• Computers and Concrete
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• v.23 no.2
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• pp.121-131
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• 2019

Due to the heterogeneity nature of the concrete, it is difficult to simulate the hyperdynamic behaviour and crack trajectory of concrete material when subjected to explosion loads. In this paper, a 3D nonlinear numerical study was conducted to simulate the hyperdynamic behaviour of concrete under various loading conditions using Riedel-Hiermaier-Thoma (RHT) model. Detailed calibration was conducted to identify the optimal parameters for the RHT model on the material level. For the component level, the calibrated RHT parameters were used to simulate the failure behaviour of plain concrete (PC) slab under free air blast load. The response was compared with an available experimental result. The results show the proposed numerical model can accurately simulate the crack trajectory and the failure mode of the PC slab under free air blast load.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.6
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• pp.11-20
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• 2007

This paper proposes a new efficient method to detect ellipses using a segment merging based Randomized Hough Transform. The key idea of the proposed method is to separate single line segments from an edge image, to estimate ellipses from any pair of the single line segments using Randomized Hough Transform (RHT), and to merge the ellipses. This algorithm is able to accuracy estimate the number of ellipses and largely improves the computational time by reducing iterations.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.65-74
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• 2000

The sensitivity of a mehtanogen and sulfate-reducing bacterium isolated from a sea-based landfill site Cd$^{2+}$ and CU$^{2+}$ was studied. Methanogens and sulfate-reducing bacteria in leachates of the waste disposal site were enumerated using the MPN method. Methanobacterium thermoautotrophicum KHT, isolated from the leachate, could not grow at 0.5 mM Cd$^{2+}$ or 1.0 mM CU$^{2+}$. Desulfotomaculum sp. RHT, isolated from the same leachate, was able to insolubilization 3.0 mM Cd$^{2+}$ or 2.0 mM CU$^{2+}$ by production of hydrogen sulfide. When strains KHT and RHT were cultured together in the presence of the heavy metals, strain KHT could grow at high heavy metal concentrations after insolubilization of the metals by strain RHT. strain RHT.

• Journal of Ocean Engineering and Technology
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• v.29 no.1
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• pp.70-77
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• 2015

The purpose of this study was to provide fundamental data for an anchor collision simulation of an FCM (flexible concrete mattress). Numerical material models (elastic-perfectly plastic model, Drucker-Prager model, and RHT concrete model) were compared. ANSYS Explicit Dynamics was used for collision analyses. An FE model was used for the anchor, FCM, andreinforcement bars. The results showed that the behavior of the FCM was verydifferent that those ofthe material models. In particular, the effect of the pressure dependent strength was most noticeable among the properties of concrete.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.720-726
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• 1995

Chemical components relevant to the characteristic taste of the Korean native persimmon(Diospyros kaki, Thumb) leaf tea were analyzed. Samples were processed by using three different methods ; SHT(steamed and then hot-air dried), DHT(dried in the shade, steamed and then hot-air dried) and RHT(roasted and then hot-air dried). The components analyzed were general compositions of dried perisimmon leaves and extracted solution. The composition of moisture, ash, crude lipid and total nitrogen did not show significant variation among different processing methods of the persimmonleaf tea. The contents of caffeine, tannin and vitamin C in persimmon leaf tea were in the range of $178.4~209.8{\mu}mol/g$, 29.1~38.5mg% and 325.3~2084.7mg%, respectively. The vitamin C content was significantly higher in the RHT than other treatments. The contents of caffeine, tannin and vitamin C in the tea extracted solution were in the range of $101.5~130.1{\mu}mol/g$, 15.4~25.9mg% and 111.0~1274.3mg%, respectively. The vitamine C in the tea solution was the highest in the RHT treatment and 61.1% of vitamin C in the leaf tea was extracted out in these processing methods. The major amino acids contained in the leaf tea were in decreasing order glutamic acid, aspartic acid, leucine and phenylalanine, these four amino acids consisting 38.9~39.8% of the total amino acid contained in the persimmon leaf tea. The major amino acids contained in the tea solution were glutamic acid, proline, histidine and arginine. Six kinds of 5'-nucleotides, CMP, AMP, UMP, IMP, GMP and hypoxanthine were detected and CMP was the most abundant component in fresh leaf, leaf tea and tea solution. The second highest 5'-nucleotides in both leaf tea and tea solutions were GMP, AMP and UMP in all processing method. The highest free sugar contained in the fresh leaf tea and tea solution was sucrose.

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.377-383
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• 2011

This study proposed the new method of discerning the assembled parts and presuming the position of central point in a Cowl Cross Bar (CCB) using a Charge-Couple Device (CCD) camera attached to a robot in the auto assembly line. Three control points of an ellipse were decided by three reference points, which were equally distanced. The radii of these reference points were determined by the size of the object, and the repeated presumption secured the precise determination. The comparison of the central point of ellipse presumed by Randomized Hough Transform (RHT) with the part information stored in a database was used for determining the faulty part in an assembly. The method proposed in this study was applied for the real-time inspection of elliptical parts, such as bolt, nut hole and so on, connected to a CCB using a CCD camera. The findings of this study showed that the precise decision on whether the parts are inferior or not can be made irrespective of the lighting condition of industrial site and the noises of the surface of the part. In addition, the defect decision on the individual elliptic parts assembled in a CCB showed more than 98% accuracy within a 500-millisecond period at most.

• Explosives and Blasting
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• v.41 no.3
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• pp.13-25
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• 2023

The conventional bench blasting method uses the bottom initiation in all blast holes in a round, whereas the MDS (mixture detonation system) method applies the bottom and top initiations alternately according to the spatial position or temporal sequence of each blast hole. The former and latter are respectively called the SMDS (spatial MDS) and TMDS (temporal MDS) methods. Another variant called MMDS (modified MDS) is designed for the specific use in the site having a fly-rock problem. This study compares the MDS method to the conventional method in the aspect of rock fracturing effect. The comparison is made by numerical simulations for a two-row bench blasting model in the LS-DYNA. The SPH-FEM coupling method is utilized for constructing the blasting model. The SPH elements are used for the rock in the near-field region of the blast holes, and the FEM elements for that in the far-field region. The RHT material model is used for the rock. As a result of the simulations, it was found that up to 0.4 m deeper damaged zone was appeared in the SMDS method than in the conventional method for the case of the burden 1.6 m and bench height 3.0 m. In addition, the fly-rock velocity to the normal direction of the bench slope was appeared about 2.0 m/s lower in the MMDS method compared to the other methods.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.29-29
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.275-275
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• 2022

One of the most widely grown food crops in the world, wheat, is increasing more lodged since for increased rains and winds caused by abnormal climate. During the Green Revolution, shorter wheat cultivars were bred using many Rht genes to increase lodging resistance. However, since only some Rht genes were used for breeding shorter wheat, it may have had a limited impact on wheat breeding and reduced genetic diversity. Therefore, it is essential to search for genes that have breeding potential and affect dwarfism in order to increase the genetic diversity of dwarf characteristics in wheat. In this study, we performed the RNA-seq between 'Keumkang' and 'Komac 5' ('Keumkang' mutant) to analyze the difference in plant height. Differentially expressed genes (DEGs) analysis and Gene function annotation were performed using 265,365,558 mapped reads. Cluster set analysis was performed to compress and select candidate gene DEGs affecting plant height, stem and internode. Gene expression analysis was performed in order to identify the functions of the selected genes by condensing the results of the DEG analysis into a cluster set analysis. This analysis of these plant height-related genes could help reduce plant height, improve lodging resistance, and increase wheat yield. Its application to wheat breeding will also affect the increased genetic diversity of wheat dwarfism.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.11a
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• pp.105-105
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• 2020