• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.441-444
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• 2016

Peace on the Korean Peninsula is threatened by physical aggressions and cyber terrors such as nuclear tests, missile launchings, senior government officials' smart phone hackings and DDos attacks to banking systems. Cyber attacks such as vulnerability for the hackings, malware distributions are generally defended by passive defense through the detecting signs of first invasion and attack, data analysis, adding library and updating vaccine programs. In this paper the concept of security program based on Google TensorFlow machine learning ability to perform adding libraries and solving security vulnerabilities by itself is researched and proposed.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.2
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• pp.151-156
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• 2022

Liposomes are bilayered particles that are surrounded by an aqueous solvent with amphiphilic substances such as phospholipids. Liposomes have the potential to overcome the limitations of physiochemical properties of existing drugs, and are therefore widely used in research for the treatment of many diseases, especially cancer. Currently, there are many liposome manufacturing methods that use various lipids and amphiphiles. Among them, the thin film-hydration method is a traditional and very simple method to prepare liposomes by hydrating a dry lipid film in an aqueous solvent, which has been widely used in the laboratory until recently. Recently, approaches to new nuclear imaging agents and radiotherapy by loading radioactive isotopes inside liposomes have been actively studied. In this review, we would like to discuss considerations for preparing liposomes using the thin film-hydration method.

• Journal of Radiation Protection and Research
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• v.46 no.2
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• pp.80-82
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• 2021

Dr. Haruyuki Ogino, a member of the Japan Health Physics Society (JHPS), was awarded the 2021 Bo Lindell Medal by the International Commission on Radiological Protection (ICRP). To commemorate this, the "Joint JHPS-KARP-ARPS program for young radiation protection (RP) scientists to discuss the future of RP" was organized via a web meeting system. First, Dr. Ogino gave a lecture, and then young researchers selected from each academic society made presentations on the future of RP. After the presentations by the three researchers, a free talk was held-young researcher groups of each country being active is a great opportunity to collaborate and exchange information. It was emphasized that the low awareness of knowledge related to radiation has been common to all of the participating countries. Thus, it is necessary to utilize communication via web technology, as done for this program, effectively. One of the biggest advantages for Asia and Oceania is that we do not have a significant time difference. The round-table discussion was concluded by expressing the hope of active exchange and development of young researchers in the future.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.234-240
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• 2007

Purpose: In this study we propose a block-iterative method for reconstructing Compton scattered data. This study shows that the well-known expectation maximization (EM) approach along with its accelerated version based on the ordered subsets principle can be applied to the problem of image reconstruction for Compton camera. This study also compares several methods of constructing subsets for optimal performance of our algorithms. Materials and Methods: Three reconstruction algorithms were implemented; simple backprojection (SBP), EM, and ordered subset EM (OSEM). For OSEM, the projection data were grouped into subsets in a predefined order. Three different schemes for choosing nonoverlapping subsets were considered; scatter angle-based subsets, detector position-based subsets, and both scatter angle- and detector position-based subsets. EM and OSEM with 16 subsets were performed with 64 and 4 iterations, respectively. The performance of each algorithm was evaluated in terms of computation time and normalized mean-squared error. Results: Both EM and OSEM clearly outperformed SBP in all aspects of accuracy. The OSEM with 16 subsets and 4 iterations, which is equivalent to the standard EM with 64 iterations, was approximately 14 times faster in computation time than the standard EM. In OSEM, all of the three schemes for choosing subsets yielded similar results in computation time as well as normalized mean-squared error. Conclusion: Our results show that the OSEM algorithm, which have proven useful in emission tomography, can also be applied to the problem of image reconstruction for Compton camera. With properly chosen subset construction methods and moderate numbers of subsets, our OSEM algorithm significantly improves the computational efficiency while keeping the original quality of the standard EM reconstruction. The OSEM algorithm with scatter angle- and detector position-based subsets is most available.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.6
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• pp.333-343
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• 2018

In this paper, we study the existing results of the structure-soil-structure interaction (SSSI) effect on seismic responses of structures and summarize important parameters. The parameters considered in this study are a combination of buildings in the power block of a nuclear power plant, the characteristics of earthquake ground motions and its direction, and the characteristics embedded under the ground. Based on these parameters, the seismic analysis model of the structures in the power block of the nuclear power plant is developed and the structure-soil-structure interaction analyses are performed to analyze the influence of the parameters on the seismic response. For all analyses, the soil-structure interaction (SSI) analysis program CNU-KIESSI, which was developed to enable large-sized seismic analysis, is used. In addition, the SSI analyses is performed on individual structures and the results are compared with the SSSI analysis results. Finally, the influence of the parameters on the seismic response of the structure due to the SSSI effect is reviewed through comparison of the analysis results.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.91-99
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• 2017

Domestically developed concrete storage casks include an internal canister to maintain the confinement integrity of radio-active materials. In this study, we analyzed the depth of flaws caused by loads that propagate canister weld cracks under normal, off-normal and accident conditions, and evaluated the maximum allowable weld flaw depth needed to secure the structural integrity of the canister weld and to reduce the welding time of the internal canister lid of the concrete storage cask. Structural analyses for normal, off-normal and accident conditions were performed using the general-purpose finite element analysis program ABAQUS; the allowable flaw depth was assessed according to ASME B&PV Code Section XI. Evaluation results revealed an allowable canister weld flaw depth of 18.75 mm for the concrete storage cask, which satisfies the critical flaw depth recommended in NUREG-1536.

• Corrosion Science and Technology
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• v.14 no.1
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• pp.12-18
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• 2015

Since the operation period of nuclear power plants has increased, the degradation of buried pipes gradually increases and recently it seems to be one of the emerging issues. Maintenance on buried pipes needs high quality of management system because outer surface of buried pipe contacts the various soils but inner surface reacts with various electrolytes of fluid. In the USA, USNRC and EPRI have tried to manage the degradation of buried pipes. However, there is little knowledge about the inspection procedure, test and manage program in the domestic nuclear power plants. This paper focuses on the development and build-up of real-time monitoring and control system of buried pipes. Pipes to be tested are tape-coated carbon steel pipe for primary component cooling water system, asphalt-coated cast iron pipe for fire protection system, and pre-stressed concrete cylinder pipe for sea water cooling system. A control system for cathodic protection was installed on each test pipe which has been monitored and controlled. For the calculation of protection range and optimization, computer simulation was performed using COMSOL Multiphysics (Altsoft co.).

• Development and Reproduction
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• v.19 no.2
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• pp.79-84
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• 2015

The Korean native pig (KNP) have been considered as animal models for animal biotechnology research because of their relatively small body size and their presumably highly inbred status due to the closed breeding program. However, little is reported about the use of KNP for animal biotechnology researches. This study was performed to establish the somatic cell nuclear transfer (SCNT) protocol for the production of swine leukocyte antigens (SLA) homotype-defined SCNT KNP. The ear fibroblast cells originated from KNP were cultured and used as donor cell. After thawing, the donor cells were cultured for 1 hour with 15 ${\mu}M$ roscovitine prior to the nuclear transfer. The numbers of reconstructed and parthenogenetic embryos transferred were $98{\pm}35.2$ and $145{\pm}11.2$, respectively. The pregnancy and delivery rate were 3/5 (60%) and 2/5 (40%). One healthy SLA homotype-defined SCNT KNP was successfully generated. The recipient-based individual cloning efficiency ranged from 0.65 to 1.08%. Taken together, it can be postulated that the methodological establishment of the production of SLA homotype-defined cloned KNP can be applied to the generation of transgenic cloned KNP as model animals for human disease and xenotransplantation researches.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.63-69
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• 2012

The second phase of the national program for fusion energy development in Korea starts from 2012 for design and construction of the fusion DEMO reactor. Radiological assessment for the fusion reactor is one of the key tasks to assure its licensability and the starting point of the assessment is determination of the source terms. As the first effort, the activities of the coolant due to activated corrosion product (ACP) were estimated. Data and experiences from fission reactors were used, in part, in the calculations of the ACP concentrations because of lack of operating experience for fusion reactors. The MCNPX code was used to determine neutron spectra and intensities at the coolant locations and the FISPACT code was used to estimate the ACP activities in the coolant of the fusion DEMO reactor. The calculated specific activities of the most nuclides in the fusion DEMO reactor coolant were 2-15 times lower than those in the PWR coolant, but the specific activities of $^{57}Co$ and $^{57}Ni$ were expected to be much higher than in the PWR coolant. The preliminary results of this study can be used to figure out the approximate radiological conditions and to establish a tentative set of radiological design criteria for the systems carrying coolant in the design phase of the fusion DEMO reactor.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.26-33
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• 2010

A computed Radiography (CR) system by use of reusable Image Plate (IP) offers a convenient and reliable way to replace a conventional film-screen system for NDT (non-destructive testing) field. The quality of a radiography to detect a defect of welded objects depends on the procedure embracing several factors such as measurement conditions, image plate type/class, radiation energy, radiation type, and source to image plate distance. Also, the ability of images to detect a flaw reduces with increasing object thickness. In the study, the properties of gamma ray source were summarized for NDT field and inspection images of CR image system manufactured by FUJI were acquired using $^{75}Se$ and $^{192}Ir$ with welded objects. We analyzed the gray scale of hole defect image by using XCAP image processing program and calculated the image contrast and SNR in definition. Also the sesitivities of image quality indicator(IQI) were calculated for hot and cooling tube image of $^{75}Se$ and $^{192}Ir$.