• 한국초지조사료학회지
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• 제37권1호
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• pp.50-55
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• 2017

In attempt to avoid crop damage through wild bird's picking, this study was designed with aim to evaluate several pre-sowing soybean seed coatings for optimum yield in corn-soybean mixed forage. It was investigated under four cropping treatments, viz. 1) corn sole, 2) corn mixed with soybean without any coating, 3) corn with iron coated soybean and 4) corn with thiram coated soybean. Each treatment had three replicates and corn sole was control treatment. Pioneer (P1184) and crossbred ($PI483463{\times}Hutcheson$) seeds were used for corn and soybean, respectively. The trial was conducted under randomized block design from $5^{th}$ June to $23^{rd}$ September, 2015. Data were an alyzed through ANOVA technique using SAS9.1.3 software. Results depicted that survivability of soybean against wild birds damage was found better (p<0.05) in thiram coating which was higher than iron coating and control treatment but later on thiram coating had adverse effects on subsequent growth of soybean plants. Corn stalk height was decreased (p<0.05) in thiram coating, whereas corn ear height was reduced in iron coating treatment. Iron coating enhanced (p<0.05) height of soybean plant (p<0.05) better than that of thiram coating. Soybean seed coatings didn't influence dry matter yield and nutritive value in terms of total digestible nutrients yield in corn soybean mixed forage. Conclusively, although presowing thiram coating enhanced survivability of soybean plants against wild bird damage but had adverse effects on its subsequent growth. However, soybean seed coatings didn't influence yield and nutritive value of corn soybean intercropping forage.

• 한국작물학회지
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• 제53권spc호
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• pp.72-77
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• 2008

This study was carried out to determine the response of the rice yield and grain quality by rice leaf folder (RLF, Cnaphalocrocis medinalis G.) and identify the damages caused by different transplanting dates, nitrogen amounts and chlorophyll amounts (SPAD value) of rice leaf. As the damage degree of RLF was getting severer, the ripened grain rate and 1000-grain weight were decreased and due to the increasing of chalky rice rate the rate of head rice was reduced. Therefore, the yield of head rice was decreased by 36% in heavily damaged rice plant. Among the physicochemical characteristics, protein content of rice grain was increased but amylose content was reduced, consequently, the palatability was deteriorated in heavily damaged rice by RLF. The degree of damage of RLF was getting serious as transplanting date was delayed and as the amount of nitrogen was increased. In the relationship between the SPAD value and the damage degree of RLF, as the SPAD value was increased by nitrogen fertilizing, the damage degree was also increased exponential functionally.

• 한국초지조사료학회지
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• 제41권4호
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• pp.287-294
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• 2021

본 연구는 기계학습을 통한 수량예측모델을 이용하여 이상기상에 따른 WCM의 DMY 피해량을 산출하기 위한 목적으로 수행하였다. 수량예측모델은 WCM 데이터 및 기상 데이터를 수집 후 가공하여 8가지 기계학습을 통해 제작하였으며 실험지역은 경기도로 선정하였다. 수량예측모델은 기계학습 기법 중 정확성이 가장 높은 DeepCrossing (R²=0.5442, RMSE=0.1769) 기법을 통해 제작하였다. 피해량은 정상기상 및 이상기상의 DMY 예측값 간 차이로 산출하였다. 정상기상에서 WCM의 DMY 예측값은 지역에 따라 차이가 있으나 15,003~17,517 kg/ha 범위로 나타났다. 이상기온, 이상강수량 및 이상풍속에서 WCM의 DMY 예측값은 지역 및 각 이상기상 수준에 따라 차이가 있었으며 각각 14,947~17,571 kg/ha, 14,986~17,525 kg/ha 및 14,920~17,557 kg/ha 범위로 나타났다. 이상기온, 이상강수량 및 이상풍속에서 WCM의 피해량은 각각 -68~89 kg/ha, -17~17 kg/ha 및 -112~121 kg/ha 범위로 피해로 판단할 수 없는 수준이었다. WCM의 정확한 피해량을 산출하기 위해서는 수량예측모델에 이용하는 이상기상 데이터 수의 증가가 필요하다.

• Nuclear Engineering and Technology
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• 제44권7호
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• pp.791-798
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• 2012

Since standardized fracture test specimens cannot be easily extracted from in-service components, several alternative fracture toughness test methods have been proposed to characterize the deformation and fracture resistance of materials. One of the more promising alternatives is the local approach employing the SP(Small Punch) testing technique. However, this process has several limitations such as a lack of anisotropic yield potential and tediousness in the damage parameter calibration process. The present paper investigates estimation of ductile fracture resistance(J-R) curve by FE(Finite Element) analyses using an anisotropic damage model and enhanced calibration procedure. In this context, specific tensile tests to quantify plastic strain ratios were carried out and SP test data were obtained from the previous research. Also, damage parameters constituting the Gurson-Tvergaard-Needleman model in conjunction with Hill's 48 yield criterion were calibrated for a typical nuclear reactor material through a genetic algorithm. Finally, the J-R curve of a standard compact tension specimen was predicted by further detailed FE analyses employing the calibrated damage parameters. It showed a lower fracture resistance of the specimen material than that based on the isotropic yield criterion. Therefore, a more realistic J-R curve of a reactor material can be obtained effectively from the proposed methodology by taking into account a reduced load-carrying capacity due to anisotropy.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• Structural Engineering and Mechanics
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• 제55권3호
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• pp.511-523
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• 2015

Damaged steel-concrete composite girders can be repaired and retrofitted by epoxy-bonded carbon fiber-reinforced polymer (CFRP) sheets to the critical areas of tension flanges. This paper presents the results of a study on the behavior of damaged steel-concrete composite girders repaired with CFRP sheets under static loading. A total of seven composite girders made of I20A steel sections and 80mm-thick by 900mm-wide concrete slabs were prepared and tested. CFRP sheets and prestressed CFRP sheets were used to repair the specimens. The specimens lost the cross-sectional area of their tension flanges with 30%, 50% and 100%. The results showed that CFRP sheets had no significant effect on the yield loads of strengthened composite girders, but had significant effect on the ultimate loads. The yield loads, elastic stiffness, and ultimate bearing capacities of strengthened composite girders had been changed as a result of prestressed CFRP sheets, the utilization ratio of CFRP sheets could be effectively improved by applying prestress to CFRP sheets. Both the yield loads and ultimate bearing capacities had been changed as a result of steel beam's flange damage level and CFRP sheets could cover the girders' shortage of bearing capacity with 30% and 50% flange damage, respectively.

• 국제강구조저널
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• 제18권4호
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• pp.1107-1124
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• 2018

The structural behavior of reinforced concrete coupled shear wall structures is greatly influenced by the behavior of their coupling beams. This paper presents a process of the seismic analysis of reinforced concrete coupled shear wall-frame system linked by hysteretic dampers at each floor. The hysteretic dampers are located at the middle portion of the linked beams which most of the inelastic damage would be concentrated. This study concerned particularly with wall-frame structures that do not twist. The proposed method, which is based on the energy equilibrium method, offers an important design method by the result of increasing energy dissipation capacity and reducing damage to the wall's base. The optimum distribution of yield shear force coefficients is to evenly distribute the damage at dampers over the structural height based on the cumulative plastic deformation ratio of the dissipation device. Nonlinear dynamic analysis indicates that, with a proper set of damping parameters, the wall's dynamic responses can be well controlled. Finally, based on the total plastic strain energy and its trend through the height of the buildings, a prediction equation is suggested.

• Earthquakes and Structures
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• 제5권6호
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• pp.657-678
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• 2013

For economical earthquake resistant design of cable-stayed bridge tower, the use of energy dissipation systems for the earthquake protection of steel structures represents an alternative seismic design method where the tower structure could be constructed to dissipate a large amount of earthquake input energy through inelastic deformations in certain positions, which could be easily retrofitted after damage. The design of energy dissipation systems for bridges could be achieved as the result of two conflicting requirements: no damage under serviceability limit state load condition and maximum dissipation under ultimate limit state load condition. A new concept for cable-stayed bridge tower seismic design that incorporates sacrificial link scheme of low yield point steel horizontal beam is introduced to enable the tower frame structure to remain elastic under large seismic excitation. A nonlinear dynamic analysis for the tower model with the proposed energy dissipation systems is carried out and compared to the response obtained for the tower with its original configuration. The improvement in seismic performance of the tower with supplemental passive energy dissipation system has been measured in terms of the reduction achieved in different response quantities. Obtained results show that the proposed energy dissipation system of low yield point steel seismic link could strongly enhance the seismic performance of the tower structure where the tower and the overall bridge demands are significantly reduced. Low yield point steel seismic link effectively reduces the damage of main structural members under earthquake loading as seismic link yield level decreases due their exceptional behavior as well as its ability to undergo early plastic deformations achieving the concentration of inelastic deformation at tower horizontal beam.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.349-349
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• 2017

This study was performed in order to investigate disease, insect damage, growth and yield characteristics of green maize by organic paddy-upland rotation system. This experiment also was to select optimum variety for organic paddy-upland rotation cultivation. This experiment was conducted at Anseong-si Gyeonggi province of Korea in 2016. The varieties used in this study are green maize of total 8 varieties. Green maize was planted at rotational upland field and continuing upland field and tested for comparison. In case of average occurrence of 4 major diseases for green maize, rotational upland field was higher than that of continuing upland field. Heukjinjuchal and Daehakchal were the lowest occurrence by less than 2% among 8 varieties. Average damage of 8 varieties by Ostrinia furnacalis larva, which is the main pest in green maize was higher in rotational upland field than that of continuing upland field. Chalok 4 and Heugjeom 2 were judged to be resistant varieties to 4 major diseases among 8 varieties. The average yield of green maize per 10a in rotational upland field decreased to 85% level of continuing upland field and Chalok 4 showed the highest yield by 789.0 kg/10a among 8 varieties. The most suitable varieties in organic paddy-upland rotation system were judged to be Chalok 4, Heukjinjuchal and Heukjeom 2.

• Structural Engineering and Mechanics
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• 제65권5호
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• pp.547-556
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• 2018

Based on the shaking table tests of a 1:3.52 scale one-bay and one-story ancient wooden structure, a simplified structural mechanics model was established, and the structural state equation and observation equation were deduced. Under the action of seismic waves, the damage rule of initial stiffness and yield stiffness of the joint was obtained. The force hammer percussion test and finite element calculations were carried out, and the structural response was obtained. Considering the 5% noise disturbance in the laboratory environment, the stiffness parameters of the mortise-tenon joint were identified by the partial least squares of singular value decomposition (PLS-SVD) and the Extended Kalman filter (EKF) method. The results show that dynamic and static cohesion method, PLS-SVD, and EKF method can be used to identify the damage degree of structures, and the stiffness of the mortise-tenon joints under strong earthquakes is reduced step by step. Using the proposed model, the identified error of the initial stiffness is about 0.58%-1.28%, and the error of the yield stiffness is about 0.44%-1.21%. This method has high accuracy and good applicability for identifying the initial stiffness and yield stiffness of the joints. The identification method and research results can provide a reference for monitoring and evaluating actual engineering structures.