• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.13-20
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• 2008

The flow rate measurements in a multi-phase flow pipeline were evaluated quantitatively by means of a clamp-on sealed radioisotope based on a cross correlation signal processing technique. The flow rates were calculated by a determination of the transit time between two sealed gamma sources by using a cross correlation function following FFT filtering, then corrected with vapor fraction in the pipeline which was measured by the ${\gamma}$-ray attenuation method. The pipeline model was manufactured by acrylic resin(ID. 8 cm, L=3.5 m, t=10 mm), and the multi-phase flow patterns were realized by an injection of compressed $N_2$ gas. Two sealed gamma sources of $^{137}Cs$ (E=0.662 MeV, ${\Gamma}$ $factor=0.326\;R{\cdot}h^{-1}{\cdot}m^2{\cdot}Ci^{-1}$) of 20 mCi and 17 mCi, and radiation detectors of $2"{\times}2"$ NaI(Tl) scintillation counter (Eberline, SP-3) were used for this study. Under the given conditions(the distance between two sources: 4D(D; inner diameter), N/S ratio: $0.12{\sim}0.15$, sampling time ${\Delta}t$: 4msec), the measured flow rates showed the maximum. relative error of 1.7 % when compared to the real ones through the vapor content corrections($6.1\;%{\sim}9.2\;%$). From a subsequent experiment, it was proven that the closer the distance between the two sealed sources is, the more precise the measured flow rates are. Provided additional studies related to the selection of radioisotopes their activity, and an optimization of the experimental geometry are carried out, it is anticipated that a radioisotope application for flow rate measurements can be used as an important tool for monitoring multi-phase facilities belonging to petrochemical and refinery industries and contributes economically in the light of maintenance and control of them.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.75-81
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• 2017

Purpose: To evaluate the reproducibility of image-guided radiotherapy using ultrasonography which is non-invasive, without radiation exposure for prostate cancer patients. Materials and Methods: We analyzed the setup variation of 1,105 images for 26 prostate cancer patients and the mean, standard deviation and 3D-error in AP, RL and SI directions. Setup variations were classified 0-1 mm, 1-3 mm, 3-5 mm, 5 mm and more. Results: The mean and standard deviation of setup variation in AP, RL and SI directions was $1.87{\pm}1.36mm$, $1.73{\pm}1.22mm$ and $2.01{\pm}1.40mm$. The 3D-error in AP, RL and SI directions was $3.63{\pm}1.63mm$. The frequency of setup variation in AP direction was 29 % in the range from 0 mm to 1 mm, 50.2 % in the range from 1 mm to 3 mm, 19.6 % in the range from 3 mm to 5 mm and 1.3 % in the range of 5 mm or more. In RL direction, the frequency was 31.3 % in the range from 0 mm to 1 mm, 52.5 % in the range from 1 mm to 3 mm, 15.8 % in the range from 3 mm to 5 mm and 0.5 % in the range of 5 mm or more. SI direction, the frequency of errors in the range from 0 mm to 1 mm was 26.3 %, 50.2 % in the range from 1 mm to 3 mm, 22.4 % in the range from 3 mm to 5 mm, and 1.1 % in the range of 5 mm or more. Conclusion: The setup error was highest in the SI direction of $2.01{\pm}1.40mm$. The frequency in each direction was the highest in more than 50 % in the range from 1 mm to 3 mm. $Clarity^{TM}$ Auto scan is possible to monitoring the motion of the prostate during the treatment and to repositioning the patient. In conclusion real-time image-guided radiotherapy using ultrasonography will be increase the reproducibility of radiation therapy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.510-517
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• 2016

This study was conducted to investigate the antioxidant and hepatoprotective effects of eriodictyol compound against hydrogen peroxide-induced oxidative stress in HepG2 cells by measuring expression levels of antioxidant enzymes, liver function index enzyme activities, and inhibitory effects against reactive oxygen species (ROS) production. HepG2 cell viability was assessed using 3-(4,5-dimethyl thiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. In the concentration range of $10{\sim}50{\mu}g/mL$, eriodictyol displayed over 98% cell viability in HepG2 cells. The effects of increased gene expression on hydrogen peroxide-induced oxidative stress were analyzed by monitoring antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx) gene expression levels using real-time PCR. Eriodictyol compound significantly increased gene expression levels of SOD, CAT, and GPx in a dose-dependent manner ($10{\sim}50{\mu}g/mL$). Hepatoprotective effects against hydrogen peroxide-induced oxidative stress were analyzed by monitoring glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) activities in HepG2 cell culture medium using a biochemistry analyzer. Eriodictyol compound significantly reduced GOT, LDH, and GGT activities in a dose-dependent manner in HepG2 cells. ROS level in HepG2 cells was analyzed by 2',7'-dichlorofluorescein fluorescence diacetate assay, and eriodictyol compound effectively reduced the intracellular ROS level in HepG2 cells. The results reveal that eriodictyol compound can be useful for development of effective antioxidant and hepatoprotective agents.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2159-2164
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• 2016

Background: A diagnosis of chronic myeloid leukemia (CML) is made on discovery of the presence of a Philadelphia (Ph) chromosome. The success of the treatment of this form of leukemia with tyrosine kinase inhibitor (TKI) is monitored by reduction of the Ph chromosome. Objective: To compare the role of conventional cytogenetic (CC) methods with a real time quantitative polymerase chain reaction (RQ-PCR) and fluorescence in situ hybridization (FISH) for diagnosis and treatment monitoring of CML patients. The secondary outcome was to analyze the treatment responses to TKI in CML patients. Materials and Methods: This was a retrospective study of CML patients who attended the Hematology clinic at Chiang Mai University Hospital from 2005-2010. Medical records were reviewed for demographic data, risk score, treatment response and the results of CC methods, FISH and RQ-PCR. Results: One hundred and twenty three cases were included in the study, 57.7% of whom were male with a mean age of 46.9 years. Most of the patients registered as intermediate to high risk on the Sokal score. At diagnosis, 121 patients were tested using the CC method and 118 (95.9%) were identified as positive. Five patients failed to be diagnosed by CC methods but were positive for BCR-ABL1 using the FISH method. Imatinib was the first-line treatment used in 120 patients (97.6%). In most patients (108 out of 122, 88.5%), a complete cytogenetic response (CCyR) was achieved after TKI therapy and in 86 patients (70.5%) CCyR was achieved long term by the CC method. Five out of the 35 analyzed patients in which CCyR was achieved by the CC method had a positive FISH result. Out of the 76 patients in which CCyR was achieved, RQ-PCR classified patients to only CCyR in 17 patients (22.4%) with a deeper major molecular response (MMR) in 4 patients (5.3%) and complete molecular response (CMR) in 55 patients (72.4%). In the case of initial therapy, CCyR was achieved in 95 patients (79.1%) who received imatinib and in both patients who received dasatinib (100%). For the second line treatment, nilotinib were used in 30 patients and in 19 of them (63.3%) CCyR was achieved. In half of the 6 patients (50%) who received dasatinib as second line or third line treatment CCyR was also achieved. Conclusions: CML patients had a good response to TKI treatment. FISH could be useful for diagnosis in cases where CC analysis failed to detect the Ph chromosome. RQ-PCR was helpful in detecting any residual disease and determining the depth of the treatment response at levels greater than the CC methods.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.26-36
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• 2020

This study aimed at investigating present research and knowledge-base on climate change adaptation in ecosystem sector and analyzed the current status of basic information on ecosystem that functions as evidence-base of climate change adaptation to deduce the suggestions for the future development for knowledge and information in biodiversity. In this perspective, a questionary survey titled as "the ecological knowledge-base and information needs for climate change adaptation" with the researchers who were engaged with adaptation studies for biodiversity in the ecosystem related-research institutes including national and 17 regional local governments-affiliated agencies in Korea. The results are as follows; current status of utilizing ecological information which supports climate change adaptation strategy, future needs for adaptation knowledge and ecological information, and activation of utilizing ecological information. The majority of respondents (90.7%) replied that the ecological information has high relevance when conducting research on climate change adaptation. However, only half of all respondents (53.2%) agreed with the real viability of current information to the adaptation research. Particularly, urgent priority for researchers was deduced as intensifying knowledge-base and constructing related information on 'ecosystem change from climate change (productivity, community structure, food chain, phenology, range distribution, and number of individuals) with the overall improvement of information contents and its quality. The respondents emphasized with the necessity of conducting field surveys of local ecosystem and constructing ecosystem inventories, advancing monitoring designs for climate change in ecosystem, and case studies for regional ecosystem changes with the guidance or guidelines for monitoring ecosystem change to enhance the quality of adaptation research and produce related information. In terms of activation for ecological information usage, national and local adaptation network should be working based on the integrated ecological platform necessary to support exchanges of knowledge and information and to expand ecosystem types in time and spatial dimension.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.25-33
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• 2021

Purpose : The purpose of this study is to evaluate the accuracy and usefulness of the Trigger mode for the Respiratory Gated Radiation Therapy (RGRT) Materials and methods : A QUASAR respiratory phantom that inserted a 3 mm fiducial marker (a gold marker) was used to estimate the accuracy of the Trigger mode. And the 20 bpm was used as reference respiration rate in this study. The marker that placed at the center of the phantom was contoured, and the lower threshold of a gating window was fixed at 2.0 mm using an OBI with Truebeam STx^TM. The upper threshold was measured every 0.5 mm from 1.0 mm to 3.0 mm. The respiration rates were changed every 10 bpm from 10 bpm to 60 bpm. We repeatedly measured five times to check the error rate of the trigger mode in the same condition. Result : The differences of a distance from a peak phase to upper threshold, 1.0 to 3.0 mm at a 20 bpm as a reference for 3 days in a row were 0.68±0.05 mm, 0.91±0.03 mm, 1.23±0.03 mm, 1.42±0.04 mm, and 1.66±0.06 mm, respectively. Measurement result of changes in respiratory rate compared to baseline respiratory rate in maximum absolute difference. The coefficient of determination (R2) to estimate the correlation between the respiration velocity and variation of absolute difference was on average 0.838, 0.887, 0.770, 0.850, and 0.906. The p-values of all the variables were below 0.05. Conclusion : Using Trigger mode during respiratory gated radiation therapy (RGRT), accuracy and usefulness of trigger mode at reference breathing rate were confirmed. However, inaccuracies depending on the rate of breathing it could be uncertain in case of respiration rate is faster than 20 bpm as a standard respiration rate compared to slower than 20 bpm. Consequently, when conducting a RGRT using the trigger mode, real time monitoring is required with well educated respiration.

• Research in Plant Disease
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• v.28 no.4
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• pp.221-230
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• 2022

The fire blight caused by Erwinia amylovora (Ea) was first reported in 2015 in Korea, and the disease has rapidly spread to 22 regions until 2021. In Korea, all host plants in the apple and pear orchards where fire blight occurred should be eliminated and buried by the Plant Protection Act. To prevent the spread of the disease, all burial sites were prohibited from planting the new host plants for the next three years. To confirm the eradication efficiency of Ea and the reoccurrence of fire blight, the surveillance facilities were established on three burial sites from 2019 to 2020 in Anseong-si, Gyeonggi-do, and Chungju-si, Chungcheongbuk-do. As host plants, five apple trees of fire blight-susceptible cultivar 'Fuji', were planted in each facility. All facilities were enclosed with fences and nets and equipped with two CCTVs, motion sensors, and several other sensors for recording weather conditions to monitor the environment of the sentinel plants in real-time. The sentinel plants were checked for the reoccurrence of fire blight routinely. Suspicious plant parts were collected and analyzed for Ea detection by loop-mediated isothermal amplification polymerase chain reaction and conventional polymerase chain reaction. Until November 2022, Ea has not been detected in all sentinel plants. These results might support that the burial control of infected plants in soil works efficiently to remove Ea and support the possibility to shorten the prohibition period of host plant establishment in the burial sites.

• Journal of Space Technology and Applications
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• v.4 no.3
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• pp.210-219
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• 2024

This study investigates various ionospheric and thermospheric disturbances around the Korean Peninsula during the G5 geomagnetic storm occurred on May 10, 2024. This level of storm was the first of its magnitude in 21 years, resulting in auroras visible even in South Korea and severe space weather worldwide. The Korea Astronomy and Space Science Institute has been providing ionospheric information over Korea through total electron content (TEC) measurements from the Global Navigation Satellite System (GNSS) and monitoring the impact of ionospheric disturbances on GNSS signals by operating five GNSS scintillation stations in Korea and other countries. During this storm period, large amplitudes of TEC variations were observed over South Korea, along with anomalous TEC enhancements accompanied by strong scintillations at night and persistent TEC depletion on the dayside during the storm's recovery phase. Such daytime TEC depletion disturbances are quite rare, typically occurring only a few times throughout the 11-year solar cycle. While the association of persistent TEC depletion during the daytime with neutral composition disturbances was identified through observations, the causes of TEC enhancement and strong scintillation at night remain unclear. We speculate that the uplift of the ionosphere by storm-induced electric fields is responsible for the TEC enhancement and scintillation, but this hypothesis requires validation based on additional observational data.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1361-1371
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• 2021

Among smart city services, the crime and disaster prevention sector accounted for the highest 24% in 2018. The most important platform for providing real-time situation information is CCTV (Closed-Circuit Television). Therefore, it is essential to create the actual CCTV surveillance coverage to maximize the usability of CCTV. However, the amount of CCTV installed in Korea exceeds one million units, including those operated by the local government, and manual identification of CCTV coverage is a time-consuming and inefficient process. This study proposed a method to efficiently construct CCTV's actual surveillance coverage and reduce the time required for the decision-maker to manage the situation. For this purpose, first, the exterior orientation parameters and focal lengths of the pre-installed CCTV cameras, which are difficult to access, were calculated using the point cloud data of the MMS (Mobile Mapping System), and the FOV (Field of View) was calculated accordingly. Second, using the FOV result calculated in the first step, CCTV's actual surveillance coverage area was constructed with 1 m, 2 m, 3 m, 5 m, and 10 m grid interval considering the occluded regions caused by the buildings. As a result of applying our approach to 5 CCTV images located in Uljin-gun, Gyeongsnagbuk-do the average re-projection error was about 9.31 pixels. The coordinate difference between calculated CCTV and location obtained from MMS was about 1.688 m on average. When the grid length was 3 m, the surveillance coverage calculated through our research matched the actual surveillance obtained from visual inspection with a minimum of 70.21% to a maximum of 93.82%.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.560-564
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• 2007

Korea Basic Science Institute(KBSI) has three general electron microscopes including High Voltage Electron Microscope(HVEM) which is the only one in Korea. Observed images through an electron microscope are what they are tilted by each step and saved, offering the more better circumstances for observers, a reconstruction to 3D could be a essential process. In this process, a warping method decreases distortions maximumly of avoided parts of a camera's focus. All these image treatment processes and 3D reconstruction processes are based on an accompaniment of a highly efficient computer, a number of Grid Node Personal computers share this process in a short time and dispose of it. Grid Node Personal computers' purpose is to make an owner can share different each other and various computing resources efficiently and also Grid Node Personal computers is applying to solve problems like a role scheduling needed for a constructing system, a resource management, a security, a capacity measurement, a condition monitoring and so on. Grid Node Personal computers accomplish roles of a highly efficient computer that general individuals felt hard to use, moreover, a image treatment using the warping method becomes a foundation for reconstructing to more closer shape with an real object of observation. Construction of the electron microscope volume 랜더링 system based on Grid Node Personal computer through the warping process can offer more convenient and speedy experiment circumstances to observers, and makes them meet with experiment outcome that is similar to real shapes and is easy to understand.