.7cm>iron coating and silicate covered of 17.0cm, respectively.

• Weed & Turfgrass Science
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• 제2권4호
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• pp.348-351
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• 2013

Weedy rice is one of the major problems in direct-seeded rice field, resulting in poor rice quality and low grain yield. This study was carried out to evaluate the conversion effect to machine transplanting after wet-direct- seeding for 3 years on weedy rice occurrence, in comparison of repeated wet-direct-seeding. Occurrence of weedy rice in the continuous wet-hill-seeded and broadcasted field for 3 years increased 4 folds, when compared with that in machine transplanted rice paddy. In the first year of wet-direct-seeded field converted from machine transplanting, weedy rice occurrence did not increase, demonstrating lesser weedy rice in wet-hill-seeded than broadcasted field. These results indicate that alternate cultivation of wet-hill-seeding and machine transplanting is more effective to prevent weedy rice occurrence than the repeated wet-direct-seeding method for 3 years.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제31권3B호
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• pp.305-308
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• 2011

In this study, generation methods of 3-D multi-directional random wave are examined using the fully non-linear numerical model with non-reflected wave generation system (LES-WASS-3D). Directional distribution functions obtained by EMLM method are compared for multidirectional random waves generated by various generation methods. As a results, it is revealed that multi-directional wave field can be simulated using LES-WASS-3D.

• 농업기술회보
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• 제49권2호
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• pp.33-34
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• 2012

벼 무논점파란 무논상태에서 종자를 점파형식으로 파종함으로써 파종의 균일도를 높이고, 입모 및 벼 생육이 고르게 자랄 수 있게 한다. 따라서 벼 직파를 하되, 입모 및 벼의 생육을 안정적으로 도모하여 마치 기계이앙으로 재배한 벼와 비슷한 효과를 보이는 벼 무논점파 재배기술을 농가현장에서 실증한 결과와 농민방응 및 기술보급 경향을 알아보자.

• Economic and Environmental Geology
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• 제57권1호
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• pp.51-71
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• 2024

Seismic exploration is one of the widely used geophysical exploration methods with various applications such as resource development, geotechnical investigation, and subsurface monitoring. It is essential for interpreting the geological characteristics of subsurface by providing accurate images of stratum structures. Typically, geological features are interpreted by visually analyzing seismic sections. However, recently, quantitative analysis of seismic data has been extensively researched to accurately extract and interpret target geological features. Seismic attribute analysis can provide quantitative information for geological interpretation based on seismic data. Therefore, it is widely used in various fields, including the analysis of oil and gas reservoirs, investigation of fault and fracture, and assessment of shallow gas distributions. However, seismic attribute analysis is sensitive to noise within the seismic data, thus additional noise attenuation is required to enhance the accuracy of the seismic attribute analysis. In this study, four kinds of seismic noise attenuation methods are applied and compared to mitigate random noise of poststack seismic data and enhance the attribute analysis results. FX deconvolution, DSMF, Noise2Noise, and DnCNN are applied to the Youngil Bay high-resolution seismic data to remove seismic random noise. Energy, sweetness, and similarity attributes are calculated from noise-removed seismic data. Subsequently, the characteristics of each noise attenuation method, noise removal results, and seismic attribute analysis results are qualitatively and quantitatively analyzed. Based on the advantages and disadvantages of each noise attenuation method and the characteristics of each seismic attribute analysis, we propose a suitable noise attenuation method to improve the result of seismic attribute analysis.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 한국해안해양공학회 1998년도 정기학술강연회 발표논문 초록집 Annual Meeting of Korean Society of Coastal and Ocean Engineers
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• pp.78-83
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• 1998

흐름이 존재하는 수역을 파가 전파할 때 파는 흐름과의 상호작용에 의해 그 특성이 변형된다. 예를 들면 파와 흐름의 진행 방향이 같을 때는 파고의 감소, 반대일 때 파고의 증가로 나타난다. 후자의 경우 흐름에 의해 반사파가 생성될 것으로 사료되나 실제 해역에서 이러한 현상을 관측한 예는 거의 찾아보기 어렵다. 동해안의 경우 통상 관측지점에서 흐름의 세기가 작기 때문에 흐름에 의한 파의 굴절 현상이 잘 나타나지 않는다. (중략)

• Weed & Turfgrass Science
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• 제6권3호
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• pp.196-202
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• 2017

This study was conducted to investigate the change of yield and quality according to seeding time and planting density and to determine effective weed control method in wet-hill-seeding use black colored rice. The most effective weed control system was application of bromobutide thiobencarb five days before seeding followed by bensulfuron mefenacet thiobencarb 12 days after seeding (barnyardgrass at 2.5-3.0 leaf stage). The seedling stand by seeding time and planting density increased with the delay seeding time and high planting density. The heading dates were delayed as the seeding time became late but no difference was found between planting density. The anthocyanin content of black colored rice was higher at late seeding time and lower planting density. The yield of full colored rice was high 80 plants per $3.3m^2$ in seeding on May 30 and June 10. This information could be useful for spreading rice direct seeding by inducing stabilization of wet-hill-seeding use black colored rice.