• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.15-21
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• 2008

It was previously pointed out that mutation is the ultimate source of variation. Adequate variation is needed for plant breeding if there is a limitation in natural genetic resources. When the ionizing radiation has been known to cause chromosomal and genomic alternations, it is widely used for inducing mutagenesis. The electron beam as an ionizing radiation is the principal physical mutagens that induces mutation and effectively used in plant breeding. Since dose-response relationships of electron beam in plant species are rarely known, we investigated the seed germination rate and early seedling growth of irradiated seeds of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1) with various electron beam irradiating conditions (1, 1.3, 2 MeV at both 0.03 mA and 0.06 mA with dose of 100 Gy (Gray) and 0.03, 1, 1.3, 2 MeV at 0.03 mA with dose of 200 Gy, respectively) using electron accelerator at Korea Atomic Energy Research Institute. The growth parameters in terms of shoot length, primary root length, and secondary root length showed similar response between 0.06 / 1 (mA / MeV) at 100 Gy and 0.03 / 0.3 (mA / MeV) at 200 Gy. Bentgrass seed germination was mainly affected by the intensity of irradiated dose (Gray). Germination rate was lowered as the irradiated dose increased. On the other hand, early seedling growth was mainly governed not by the dose of radiation but by voltage.

• Journal of Korean Dental Science
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• v.11 no.2
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• pp.62-70
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• 2018

Purpose: Bone marrow has long been a source of primary cells. This study was performed to evaluate the effects of age and sex on the cellular viability and expression of stem cell markers of mRNA and on the protein expression of bone marrow stem cells (BMSCs) derived from healthy donors. Materials and Methods: Stem cells were isolated from human bone marrow and plated in culture plates. The shape of the BMSCs was observed under inverted microscope. Quantitative cellular viability was evaluated using a Cell-Counting Kit-8 assay. The expression of stem cell surface markers was tested and a series of quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot was performed to evaluate the expression in each group. Result: The shapes of the cells at 20s, 30s, and 50s were similar to each other. No significant changes in cellular viability were noted among different age groups or sex groups. The BMSCs expressed CD44, CD73, and CD90 surface markers but did not express CD14 and CD34. There were no noticeable differences in CD surface markers among the different age groups. The expressions of CD surface markers were similar between men and women. No significant differences in the secretion of vascular endothelial growth factors (VEGFs) were noted at Day 3 between different age groups. qRT-PCR regarding the expression showed differences between the age groups. However, Western blot analysis showed a decrease in expression but did not reach statistical significance (P>0.05). Conclusion: This study clearly showed no significant differences in shape, cell viability, expression of stem cell surface markers, or secretion of human VEGF among different age groups. However, western blot analysis showed a tendency of age-related decrease which did not reach statistical significance. Collectively, autologous or allogeneic BMSCs should be meticulously applied to obtain optimal results regarding age and sex.

• The Korean Journal of Archival Studies
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• no.11
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• pp.123-143
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• 2005

1. Introduction : From the Memorial to the Records, From the Records to the Archives 2. Archivists and Historians : the Records Keeping, Appraisal and Selection 3. Records and Historical Materials in the Historical Narrative 4. the Relation of the Facts and Theory in the History 5. Conclusion In this essay I considered the relations of records and history, namely the process on the selection and choice from the records to the archives and the historical materials and in the process the role on the archivists and historians and difference and the relation of the facts and theory in the history. Archival science posits that an archives is the whole of the documents made or received in the course of purposeful activity, and of the relationships among those documents. Archival theory posits that it is the primary function of the archivists to maintain unbroken, continuing custody of societal archives, and to protect their integrity by keeping them physically and intellectually uncorrupted. The ultimate purpose of archival endeavors is to hand down to the next generations a reliable, trustworthy, and complete testimony of societal actions so that they can constitute sources of, and foundations for, future decision making. However, historical science searches for the truth in the historical facts, explains the cause and origin of the matters and reflects on th knowledge about the why and how the events happened. And history is firmly rooted on the philosophy. The goal of historian is analysing the nature of meaning of past in the society and tracing up the change and process of the transition. Archival science means historical source studies and other related disciplines. On the other hand archival management is the principle of respect for original order and the importance of original forms and conditions. Thus the relations between archival science and archives management are not one-sided but mutual. Archival science and historical studies, archivists and historians need to link more closely in order to hand down the contemporary memorial, the common memorial of mankind to the future.

• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.79-88
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• 2019

Background: The main goal of experiments is to compare various operational and technical characteristics of D-Shuttle semiconductor personal dosimeters of the Japanese company "Chiyoda Technol Corporation" and Harshaw thermoluminescent dosimeters (TLD) manufactured by "Thermo Fisher Scientific" and DTL-02 of the Russian Research and Production Enterprise (RPE) "Doza" by their occupational and calibration exposure at various dose equivalents from 0.5 to 20 mSv of gamma-radiation. Materials and Methods: Besides dosimeters DTL-02, D-Shuttle and Harshaw TLD, there were also used: (1) the primary reference radionuclide source Hopewell Designs IAEA: G10-1-12 with $^{137}Cs$ isotope (an error is not more than 6% and activity is 20 Ci), and (2) the verification device UPGD-2M of RPE "Doza" and installed in the National Center for Expertise and Certification of the Republic of Kazakhstan (Kapchagai, the National Center for Expertise and Certification). Results and Discussion: The main results of researches are the following: (1) TLDs for Harshaw 6600 and DVG-02TM have an approximately equal measurement accuracy of the individual dose equivalents in the range from 0.5 to 20 mSv of gamma-radiation. (2) Advantages of dosimeters for Harshaw 6600 are due to the high measurement productivity and opportunity to indicate the dose on the skin $H_p$(0.07). Advantages of DVG-02TM consist of operation simplicity and lower cost than of Harshaw 6600. (3) D-Shuttles are convenient for use in the current and the operational monitoring of ionizing radiation. Measurement accuracy and 10% linearity of measurements are ensured when D-Shuttle is irradiated with dose equivalents below 1 mSv at the equivalent dose rate not higher than $3mSv{\cdot}hr^{-1}$. This allows using D-Shuttle at a routine technological activity. Conclusion: The obtained results of experiments demonstrate advantages and disadvantages of D-Shuttle semiconductor dosimeters in comparison with two TLD systems of DVG-02TM and Harshaw 6600.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1514-1524
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• 2019

Hydrogen-steam gas mixture may be injected into containment with flow regime varying both spatially and transiently due to wall effect and pressure difference between primary loop and containment in severe accidents induced by loss of coolant accident. Preliminary CFD analysis is conducted to gain information about the helium flow regime transition process from jet to buoyancy plume for forthcoming experimental study. Physical models of impinging jet and wall condensation are validated using separated effect experimental data, firstly. Then helium transportation is analyzed with the effect of jet momentum, buoyancy and wall cooling discussed. Result shows that helium distribution is totally dominated by impinging jet in the beginning, high concentration appears near gas source and wall where jet momentum is strong. With the jet weakening, stable light gas layer without recirculating eddy is established by buoyancy. Transient reversed helium distribution appears due to natural convection resulted from wall cooling, which delays the stratification. It is necessary to concern about hydrogen accumulation in lower space under the containment external cooling strategy. From the perspective of experiment design, measurement point should be set at the height of connecting pipe and near the wall for stratification stability criterion and impinging jet modelling validation.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.279-285
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• 2019

Objective: This study evaluated the efficiency of anchorage provided by temporary anchorage devices (TADs) in maxillary bicuspid extraction cases during retraction of the anterior teeth using a fixed appliance. Methods: Patients aged 12 to 50 years with malocclusion for which bilateral first or second maxillary bicuspid extractions were indicated were included in the study and randomly allocated to the TAD or control groups. Retraction of the anterior teeth was achieved using skeletal anchorage in the TAD group and conventional dental anchorage in the control group. A computed tomography (CT) scan was performed after alignment of teeth, and a second CT scan was performed at the end of extraction space closure in both groups. A three-dimensional superimposition was performed to visualize and quantify the maxillary first molar movement during the retraction phase, which was the primary outcome, and the stability of TAD movement, which served as the secondary outcome. Results: Thirty-four patients (17 in each group) underwent the final analysis. The two groups showed a significant difference in the movement of the first maxillary molars, with less significant anchorage loss in the TAD group than that in the control group. In addition, TAD movement showed only a slight mesial movement on the labial side. On the palatal side, the mesial TAD movement was greater. Conclusions: In comparison with conventional dental anchorage, TADs can be considered an efficient source of anchorage during retraction of maxillary anterior teeth. TADs remain stable when correctly placed in the bone during the anterior tooth retraction phase.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.1
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• pp.65-74
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• 2021

Purpose: The coronavirus disease 2019 (COVID-19) pandemic has influenced the lives of people worldwide. Little is known about the effects of the COVID-19 pandemic on the behavior and fears of pediatric patients with inflammatory bowel disease (IBD) and their families. We conducted a survey to determine the COVID-19 exposure, related perceptions, and information sources; medication compliance; and patients' and parents' behaviors, fears, and physician contact. Methods: An anonymous cross-sectional survey of pediatric patients with IBD and their parents at one pediatric gastroenterology unit of a university medical center was performed. Results: A total of 46 pediatric patients with IBD and 44 parents completed the survey. Parents of pediatric patients with IBD had high fear of their children becoming infected with severe acute respiratory syndrome coronavirus 2. They perceived schools as the most hazardous environment, whereas the children did not. Half the pediatric patients with IBD feared infection. Patients and parents felt sufficiently informed about COVID-19. The primary source of guidance for pediatric patients was their parents (43%), followed by television and social media, whereas the parents mainly consulted internet news websites (52.2%), television, and public health institutes. Pediatric patients with IBD adhered to their prescribed medication. They also showed cautious behavior by enhancing hand hygiene (84%) and leaving the house less frequently than before. However, in-person medical visits remained favored over video consultations. Conclusion: Although parents expressed overprotective concerns, both parents and pediatric patients with IBD are coping well with the COVID-19 pandemic. IBD-relevant information should be actively conveyed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.768-777
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• 2020

In this paper, we describe recent research results on AODV routing protocol, which is widely deployed at mobile ad hoc networks, and AODV related routing protocols with multi-path routing schemes. We suggest the critical problems which minimum hop routing schemes have, such as AODV routing protocol, and then, propose a new C-AODV routing protocol with two routing metrics: the primary metric is the hop count, the secondary metric is the sum of link delay times. We implemented C-AODV protocol by modifying AODV at the NS-3, and thus, elaborate on how we change the original AODV source code of NS-3 in order to implement the C-AODV scheme. We show numerical comparison of C-AODV scheme with the original AODV scheme and then, discuss how much the C-AODV enhances routing performance over AODV protocol. In conclusion, we present future research items.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.4
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• pp.553-559
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• 2020

Seaweed(Laver), Korea's largest export product, is currently focused on mass production due to the market situation in Korea. This naturally led to a decrease in the quality of seaweed. Therefore, in this paper, the present method was produced and tested by changing the way of adjusting the ratio of seaweed mixing, which was dependent on the user's sense and experience in the production of seaweed. In addition, I developed an embedded measurement system that can determine the concentration of a mixture of gold in real time based on primary image information obtained through an IR LED lamp that generates a light source and a photo sensor that detects concentration. By collecting and storing precise data in real time, it is easier to cope with the previous year's data in a work environment that is repeated every winter.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.58-63
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• 2021

This research aims to reconsider the necessity of an alternative way(s) for contemporary actor training and acting in discussing and articulating Diderot and Suzuki's concepts and approaches for acting/training. First of all, the physical body, assumed and conceptualized by Diderot is beyond our control by means of a type of radical body/mind dualism, and is based on the concept that body and mind are separate. In contrast, Suzuki's notion of acting/training is raised by his concern about the role of an actor's body in the constitution of an actor's bodily experience against the imitation of the West-oriented theatre/acting/training. The descriptions of the two theatre artists' notion of acting/training gives us insight into the place and role of contemporary theatre as a practical root to encounter and communicate between a doer and a spectator where an actor's body must appropriately be attuned and cultivated towards the cultivation of bodily attributes which are foundation but usually neglected by actors/directors/practitioners particularly in Korea. Especially, misunderstanding of a specific training sources/approaches, namely 'scientific system' and the 'method' have taken us away from the potential possibilities of the lived oneness. Here, the 'possibility' refers to the primary bodily functions within a specific context or being in the here and now rather than attempting to copying, imitating and/or adapting a specific cultural source(s)/approaches/techniques as we have faced with through the previous century. We reconsider and argue that a potential way to correspond the nature of theatre/acting/training is that how to meet the demand of contemporary spectators which in turn intensifies an actor's stability, sustainability and hopefully professional identity in this contemporary era.