• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.51-56
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• 2015

Purpose As medical radiation exposures on patients are being social issues an interest in a relief of radiation exposures on patients is increasing. Further, there are many cases where some patients among who are getting PET/CT tests choose to get implanted with metal artifacts in their bodies. This study is to find out effects of presence or absence of metal artifacts when dose change or CT attenuation correction for the relief of radiation exposures are applied using phantoms through changes in standard uptake value (SUV). Materials and Methods GE company's Discovery 710 machine was used for PET/CT test equipments. We used NEMA IEC body phantoms. We also used screw and mesh cage made of titanium which are used in real clinical processes for the metal artifacts. Two experiments were conducted: One is to test and measure repeatedly about SUV about differences in CT attenuation corrections according to dose changes and another is to do the same procedure for SUV about the presence and absence of the metal artifacts. We injected $^{18}F-FDG$ into NEMA IEC body phantoms with a TBR ratio of 4:1 and then put the metal material into the transformation phantoms. Once a scanning for the metal artifacts was done we eliminated the metal artifacts and went on non-metal artifacts. For the each two experiments, we scanned repeatedly with CT kVp (140, 120, 100, 80) and mA (120, 80, 40, 20, 10) for an experimental condition. For PET, we reconstructed each with standard AC (STD) technique and quantitation achieved cnsistently QAC) technique among CT attenuation correction methods. We conducted a comparative analysis on measured average values and variations which were measured through repeated measure of SUV of region 1, 2, 3 spheres for each conditions of non-metal /metal scan. Results For each kVp, 120, 80, 40 (mA) of non/metal (screw, mesh cage) showed low frequency of fluctuation rates of above 2%. In 20, 10 mA above 2% of fluctuation rates appeared in high frequency. Also, when we compared the fluctuation rates of STD and QAC techniques in non/metal (screw, mesh cage) tests QAC technique showed about 1-10% of differences for each conditions compared to STD technique. In addition, metal types did not have significant effects on fluctuation rates. Conclusion We confirmed that SUV fluctuation rates for both STD and QAC techniques increase as dosage is lower. We also found that the SUV of PET data was maintained steadily in a low dosage for QAC technique when compared with STD technique. Hence, when the low dosage is used for the relief of radiation exposures on patients QAC technique may be exploited helpfully and this could be applied in the same way for patients with metal artifacts implanted in their bodies.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.457-468
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• 2014

This study was conducted to investigate the effect of mixed-sowing of legume forage and applying of cattle manure on the productivity of rye in order to produce the organic roughage to be effectively reducing the environmental contamination and to provide Hanwoo rearing farmer with safe organic animal products. The present study also aimed to evaluate optimal applying level of cattle manure and carrying capacity of Korean native cattle (Hanwoo) per unit area. The annual amount of crude protein (CP) of rye in Gyeongju were higher than those of in Gyeongsan and Yeongju, and the mixed-sowing of forage pea was the highest (p<0.05) compared with the single-sowing. The amount of CP were increased proportionately corresponded to the applying level of fermented cattle manure, and found significantly (p<0.05) high at the level of 100 and 150 kg/ha groups. With feed value of forage, CP was tended to be higher in the mixed-sowing of legume than the single-sowing of rye at the wintering experimental sites of legume, and in particular the forage peas was higher (p<0.05) than other crops. Carrying capacity of organic Hanwoo (head/ha) was higher (p<0.05) in Gyeongju (3.28 head) than that in Gyeongsan (1.94) and Yeongju (1.50). The carrying capacity in the single-sowing of rye also was lower than that in the mixed-sowing of legume, and the forage peas was the highest among the mixed-sowing groups (p<0.05). Overall, the present results showed that it would be recommended to take into account the wintering for mix-sowing of legume. The fermented cattle manure may be applied for legume in the wintering unavailable regions. In addition, the applying the fermented cattle manure at the level of 100~150kg/ha and the mix-sowing of legume with forage peas may increase the productivity per unit area and feed value including CP for improving carrying capacity of organic Hanwoo.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.52-59
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• 2014

This study was conducted to estimate the Hanwoo carrying capacity when whole crop wheat, as a winter forage crop, was grown on mixed-sowing of legume forage and by applying cattle manure on the productivity and feed value of whole crop wheat during the period of 2012~2013. The experiment was conducted in a split plot design with three replications. The main plots consisted of three different culture methods such as whole crop wheat and mixed sowing combination with hairy vetch or forage pea. The subplots consisted of four different applications of cattle manure (0, 50, 100 and 150 kg N/ha). The annual amount of dry matter (DM) of whole crop wheat in Gyeongju were higher than those of in Gyeongsan and Yeongju, and the mixed-sowing of hairy vetch mixture was the highest (p<0.05) compared with the single-sowing of whole crop wheat and mixed-sowing of legume in Gyeongju. The DM amounts were increased proportionately corresponded to the applying level of cattle manure, and was found to be significantly (p<0.05) high at the level of 100 and 150 kg/ha groups. With the feed value of forage, the crude protein (CP) contents tended to be higher in the mixed-sowing of legume than the single-sowing of whole crop wheat at the wintering experimental sites of legume. For whole crop wheat, total digestible nutrients (TDN) content was the highest in the mixed sowing plots of forage pea in Gyeongsan; however, there was no significant differences among the single-sowing of whole crop wheat. The carrying capacity of Hanwoo (head/ha) was higher (p<0.05) in Gyeongju (3.83 head) than that in Gyeongsan (3.11) and Yeongju (1.35). Further, the carrying capacity in the single-sowing of whole crop wheat was lower than that in the mixed-sowing of legume, and the hairy vetch was the highest among the mixed-sowing groups (p<0.05). Overall, the present results recommend taking into account the wintering for the mix-sowing of legume in Gyeongbuk province. The cattle manure may be applied for legume in the wintering unavailable regions. In addition, applying cattle manure at the level of 100~150 kg/ha and the mix-sowing of legume may increase the productivity per unit area and feed value, including the CP, for improving the carrying capacity of Hanwoo.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.74-84
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• 1998

A doubly resonant ultrasonic transducer has been designed as an attempt to increase the bandwidth of underwater transducers. The dual resonance conditions were accomplished by attaching a single acoustic matching layer on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and a prestress bolt. A modified Mason's model was used for the performance analysis and the design of transducers, and the constructed transducers were tested experimentally and numerically by changing the impedances and thicknesses of the head, tail and matching layers in the water tank. Two distinct resonance peaks in the transmitting voltage response(TVR) of a developed transducer were observed at 34.3 and 40.4 kHz, respectively, with the difference frequency of 6.1kHz and the center frequency of 37.2kHz. The values of TVR at these frequencies were 136.5 dB re $1\;\muPa/V$ at 34.3 kHz and 136.8 dB re $1\;\muPa/V$ at 40.4 kHz, respectively. Reasonable agreement between the experimental results and the numerical results was achieved. From this result, it is expected that the generation of the distinct resonances at any two desired frequencies can be achieved through the proper choice of the matching layer to provide the impedance transformation between the transducer and the medium.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.85-95
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• 1998

The broadband ultrasonic transducers have been designed to use in obtaining the broadband echo signals from fish schools in relation to the identification of fish species. The broadening of bandwidth was achieved by attaching double acoustic matching layers on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and to evaluate the performance characteristics, such as the transmitting voltage response(TVR) of transducers. The constructed transducers were tested experimentally and numerically by changing the parameters such as impedances and thicknesses of the head, tail and matching layers, in the water tank. Also, the developed transducer was excited by a chirp signal and the received chirp waveforms were analyzed. According to the measured TVR results, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 7 mm thick and a polyurethane window of 18 mm thick was 7.3 kHz with a center frequency of 38.8 kHz, and the maximum and the minimum values of the TVR in this frequency region were 135.7 dB and 132.7 dB re $1\;{\mu}Pa/V$ at 1 m, respectively. Also, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 11 mm thick and a polyurethane window of 15 mm thick was 6.2 kHz with a center frequency of 38.6 kHz, and the maximum TVR value in the frequency region was 136.3 dB re $1\;{\mu}Pa/V$ at 1 m. Reasonable agreement between the experimental results and the numerical results for the TVR of the developed transducers was achieved. The frequency dependant characteristics of experimentally observed chirp signals closely matched to the measured TVR results. These results suggest that there is potential for increasing the bandwidth by varying other parameters in the transducer design and the material of the acoustic matching layers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.386-395
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• 2016

To develop a functional fermentation food from Rubus coreanus Miquel (Bokbunja) and chlorella mixtures, optimal lactic acid fermentation conditions were established, and quality properties based on physicochemical evaluation such as chemical compositions, free sugars, organic acids, and antibacterial activities were investigated. Regarding optimal fermentation strain selection, formation of lactic acid was best in Lactobacillus plantarum among the experimental strains (10 kinds), and the optimal fermentation temperature was $37^{\circ}C$. In addition, overall acceptability in the sensory evaluation was highest in the 5% chlorella mixture sample. Therefore, quality properties of the prepared sample under the established optimal fermentation conditions were investigated. Moisture, total sugar (dry basis), crude fiber (dry basis), and pH of fermented Rubus coreanus Miquel juice (RCM) with 5% chlorella mixture (RCM-C5) were reduced by 4.90%, 14.15%, and 0.32%, respectively, as compared with non-fermented RCM. Meanwhile, crude protein, crude fat, and crude ash (dry basis) of RCM-C5 were elevated by 13.75%, 0.18%, and 0.73%, respectively, as compared with RCM. The yellowness (b value) of color values was greater in RCM-C5 compared to RCM. The free sugar and organic acid contents of RCM-C5 were elevated by 0.97% and 616.30 mg%, respectively, as compared with RCM. In addition, the gram positive bacterium Staphylococcus aureus was elevated by 5.83% while gram negative bacteria Escherichia coli and Salmonella Typhimurium were elevated by 2.94% and 4.67%, respectively, as compared with RCM. In conclusion, the quality properties of RCM and chlorella lactic acid fermentation mixtures were improved compared with the general RCM product. Consequently, it is possible to apply fermented RCM as a functional fermentation food.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.131-138
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• 1987

Experimental informations on the possible alternative resources of soil addition in sandy paddy soils were obtained by applying fertilizer N, P, and K to the top of 26 cm long columns containing the soil-ameliorator mixture and by determining the concentration and leaching loss of nutrients in percolated water and permeability. 1. Addition of red earth and compost to soils decreased pronouncedly the permeability. Relative magnitude of permeability was compost+slag+red earth > compost+red earth > compost > red earth > compost+slag > slag > non-added soil. 2. Concentration and leaching loss of $NH_4-N$ and $SiO_2$ were high by addition of compost-slag or red earth mixture to soils. The present of these nutrients in soils after experiment was, also, higher than that in non-added soil and in red earth to soils. 3. Those of K, Ca, and Mg were similar to $NH_4-N$ and $SiO_2$. Especially, leaching loss and present of K in soils by addition of compost to soils were higher dramatically than those of non-added soil and of red earth to soils. 4. Those of $Fe^{{+}{+}}$ in non-added soil were much higher than those by addition of compost and slag to soils. These values were the highest in 12 days after submergence, while these of $Mn^{{+}{+}}$ the lowest. 5. Concentration of $NH_4-N$ was high by addition of compost to soils, while the present of it in soils after experiment was tended to be contrary.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.280-289
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• 2018

Purpose: The purpose of this randomized clinical trial is to determine whether implant length and the crown-to-implant (C/I) ratio influence implant stability and peri-implant marginal bone loss (MBL). Materials and Methods: 46 patients with single tooth missing in the posterior molar region of the mandible were included in this study. 19 implants (CMI IS-III $active^{(R)}$ long implant) of 5.0 mm diameter and 10 mm length were installed for the control group, while 27 implants (CMI IS-III $active^{(R)}$ short implant) of 5.5 mm diameter and 6.6, 7.3 or 8.5 mm length were placed for the experimental group. Each implant was inserted and immediately loaded using the digitally pre-fabricated surgical template and provisional restoration. The CAD-CAM monolithic zirconia crown was fabricated at 3 months after the surgery as a definitive restoration. The ISQ value and the MBL was measured at 48 weeks after the surgery. The correlation between the C/I ratio, MBL, and secondary implant stability was analyzed. Results: Successful results in terms of ISQ and MBL were achieved with both groups. There was no significant difference between the groups in terms of ISQ values and MBL at 48 weeks after the surgery (P > 0.05). No significant correlation was found between the C/I ratio and secondary stability as well as the C/I ratio and the MBL (P > 0.05). Conclusion: The influence of C/I ratio in both groups was not shown on the stability nor the marginal bone loss in implants supporting single crown of the mandible. Short implant could be a preferable alternative option in the reduced bone height mandible under the limited condition despite its higher C/I ratio.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.95-103
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• 2019

Temperature and relative humidity are important factors in crop cultivation and should be properly controlled for improving crop yield and quality. In order to control the environment accurately, we need to predict how the environment will change in the future. The objective of this study was to predict air temperature and relative humidity at a future time by using a multilayer perceptron (MLP). The data required to train MLP was collected every 10 min from Oct. 1, 2016 to Feb. 28, 2018 in an eight-span greenhouse ($1,032m^2$) cultivating mango (Mangifera indica cv. Irwin). The inputs for the MLP were greenhouse inside and outside environment data, and set-up and operating values of environment control devices. By using these data, the MLP was trained to predict the air temperature and relative humidity at a future time of 10 to 120 min. Considering typical four seasons in Korea, three-day data of the each season were compared as test data. The MLP was optimized with four hidden layers and 128 nodes for air temperature ($R^2=0.988$) and with four hidden layers and 64 nodes for relative humidity ($R^2=0.990$). Due to the characteristics of MLP, the accuracy decreased as the prediction time became longer. However, air temperature and relative humidity were properly predicted regardless of the environmental changes varied from season to season. For specific data such as spray irrigation, however, the numbers of trained data were too small, resulting in poor predictive accuracy. In this study, air temperature and relative humidity were appropriately predicted through optimization of MLP, but were limited to the experimental greenhouse. Therefore, it is necessary to collect more data from greenhouses at various places and modify the structure of neural network for generalization.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.145-159
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• 2021

is a contemporary experimental film that forms ambiguity in the narrative and the psychological motivation of the characters, destroys linear temporality, and reminds of manipulation possibilities in digital images through varied techniques, and it carries implication by the fact that the transformation process of human subjects and self-awareness are connected to social trauma and makes way to infer by comparing it to the historical contexts of other nations or societies. centers on the space outside the screen, absent space, and the intrinsic meaning within the space and the frame and shares the information in the visible space and the space outside the screen and arouses an active perceptual process so that the audience can deduce the information that is not presented. The film visualized the historical meaning without describing the background of the times in detail and aimed to express the conflicts and worries between the god, a transcendental existence, with humans, which are marginal beings, within the conflicting structure among humans. Moreover, attempted to resolve the sadness of loss and absence through the spatial aesthetics and the film presented the progression of the situation through the contrast of the characters and also the comparison between light and darkness. This study intends to make an attempt of interpreting the realm involving personal (characters) stories and the social and historical backgrounds together with the religious sphere and discuss the visualization of the semantic context. In addition, this study analyzed the sequence of the scenes in , which reconstructs identity and historical cases and religious values to observe the meaning and characteristics and closely analyze the general meaning pursued by the film. discussed the issues of trauma that individuals, regions, and nations confront as a representation and interpretation of the trauma connoted in the film, and consideration can be provided about the implication concerning the situation and context in South Korea. Furthermore, the film placidly discusses the growth and agony in humans and the society without expressing it excessively, so it will be a valuable research result to inspire the trend of creating films that incorporate new imaging technology and original visualization techniques.