• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3700-3708
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• 2023

The stochastic origin ensembles method with resolution recovery (SOE-RR) has been proposed to reconstruct proton-induced prompt gammas (PGs), and the reconstructed PG image was used for range verification. However, due to low detection efficiency, the number of valid events is low. Such a low-count condition can degrade the accuracy of the SOE-RR method for proton range verification. In this study, we proposed two strategies to improve the reconstruction of the SOE-RR algorithm for low-count PG imaging. We also studied the number of iterations and repetitions required to achieve reliable range verification. We simulated a proton beam (10⁸ protons) irradiated on a water phantom and used a two-layer Compton camera to detect 4.44-MeV PGs. Our simulated results show that combining the SOE-RR algorithm with restricted volume (SOE-RR-RV) can reduce the error of the estimation of the Bragg peak position from 5.0 mm to 2.5 mm. We also found that the SOE-RR-RV algorithm initialized using a back-projection image could improve the convergence rate while maintaining accurate range verification. Finally, we observed that the improved SOE-RR algorithm set for 60,000 iterations and 25 repetitions could provide reliable PG images. Based on the proposed reconstruction strategies, the SOE-RR algorithm has the potential to achieve a positioning error of 2.5 mm for low-count PG imaging.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.54-61
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• 1994

This study was carried out to investigate the degree of contamination in private-drinking water supply (PDWS) and simple-piped water supply (SPWS), and to compare of water quality between them for 3 years from 1990 to 1992. The results of the study were as follows: 1. Private-drinking water supply (PDWS) (1) Field-Site (ㄱ) The items which were very significantly over the criteria (p<0.01), were temp., pH, NO-N, standard plate count (S.P.C.) and Coliform. (ㄴ) No. of households which were over the criteria, were 11.2~51.7% in temp., pH, NH$_3$-N and NO$_2$-N, and 83.1~93.3% in NO-N, S.P.C. and Coliform. (2) Moutain-Site (ㄱ) The items which were over the criteria, were NO$_2$-N (p<0.05), S.P.C. (p<0.01) and Coliform (p<0.01). (ㄴ) No. of households which were over the criteria, were 33.6 ~ 75.6% in NO$_2$-N, S.P.C. and Coliform. (3) No. of households which were fit to the criteria of all items, were 9.0% in field-site and 14.1% in mountain-site. 2. Simple-piped water supply (SPWS) (1) The items which were very significantly over the critera (p<0.01), were standard plate count (S.P.C.) and Coliform. (2) The water qualities of adjacent and remote samples were better than those of source samples. (3) Residual chloride was not detected in any sample. In conclusion, rural community requires to be continually performed the policy of safety drinking water supply, and to be devised an epoch-making counterplan for the level-up of simple-piped water supply (SPWS), espically on the method of disinfection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4404-4410
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• 2010

The purpose of this study is to find out the optimal mixing ratios of three different amount of red ginseng powder(0, 5, 10%), water(12, 16, 20%) and sugar(4, 8, 12%) per weight of glutinous rice powder. The microbial count increased with increasing moisture content. The microbial count has decreased in 10% addition group though the microbial count according to the red ginseng powder addition did not have a difference the having mind in 5% addition group. Control group(the red ginseng powder no addition) showed an exponential increase in the change in hardness according to the amount of the red ginseng powder addition 24 hours after(except the moisture addition amount 20%). However, the change in devotion hardly appeared without the relation in moisture and the amount of the sugar addition in the addition group of the red ginseng powder 5%. Moreover, the change in hardness besides the moisture addition amount 12% hardly appeared also in the addition group of the red ginseng powder 10%. It has been understood that the red ginseng powder addition 5% crowd smells, and the taste and the color are suitable though it was clarified to the red ginseng powder addition 10% crowd that a peculiar smell taste and taste to the red ginseng are very strong by the sensory inspection. In conclusion, according to its microbial count, texture and sensory analyses, the optimal Injulmi formulation consisted of red ginseng powder, water and sugar were 5, 16 and 8%. The results suggested that red ginseng powder is effective in increasing the self life of Injulmi.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.361-367
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• 1999

It was reported that green tea extract has antioxidant and antimicrobial activities. To improve the quality of seasoned squid, green tea water extract was sprayed on seasoned squid (water content 25%) and water content was adjusted to 27% and 29%. During storage at $30^{\circ}C$, TBA value, total plate count, browning were analyzed. Browning were analysed by 3 different method (absorbance of water solubilized color, 5% KOH-methanol solubilized color and color difference meter). Water and 5% KOH-methanol solubilized color showed good correlation, but color index detected by color difference meter was not. Green tea water extract slowed TBA value increment and reduced total plate count, so it was supposed that green tea water extract acts positively in manufacturing seasoned squid.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.86-90
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• 2012

Purpose: Quantification of myocardial blood flow (MBF) using dynamic PET imaging has the potential to assess coronary artery disease. Rb-82 plays a key role in the clinical assessment of myocardial perfusion using PET. However, MBF could be overestimated due to the underestimation of left ventricular input function in the beginning of the acquisition when the scanner has non-linearity between count rate and activity concentration due to the scanner dead-time. Therefore, in this study, we evaluated the count rate linearity as a function of the activity concentration in PET data acquired in list mode. Materials & methods: A cylindrical phantom (diameter, 12 cm length, 10.5 cm) filled with 296 MBq F-18 solution and 800 mL of water was used to estimate the linearity of the Biograph 40 True Point PET/CT scanner. PET data was acquired with 10 min per frame of 1 bed duration in list mode for different activity concentration levels in 7 half-lives. The images were reconstructed by OSEM and FBP algorithms. Prompt, net true and random counts of PET data according to the activity concentration were measured. Total and background counts were measured by drawing ROI on the phantom images and linearity was measured using background correction. Results: The prompt count rates in list mode were linearly increased proportionally to the activity concentration. At a low activity concentration (<30 kBq/mL), the prompt net true and random count rates were increased with the activity concentration. At a high activity concentration (>30 kBq/mL), the increasing rate of the prompt net true rates was slightly decreased while the increasing rate of random counts was increased. There was no difference in the image intensity linearity between OSEM and FBP algorithms. Conclusion: The Biograph 40 True Point PET/CT scanner showed good linearity of count rate even at a high activity concentration (~370 kBq/mL).The result indicates that the scanner is useful for the quantitative analysis of data in heart dynamic studies using Rb-82, N-13, O-15 and F-18.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.3
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• pp.332-340
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• 2013

The aim of this study was to investigate the quality characteristics of makgeolli that was produced by using different percentages (control, 3%, 5%, 7%, 9% by rice weight) of Angelica gigas Nakai water extracts during fermentation at $25^{\circ}C$ for 7 days. Yeast cell count in makgeolli steadily increased and showed the highest value at day 4 of fermentation, since then, the count decreased consistently. The final alcohol contents were higher than 15% in all samples. Soluble contents and antioxidation activity were significantly increased in percentage as Angelica water extracts increased (p<0.05). As the amount of Angelica water extracts increased, total polyphenol contents increased as well. Soluble contents and total polyphenol contents were increased according to the fermentation period. Total acidity increased up to day 3, but slowly decreased afterwards. However, the pH rapidly decreased by day 3, but then increased steadily. Reducing sugar amount was increased sharply by day 2 of fermentation and then, diminished gradually. Hunter's color value was not significantly different among samples however, they were significantly different between day 2 samples of fermentation and day 3 or more samples (p<0.05). In sensory evaluations, the sample produced using 5% Angelica water extracts received the highest score in herbal flavor, herbal taste, sourness, sweetness, and overall acceptance. Makgeolli using Angelica gigas Nakai water extracts showed excellent characteristics in antioxidative activity and higher total polyphenol content. Makgeolli produced using 5% Angelica water extracts received the highest score in sensory evaluation. Therefore, makgeolli produced using 5% Angelica water extracts was considered to be the most suitable for manufacturing makgeolli.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.57-69
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• 2024

Purpose: Quantitative analysis through count measurement in nuclear medicine planar images is limited by analysis techniques that are useful for obtaining various clinical information or by organ overlap or artifacts in actual clinical practice. On the other hand, the use of SPECT tomography images is quantitative analysis using volume rather than planar, which is not only free from problems such as projection overlap, but also has excellent quantitative accuracy. In the use of developing SPECT quantitative analysis technology, this study aims to compare the accuracy of quantitative analysis between ROI of the conventional planar images and VOI of the SPECT tomographic images in evaluating the count change happened by the volume change of the source. Materials and Methods: A ^99mTcO₄^- source(200.17 MBq) was filled with sterilized water in the syringe to create a phantom with an inner diameter volume of 60 cc, and a planar image and a SPECT image were obtained by reducing the volume by 15 cc (25%) respectively. ROI and VOI(threshold: 1~45%, 5% interval) were set for each image obtained to estimate true count and measure the total count, and compared with the preseted volumetric change rate(%). Results: When volume changes of 25%, 50%, and 75% occurred in the initial volume of 60 cc(100%) of the phantom, the average count changes of the measured planar image were 26.8%, 53.2%, 77.5%, and the average count changes of the SPECT image were 24.4%, 50.9%, and 76.8%. In this case, the VOI size(cm³) set showed an average change rate of 25.4%, 51.1%, and 76.6%. The highest threshold value for the accuracy of radioactive concentration by VOI size (average error -1.03%) was 35%, and the VOI size of the same threshold had an error of -17.1% on average compared to the actual volume. Conclusion: On average, the count-based volumetric change rate in nuclear medicine images was able to track changes more accurately using VOI than ROI, but there was no significant difference with relatively similar value. However, the accuracy of radioactive concentration according to individual VOI sizes did not match, but it is considered that a relatively accurate quantitative analysis can be expected when the size of VOI is set smaller than the actual volume.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.381-385
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• 2005

Characterization of particle behavior is becoming more important in performance evaluation of water treatment system as well as in operation of the system because conventional parameter, turbidity has lack of explaining ability on small sized microorganisms such like Cryptosporidium etc. Accordingly, particle counter has been introduced in evaluation and operation of the treatment system. However researches on the relationship between turbidity, particle count and/or different sand/anthracite sizes have not been concurrent. Therefore in this study, the relationship was investigated to improve performance evaluation of sand filter so as to help choosing sand/anthracite effective size as a design parameter of water treatment facility. According to the results, too small or too large effective size media filter reached to turbidity limit(0.1 NTU)earlier. However, because shallow sand layer may cause early breakthrough, the depth of sand layer should be provided enough in order to compromise water quality and productivity.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.142-144
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• 1979

To investigate the potability of water from rural area of Kyung-Gi-Do, the bacteriological examination of water samples from Yong-In Gun and Hwa-Sung Gun were carried out. The results obtained can be summarized as follows: 1. The total viable cell count showed great difference between the samples; 3 samples included less than $1{\times}10^2$ per ml and 6 samples more than $1{\times}10^4$ per ml. The maximum count arrived at $1{\times}10^5$ per ml. 2. The existence of faecal Streptococcus was confirmed in the samples of 4 areas. 3. For the potability, only one sample was remarked as positive and all the others were judged as negative or suspect.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.1
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• pp.19-25
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• 2023

Objective: Sleep deprivation (SD) is a common problem in today's stressful lifestyle and have physiological consequences, including reproductive dysfunction and infertility. As an antioxidant, olive oil may be effective in reducing testicular and spermatological damage by decreasing the production of free radicals. Methods: This study investigated the effects of olive oil on sperm quality and testicular structure using stereological methods to assess rats with SD. Results: When comparing SD group to grid floor+distilled water (GR) group, we found that the sperm count and motility, as well as the percentage of slow progressive sperm was significantly lower in SD group (p<0.05), but the percentage of immotile sperm was higher (p<0.01). However, no improvement was observed in sperm count or motility after concomitant treatment of SD group with olive oil. Stereological examinations revealed no significant change in the total volumes of the seminiferous tubules, interstitial tissue, and germinal epithelium in the study groups. Conversely, the total number of testicular cell types was significantly lower in SD group than in GR group. Although the total number of Sertoli and Leydig cells was significantly higher in the S +olive oil group than in the untreated SD group, no significant difference in the total number of other testicular cell types was observed between the two groups. Conclusion: SD potentially induced structural changes in testis that affected sperm count and motility. However, olive oil only improved the total number of Sertoli and Leydig cells in the animals with SD and did not improve sperm count and motility.