• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.141-147
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• 2019

Recently, the biggest issue in the electricity industry is the increase in renewable energy, and various technologies are being developed to ensure the capacity of the power system. In addition, super-grids linking power systems are being pushed to utilize eco-friendly energy between countries and regions worldwide. The HVDC transmission technology is required to link the power network between regions with different characteristics of the power system such as frequency and voltage. Until now, Korea has applied HVDC transmission technology that connects mainland and Jeju Island with submarine cables. But, the HVDC transmission technology is still developing for long-distance high-capacity power transmission from power parks on the east coast to load-tight areas near the metropolitan area. Considering the high population density and mountainous domestic environment, it is pushing for commercialization of the design technology of the ${\pm}500kV$ Double Bipole with metallic return wire transmission line to transmit large-scale power of 8 GW using minimal right of ways. In this paper, the insulation characteristics were studied for the design of double-bipole transmission tower with metallic return wire, which is the first time in the world. And the air insulation characteristics resistant to the various overvoltage phenomena occurring on transmission lines were verified through a full-scale impulse voltage test.

• Korean Journal of Construction Engineering and Management
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• v.22 no.5
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• pp.86-98
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• 2021

In this study, we developed a simulation model for supply chain management of Precast Concrete (PC) based construction. To this end, information on the Factory Production/Site Construction system was collected through literature review and field research, and based on this information, a simulation model was defined by describing the supply chain, entities, resources, and processes. Next, using the Arena simulation software, a simulation model for the PC supply chain was developed by setting model frameworks, data modules, flowchart modules, and animation modules. Finally, verification and validation were performed using five review methodologies such as model check, animation check, extreme value test, average value test, and actual case test to the developed model. As a result, it was found that the model adequately represented the flows and characteristics of the PC supply chain without any logical errors and provided accurate performance evaluation values for the target supply chains. It is expected that the proposed simulation model will faithfully play a role as a performance evaluation platform in the future for developing management techniques in order to optimally operate the PC supply chain.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1261-1272
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• 2018

It is important to measure the Arctic surface air temperature because it plays a key-role in the exchange of energy between the ocean, sea ice, and the atmosphere. Although in-situ observations provide accurate measurements of air temperature, they are spatially limited to show the distribution of Arctic surface air temperature. In this study, we proposed machine learning-based models to estimate the Arctic surface air temperature in summer based on buoy data and Advanced Microwave Scanning Radiometer 2 (AMSR2)satellite data. Two machine learning approaches-random forest (RF) and support vector machine (SVM)-were used to estimate the air temperature twice a day according to AMSR2 observation time. Both RF and SVM showed $R^2$ of 0.84-0.88 and RMSE of $1.31-1.53^{\circ}C$. The results were compared to the surface air temperature and spatial distribution of the ERA-Interim reanalysis data from the European Center for Medium-Range Weather Forecasts (ECMWF). They tended to underestimate the Barents Sea, the Kara Sea, and the Baffin Bay region where no IABP buoy observations exist. This study showed both possibility and limitations of the empirical estimation of Arctic surface temperature using AMSR2 data.

• Journal of Life Science
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• v.29 no.9
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• pp.1034-1046
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• 2019

The mitochondria is the major cellular organelle of energy metabolism for the supply of cellular energy; it also plays an important role in controlling calcium regulation, reactive oxygen species (ROS) production, and apoptosis. Mitochondrial dysfunction causes various diseases, such as neurodegenerative diseases, Lou Gehrig's disease, cardiovascular disease, mental disorders, diabetes, and cancer. Most of the diseases are age-related diseases. In this review, we focus on the roles of mitochondrial dysfunction in cancer. Mitochondrial dysfunction induces carcinogenesis and is found in many cancers. The factors that cause mitochondrial dysfunction differ depending on the types of carcinoma, and those factors could cause cancer malignancy, such as resistance to therapy and metastasis. Mitochondrial dysfunction is caused by a lack of mitochondria, an inability to provide key substances, or a dysfunction in the ATP synthesis machinery. The main factor associated with cancer malignancy is mtDNA depletion. Mitochondrial dysfunction would leads to malignancy through changes in molecular activity or expression, but it is not known in detail which changes lead to cancer malignancy. In order to explore the relationship between mitochondrial dysfunction and cancer malignancy in detail, mitochondria dysfunctional cell lines are constructed using chemical methods such as EtBr treatment or gene editing methods, including shRNA and CRISPR/Cas9. Those mitochondria dysfunctional cell lines are used in the study of various diseases caused by mitochondrial dysfunction, including cancer.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.1
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• pp.76-84
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• 2019

This study was conducted for the purpose of examining the Outstanding Universal Value, World Heritage Values, in Suzhou classical gardens and the operational method of the protection management of historic gardens, and the results of the study are as follows; The first, as a world heritage, Suzhou gardens proved OUV by showing the taste and lifestyle of the literati, the unique class of Chinese history, to the natural environment of the East Yangtze Delta region. In addition, it showed the exchange of international culture with unique Chinese garden techniques. Second, a authentic reconstruction of garden have original value because it exist records of the near past. The 20th-century archives described by the contemporary language and describing the heritage through images using such media as photography and drawing played a decisive role in restoring gardens. Third, the protection management of Suzhou gardens, which began in the 1950s, was carried out in detail, including the reconstruction of components such as buildings, the restoration of plant materials and horticulture technique, the creation of a list through the records of trees, the maintenance of props such as plaque, furniture, and the project to improve water quality and restore waterscape. The last, after the World Heritage inscribing, Garden's protection management was proceeded in two directions. One is that through the reorganization of the administrative management system and the enactment of laws related to Suzhou classical Gardens, the listing heritage is strictly protected and managed, and the other is that the historical gardens are used to establish urban masterplan and urban identity in Suzhou. The range of garden properties greatly expanded by distinguishing the principle of conservation from protection to rational use and the grade of protection, such as whole protection, maintenance protection and protection of historical sites.

• The Mathematical Education
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• v.61 no.3
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• pp.419-439
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• 2022

This study is based on Freudenthal's mathmatising process and the didactical phenomenology of linear function concept, I have described and examined the process in which students represent the constant rate of change into tables, graphs and equations and, in this way, how they construct mental objects and essence of the linear function concept. The students used the proportionality as composite units, when they represented the phenomenon with constant rate of change into tables. When representing in graphs, all but one student represented it into a line. There were differences among the students in the level they were using the given conditions, co-variation perspective, and corresponding rules when formulating equations. The students compared the relationship between two variables in a multiplicative way, and under the guidance of teachers they reached to the understanding that its relationship becomes a constant. Moreover, they could construct mental objects of a constant rate of change, understanding the situation where the relationship between time difference and distance difference becomes one value, namely speed. The students had difficulties in connecting the rate of change with the inclination of a line. The students constructed the essence (concept) of linear functions, after building and organizing the image that the rate of change is constant, the graph is linear, and the equation is formulated as y=ax+b (a: inclination, b: intercept).

• Journal of Science Education
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• v.47 no.1
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• pp.52-62
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• 2023

This study examines how prospective earth science teachers perceive the concept of "equilibrium" and "interaction between Earth's spheres" in understanding Earth's radiative equilibrium and tries to identify their misconceptions. For this purpose, a questionnaire was designed and put to them to look into their thought flow based on the items that appeared in the national level evaluation. As a result of analyzing their answers, even though all the prospective teachers correctly described the concept of radiative equilibrium, about 90% of them did not apply the concept of radiative equilibrium to the new environment of the Earth without atmosphere. They do not seem to be able to smoothly derive the concept of a new 'interaction' between the changed regions and a new 'equilibrium' that will be reached over a long period of time. In this respect, it is likely that the textbooks had some influence on the formation of their concepts. In particular, high school Earth Science textbooks describe the Earth's radiation equilibrium in a quantitative manner, focusing on the heat budget of the equilibrium state rather than the process of reaching radiation equilibrium. Such an approach of textbooks might be an obstacle to fostering students into creative convergence-type talents pursued in the 2015 revised curriculum. Meanwhile, in order to eliminate the misconceptions of students often found in the understanding of Earth's radiation equilibrium, this study suggests that the core concepts need to be dealt with more attention even in college courses for training prospective teachers.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.63-75
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• 2012

This paper gives some basic requirements and preferences of various geological environmental conditions for the final deep geological repository of spent nuclear fuel (SNF). This study also indicates how the requirements and preferences are to be considered prior to the selection of sites for a site investigation as well as the final disposal in Korea. The results of the study are based on the knowledge and experience from the IAEA and NEA/OECD as well as the advanced countries in SNF disposal project. This study discusses and suggests preliminary guideline of the disposal requirements including geological, mechanical, thermal, hydrogeological, chemical and transport properties of host rock with long term geological stabilities which influence the functions of a multi-barrier disposal system. To apply and determine whether requirements and preferences for a given parameter are satisfied at different stages during a site selection and suitability assessment of a final disposal site, the quantitative criteria in each area should be formulated with credibility through relevant research and development efforts for the deep geological environment during the site screening and selection processes as well as specific studies such as productions of safety cases and validation studies using a generic underground research laboratory (URL) in Korea.

• Journal of Hospice and Palliative Care
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• v.4 no.1
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• pp.47-56
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• 2001

Purpose : Surveying the effects on drop the anxiety of the hospice patients in spiritual nursing intervention with a quasi-experimental design using non-equivalent contrast group non-synchronized design to try in order to give the support which provide a holistic and individualizational nursing to comfort of hospice patients. Method : The results of survey were collected from 67 patients(67 subjects comprised 37 hospice patients of the experimental group and 30s of contrast) who were given hospice care from July to September of 2000 at the General Hospital in Cheon Ju city. The tool was used Spielberger's State Anxiety Scale, and the difference in the level of dropping anxiety among patient groups was analyzed with the mean, standard deviation, $x^2-test$. t-test and paired t-test. The spiritual nursing intervention was carried out through Hymn, Scripture, prayer, the therapeutic use of self over a period of three weeks. Results : 1) In general characters, men were a many more of the objects and the average age of the experimental and contrast group was 59.6, 55.9 respectively. The family of living together was $2{\sim}3$ members of most part. 2) There were not significant differences in the general, disease and therapeutic, religional characters between the experimental and contrast group. 3) The majority of the objects were cancer patients in disease and therapeutic characters(Experimental : 92%, Contrast : 95%). 4) After the spiritual nursing intervention state anxiety of the experimental group were remarkably lower than those of the contrast (t=-5.987, P=0.000). 5) Decreasing rate in the anxiety scores of before and post facto of the experimental group were remarkably lower than those of the contrast (t=6.237, P=0.000). Conclusion : The hospice patients who were offered spiritual nursing intervention became much lower than those who were not offered it in anxiety. Spiritual nursing intervention can be suited to field with one program of an effective that that relieved their anxieties. It is not only a very short time but has quite a little findings in part of spiritual nursing intervention. Therefore, further study in this field is necessary to concrete and substantial investigate in order to more and more increasing hospice patients in 21st century.

• Cross-Cultural Studies
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• v.50
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• pp.31-51
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• 2018

The concept of 'monsters' have become popular, again, in recent times. A number of 'monster narratives' that discuss monsters such as zombies, humanoids, viruses, extraterrestrials, and serial killers have been made and re-made in popular media. Noting such an interesting cultural context, this article attempts, first, to find out some essential prototypical elements of a monster narrative and, second, to relate it with a catastrophic narrative. Correspondingly, the word 'monster' has been used as a conceptual prototype category that denies universal and clear definition, which makes it as one of the most widely used and familiar subjects of the use of metaphor. The prototypical meanings of various monster figures can be converged on a certain creature of being in this way held out as bizarre, curious, and abnormal. The monster figure that surpasses existing normality is also connected to 'abjection,' such as something that is cast aside from the body such as the bodily functions seen in its associated blood, tears, vomit, excrement, or semen, and so on. Nevertheless, both the monster figure and abjection produce disgust and horror in the minds of ordinary spectators or readers of media using this metaphor to heighten excitement for the viewers. The abject characteristic of the monster figure also has something in common with the posthuman figure, meaning to apply to a category of inhuman others who are held outside of the normal category of human beings. In the similar vein, it is natural that the most typical monster figures in our times are posthuman creatures embodied in such forms as seen with zombies, humanoids, cyborgs, robots, and so on. In short, the monster figure includes all of the creatures and beings that disarray normalized humanist categories and values. The monster narrative, in the same sense, is a type of story that tells about others outside modern, anthropocentric, male-centered, and Westernized categories of thought. It can be argued that a catastrophic narrative, a literary genre which depicts the world where a series of catastrophic events demolish the existing human civilization, ought to be seen as a typical modern-day monster narrative, because it also discounts and criticizes normalized humanist categories and values as is the result of the monster narrative. Going beyond the prevailing humanist realist narrative that are so familiar with existing values, the catastrophic narrative is not only a monster narrative per se, but also a monstrous narrative which disrupts and reinvents currently mainstream narratives and ways of thinking.