• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.4
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• pp.81-88
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• 2001

This experiment was carried out to evaluate the effect of residual food compost application on plant growth and physicochemical properties of soil when residual food compost made from the composting process as part of organic waste recycling was applied in soil as variable rate. The treatments were composed non-fertilizer treatment, control treatment applied with pig compost $20Mg(D.W.)ha^{-1}$, and residual food compost treatments each of applied with 20, 40, 60, $80Mg(D.W.)ha^{-1}$ and were randomized complete block design with three replication. Soil pH after experiment was more increased as more increase application of residual food compost. Other chemical properties of soil including EC were also showed the similar results. The plant growth in treatments applied much of residual food compost at the early growth stage was very damaged and these results were proved at the first growth measurement. Production of the red pepper especially reduced in treatments taken growth demage at the early stage and that of $20Mgha^{-1}$ treatment almost same as control treatment. Bulk density was reduced but porosity was increased according to increase of residual food compost application. Considering the reduction of red pepper production and the demage of growth at the early stage by plenty of salt and water soluble application volume of residual food compost was not permitted over of $30Mgha^{-1}$. Additively, to settle the application volume of residual food compost and to evaluate the plant growth and changes of physicochemical properties of soil, the results taken from continual applying is concluded more important than single application.

• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.399-408
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• 2001

Tooth bleaching has been prevailing recently for its ability to recover the color and shape of natural teeth without reduction of tooth material. However, it has been reported that bleaching procedure adversely affects the adhesive bond strength of composite resin to tooth. At the same time the bond strength was reported to be regained by application of some chemical agents. The purpose of this in vitro study was to investigate the effect of the removal of residual peroxide on the composite- enamel adhesion and also evaluated fracture mode between resin and enamel after bleaching. Sixty extracted human anterior and premolars teeth were divided into 5 groups and bleached by combined technique using of office bleaching with 35 % hydrogen peroxide and matrix bleaching with 10% carbamide peroxide for 4 weeks. After bleaching, the labial surfaces of each tooth were treated with catalase, 70% ethyl alcohol, distilled water and filled with composite resin. Shear bond strength was tested and the fractured surfaces were also examined with SEM. Analysis revealed significantly higher bond strength values. (p＜0.05) for catalase-treated specimens, but water-treated specimens showed reduction of bond strength, alcohol- treated specimens had medium value between the two groups(p＜0.05). The fracture mode was shown that the catalase group and the alcohol group had cohesive failure but the water sprayed group had adhesive failure. It was concluded that the peroxide residues in tooth after bleaching seems to be removed by gradual diffusion and the free radical oxygen from peroxide prevents polymerization by combining catalyst in the resin monomer. Therefore it may be possible to eliminate the adverse effect on the adhesion of composite resin to enamel after bleaching by using water displacement solution or dentin bonding agent including it for effective removal of residual peroxide.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.302-307
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• 2012

This study was carried out to elucidate residual characteristics of environment friendly agricultural material rotenone in chilli pepper and calculate processing factors by drying. The test material was sprayed twice onto chilli peppers at an interval of seven days and then the chilli peppers were harvested at 0, 1, 3, 5 and 7 days after final spray. Limits of quantitation (LOQs) of rotenone in fresh and dried chilli peppers were 0.03 and 0.07 mg/kg, respectively. Recoveries of the test material in fresh and dried chilli peppers ranged from 89.52 to 97.86% and from 85.76 to 91.61%, respectively. As a results of residual material analysis, amounts of rotenone in fresh and dried chilli peppers ranged from 0.03 to 0.39 mg/kg and from 0.07 to 0.75 mg/kg, respectively, representing that the residual amounts of rotenone decreased time-coursely. Processing factors of rotenone in fresh chilli pepper by drying were found to be from 2.03 to 3.13, indicating that the residual concentration of rotenone in dried chilli pepper increased from two to three times by drying. However, the reduction factor of rotenone in fresh chilli pepper by drying ranged from 0.38 to 0.59, representing that some of rotenone in fresh chilli pepper disappeared during the drying process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.1
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• pp.79-83
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• 2010

The conventional welding technique such as shield metal arc welding has been mostly applied to the piping system of the nuclear power plants. It is well known that this welding technique causes the overheating and welding defects due to the large groove angle of weld. On the other hand, the narrow gap welding(NGW) technique has many merits, for instance, the reduction of welding time, the shrinkage of weld and the small deformation of the weld due to the small groove angle and welding bead width comparing with the conventional welds. These characteristics of NGW affect the deformation behavior and the distribution of welding residual stress of NGW, thus it is believed that the residual stress results obtained from conventional welding procedure may not be applied to structural integrity evaluation of NGW. In this paper, the welding residual stress of NGW was predicted using the nonlinear finite element analysis to simulate the thermal and mechanical effects of the NGW. The present results can be used as the important information to perform the flaw evaluation and to improve the weld procedure of NGW.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.426-434
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• 2010

This study is experimentally performed to evaluate the strength reduction behavior and its statistical properties of plain woven glass/epoxy composites. The results indicate that the major impact damage of plain woven glass/epoxy composites is the fiber breakage and matrix crack, whereas the dominant impact damage of unidirectional carbon/epoxy laminates is the delamination, which depends on the stacking sequence. The residual strength prediction models, previously proposed on unidirectional laminates, are applied to evaluate the residual strength of plain woven glass/epoxy composites with impact damage. Among these models, the results by Caprino and Avva's model have a good agreement with the experimental results. To investigate the variability of residual strength of the impacted composite materials, a statistical model was proposed and its results were in conformance with the experimental results regardless of their thickness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2480-2496
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• 2020

Considering that high-dose X-ray radiation during CT scans may bring potential risks to patients, in the medical imaging industry there has been increasing emphasis on low-dose CT. Due to complex statistical characteristics of noise found in low-dose CT images, many traditional methods are difficult to preserve structural details effectively while suppressing noise and artifacts. Inspired by the deep learning techniques, we propose a densely connected residual network (DCRN) for low-dose CT image noise cancelation, which combines the ideas of dense connection with residual learning. On one hand, dense connection maximizes information flow between layers in the network, which is beneficial to maintain structural details when denoising images. On the other hand, residual learning paired with batch normalization would allow for decreased training speed and better noise reduction performance in images. The experiments are performed on the 100 CT images selected from a public medical dataset-TCIA(The Cancer Imaging Archive). Compared with the other three competitive denoising algorithms, both subjective visual effect and objective evaluation indexes which include PSNR, RMSE, MAE and SSIM show that the proposed network can improve LDCT images quality more effectively while maintaining a low computational cost. In the objective evaluation indexes, the highest PSNR 33.67, RMSE 5.659, MAE 1.965 and SSIM 0.9434 are achieved by the proposed method. Especially for RMSE, compare with the best performing algorithm in the comparison algorithms, the proposed network increases it by 7 percentage points.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.537-542
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• 2011

The thermo-mechanical interaction between brake block and wheel tread during braking has been found to cause thermal crack on the wheel tread. Due to thermal expansion of the rim material, the thermal cracks will protrude from the wheel tread and be more exposed to wear during the wheel/block contact than the rest of the tread surface. The wheel rim is in residual compression stress when is new. After service running, the region in the tread has reversed to tension. This condition can lead to the formation and growth of thermal cracks in the rim which can ultimately lead to premature failure of wheel. In the present paper, the thermal cracks of railway wheel, one of severe damages on the wheel tread, were evaluated to understand the safety of railway wheel in running condition. The residual stresses for damaged wheel which are applied to tread brake are investigated. Mainly X-ray diffusion method is used. Under the condition of concurrent loading of continuous rolling contact with rails and cyclic frictional heat from brake blocks, the reduction of residual stress is found to correlate well with the thermal crack initiation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.353-360
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• 2010

The Kyunggi Bay in mid-west of Korea is a relatively large estuarine system that connects the Han River system with Yellow Sea. Due to macro-tidal range of more than 8 m, the urban estuary shows deep tidal channels and wide tidal flats. Since last 30 years, the coastal development is undergoing, yielding noticeable change in environment. Particularly the tidal flat dynamics are generally accepted as being related with tidal residual flows in this area (Kim et al., 2009). We have estimated the annual variation and vertical structure of residual currents with one-year long observed flows in two major tidal channels of Kyunggi Bay. The moving average method and tidal current harmonic analysis yield nearly the same results on residual flow. The residual flow in Jangbong channel ranges from 20 cm/s in summer to 30 cm/s in winter. It is noticeable that the residual flow in Jangbong channel is flood dominant throughout the year, while the flow in Seokmo channel is ebb-dominant residual flow with current speed range of 20-40 cm/s. Due to the baroclinic response of relatively shallow estuary, significant reduction of energy in bottom layers have been observed, indicating the importance of residual circulation to the tidal flat behavior.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.258-265
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• 2023

After application of veterinary antibiotics, they may be partially metabolized before they are excreted by feces or urine either as unaltered form or as metabolites. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based compost and liquid fertilizer on farmlands and lead to secondary pollution. The objective of this study was to compare the residual concentrations of 6 veterinary antibiotics by different production stages of liquid fertilizer from livestock manure recycling facilities. The relationship between concentration change of the residual antibiotics and the amount of liquid fertilizer component was also assessed. Pre-treatment showed the recovery of 63.4-106.7% at ppb level and the limit of quantification of 0.009-0.037 ㎍/L.As the result of analyzing the relationship between the residual concentrations of antibiotics and the amount of N component in liquid fertilizer by different production stages, the residual concentrations of antibiotics and N tended to decrease as the stabilization period elapsed during the liquid fertilization process. Average concentrations of sulfamethazine in raw materials, middle and final products of liquid fertilizer were 40.85, 26.17, 3.54 ㎍/L, respectively. Those of chlortetracycline decreased from 2.32 to 1.25 ㎍/L. The other 4 antibiotics also showed a decreasing trend by different production stages of liquid fertilizer. The amount of liquid fertilizer component N decreased from 0.21 to 0.096% by production stages of liquid fertilizer. It is considered that the correlation between residual antibiotic concentrations and N content can be applied as basic data for setting antibiotic reduction indicators.

• The Journal of the Acoustical Society of Korea
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• v.26 no.3E
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• pp.87-96
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• 2007

In this paper we propose a new noise reduction algorithm for stationary and nonstationary noisy environments. Our algorithm classifies the speech and noise signal contributions in time-frequency bins, and is not based on a spectral algorithm or a minimum statistics approach. It relies on calculating the ratio of the standard deviation of the noisy power spectrum in time-frequency bins to its normalized time-frequency average. We show that good quality can be achieved for enhancement speech signal by choosing appropriate values for ${\delta}_t\;and\;{\delta}_f$. The proposed method greatly reduces the noise while providing enhanced speech with lower residual noise and somewhat higher mean opinion score (MOS), background intrusiveness (BAK) and signal distortion (SIG) scores than conventional methods.