• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.433-439
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• 2020

This study, which was designed to improve and increase the utilization of female elk, examined the possibility of collecting their embryos during the non-reproductive period using ultrasound-guided Ovum Pick-Up (OPU) technology. Once follicles in the ovaries of an elk were observed, the embryos were retrieved through the absorption of the follicles using an OPU ultrasound probe. Fifty-seven embryos were retrieved from 85 follicles, giving a retrieval rate of 67.1%. Morphological evaluation of the recovered embryos revealed 14.0% embryos to be in grade A, 19.2% in grade B, 15.7% in grade C, and 50.8% in grade D. The developmental efficiency of the retrieved embryos was also investigated using in vitro maturation, in vitro fertilization, and in vitro culture. After cultivating 28 embryos through in vitro fertilization, 19 embryos were found to be fertilized; the fertilization rate was 67.9%. Four embryos developed to the blastocyst stage, indicating a 14.3% development rate. This study confirmed that the production of fertilized embryos from a seasonal breeder, such as elk, is possible via the ultrasound-guided OPU method. If the efficiency of in vitro fertilization and in vitro culture can be improved through further research, it will help improve the efficiency of elk embryo production through the transplantation of their fertilized embryos.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.217-221
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• 2015

When reactor coolant leaks occur due to cracks of a steam generator's tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000~7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In supercritical carbon dioxide method, we found that it also had a high decontamination efficiency. According to the results of these experiments, almost all decontamination method had a high efficiency, but considering the amounts of the secondary waste productions and work environment of the nuclear power plant, we judged the ultrasound and supercritical carbon dioxide method are suitable for application to the plant and we established the plant applicable decontamination process system on the basis of these two methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.56-64
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• 2021

Leakage due to deterioration and damage is one of the major causes of volume change by freezing and thawing, and it leads micro-cracking and surface scaling in concrete structures. The deterioration of damaged concrete accelerates with the chloride attack. Thus, in the detailed guidelines for facility performance evaluation (2020), the quality of cover concrete and the freeze-thaw (FT) repetition cycle were newly suggested for concrete durability assessment. The quality of cover concrete should be evaluated by the rebound hammer test and the FT repetition cycle should be also considered in the deterioration environmental assessment. This study suggested the application of fast dynamic based nonlinear ultrasound method to monitor initial micro-scale damage under freezing and thawing environment. Concrete specimens were fabricated with different water-cement ratios (40%, 60%) and air contents (1.5% and 3.0%). The compressive strength, rebound number, relative dynamic modulus, and nonlinear ultrasound were measured with different FT cycles. The scanning electron microscopy was also performed to investigate the micro-scale FT damage. As a result, both the rebound number and the relative dynamic modulus had difficulty to detect early damage but the proposed method showed a potential to detect initial micro-scale damage and predict the FT resistance performance of concrete.

• Journal of Powder Materials
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• v.8 no.3
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• pp.207-209
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• 2001

Nano particles have recently been a major research interest, motivated by their unusual physical and chemical properties. Such particles can be synthesized using physical and chemical methods. The physical methods need expensive installation like vacuum induction furnace, whereas in chemical methods the process in generally very simple and low cost. In this study, simple and new fabrication process by using ultrasound was investigated to prepare the nano-sized metal particles on various powders at room temperature.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2003.05a
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• pp.369-388
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• 2003

This research has been focused upon and analyzing Medison, once a leading New Technology-Based Firm (NTBF) in Korea with exceptionally advanced technology in 3D ultrasound diagnostic imaging devices (UDIDs) (armored with 23 subsidiaries at its peak expansion), from the perspective if Dynamic Firm Capability(DFC). The underlying hypothesis is that the various problems from its pointless pursuit of the business styles or precedents of the existing large firms might be traced to its specific characteristics as an NTBF, which should have more preferably been based upon the distinctive competences such as differentiated technologies, institutional linkages, organizational routines, and complementary assets, etc. In conclusion, for the NTBFs with different DFC domains from those of the large firms, the optimal external linkages and comprehensive integration efforts (Process) under their specific organizational characteristics and constraints (Path) are highly recommended for the continuous accumulation of their core capabilities based upon the technological assets (Position).

• Journal of Korea Technology Innovation Society
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• v.6 no.2
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• pp.228-252
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• 2003

This research has been focused upon and analyzing Medison, once a leading New Technology-Based Finn (N1BF) in Korea with exceptionally advanced technology in 3D ultrasound diagnostic imaging devices (UDIDs) (armored with 23 subsidiaries at its peak expansion), from the perspective of Dynamic Finn Capability(DFC). The underlying hypothesis is that the various problems from its pointless pursuit of the business styles or precedents of the existing large firms might be traced to its specific characteristics as an NTBF, which should have more preferably been based upon the distinctive competences such as differentiated technologies, institutional linkages, organizational routines, and complementary assets, etc. In conclusion, for the NTBFs with different DFC domains from those of the large firms, the optimal external linkages and comprehensive integration efforts (Process) under their specific organizational characteristics and constraints (path) are highly recommended for the continuous accumulation of their core capabilities based upon the technological assets (Position).

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.315-319
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• 2021

Recent impact of 4th industrial revolution is increasing usage of IoT technology along with smartphones and tablet PC. However blue light emitted from electronic devices such as smartphones and tablet PC causes detrimental change to human bodies. As the controversy over the harmfulness of blue light became known through the media and various communities, related markets were formed, and various blocking films, software, and vision protection monitors were released. In this paper focuses on utilizing IoT technology to protect human organizations from blue light. It presents anti-blue light system which prevents excessive exposure to blue light through Arduino module such as ultrasound, piezo buzzer and blue light measurement module.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.145-153
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• 2015

Thyroid nodules are an endocrine disease often found in clinical practice, and patients with thyroid nodules found by chance have rapidly increased alongside development of thyroid ultrasound techniques for health examination purposes. This study analyzes the subjects' general characteristics, thyroid ultrasounds, and fine needle aspiration cytology in order to find out the relationship between male and female thyroid nodules and thyroid cancer frequency. An ultrasound examination of the thyroid was performed for 32,973 individuals who visited the K Hospital of Health Examination. Subjects have no history of thyroid disease and are 20 years old or over. Data of general characteristics, diabetes) was collected by a written survey completed by the subject, and the ultrasound of the thyroid(thyroid nodules existence, size, number) and FNAC was used to find out the malignancy rate. Frequency of patients with thyroid nodule was 4,611(26.1%) in men and 5,341(34.9%) in women between 32,973 individuals. Women's prevalence rate is significantly higher than men, and the prevalence rate significantly increased with age in men and women(p < 0.05). The prevalence of multiple nodules was significantly higher in women(43.5%) than in men(35.6%), and significantly increased with age in men and women(p < 0.05). The fine needle aspiration cytology was performed in 692(men 342, women 350) subjects who showed signs of malignancy through ultrasound. Prevalence of malignancy of the nodules was higher in men(33.3%) than in women(29.4%) although it is not statistically significant. It is known that thyroid nodule prevalence in women is much higher than in men. But this study shows the men's prevalence rate was not too low compared with women, and the men showed a rather higher malignancy rate in nodules than women. It is considered that the role of thyroid ultrasound is both important in men and women.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1107-1113
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• 2018

Ultrasonography and photodynamic therapy have been proposed as useful tools as a treatment for inducing necrosis of cells using reactive oxygen species. Apoptosis is an internal mechanism necessary for cells regardless of damage. Ultrasound has the effect of inducing the apoptosis of these cells, and the frequency of 1 MHz is the most applicable area for medical use. The laser which is generally used in photodynamic therapy has a heat reaction and the treatment is limited. However, as a small light emitting diode is developed, it shows possibility to minimize the equipment and reduce heat reaction. On the other hand, there are relatively few researches on direct effects of light compared with studies using photosensitizers, and the area is also limited. Therefore, in this paper, we have developed a cancer cell proliferation control module using ultrasonic and light emitting diodes, which have relatively few side effects, and quantitatively analyze the effect of the module to propose an optimal suppression technique.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.374-379
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• 2019

This study developed predictive growth models of Salmonella enterica Serovar Typhimurium on lettuce washed with chlorine (100~300 ppm) and ultrasound (US, 37 kHz, 380 W) treatment and stored at different temperatures ($10{\sim}25^{\circ}C$) using a polynomial equation. The primary model of specific growth rate (SGR) and lag time (LT) showed a good fit ($R^2{\geq}0.92$) with a Gompertz equation. A secondary model was obtained using a quadratic polynomial equation. The appropriateness of the secondary SGR and LT model was verified by coefficient of determination ($R^2=0.98{\sim}0.99$ for internal validation, 0.97~0.98 for external validation), mean square error (MSE=-0.0071~0.0057 for internal validation, -0.0118~0.0176 for external validation), bias factor ($B_f=0.9918{\sim}1.0066$ for internal validation, 0.9865~1.0205 for external validation), and accuracy factor ($A_f=0.9935{\sim}1.0082$ for internal validation, 0.9799~1.0137 for external validation). The newly developed models for S. Typhimurium could be incorporated into a tertiary modeling program to predict the growth of S. Typhimurium as a function of combined chlorine and US during the storage. These new models may also be useful to predict potential S. Typhimurium growth on lettuce, which is important for food safety purposes during the overall supply chain of lettuce from farm to table. Finally, the models may offer reliable and useful information of growth kinetics for the quantification microbial risk assessment of S. Typhimurium on washed lettuce.