• Korean Journal of Optics and Photonics
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• v.14 no.6
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• pp.669-673
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• 2003

We fabricated a buried-ridge waveguide laser diode (B-RWG LD) which has more advantages for obtaining lateral single mode operation on the same ridge width and for the planarization of the device surface, compared to the conventional RWG LD. In this LD, the difference of the lateral effective refractive index can be controlled by the thickness of the InGaAsP layer which is grown on the active and the p-InP layers. The InGaAsP multiple quantum well was grown on a n-InP substrate by the CBE. The buried ridge structure was formed by selective wet etchings, followed by liquid phase epitaxy methods. The fabricated LD with the ridge width of 7 ${\mu}{\textrm}{m}$ showed a linear increase of the optical power up to 20 ㎽ without any kinks and a saturated output power of more than 80 ㎽. By measuring the far field pattern, we demonstrate that LDs with the ridge widths of 5 ${\mu}{\textrm}{m}$ and 7 ${\mu}{\textrm}{m}$ were operated in a lateral single mode up to 2.7I$_{th}$ and 2.4I$_{th}$, respectively.ely.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.173-192
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• 2021

The purpose of this study is to analyze the previous research on geological fieldwork from 2000 to 2020, examine the tasks that have been focused on, and suggest directions and implications for future geological fieldwork research. The data was conducted for the thesis searched on ScienceON and RISS in relation to geological fieldwork and journals listed in the Korean Citation Index(KCI), and the study title was analyzed using the semantic network analysis. For analysis, the data that had been pre-processed was visualized as a network by semantic network analysis, and frequency and centrality were analyzed. The centrality analysis was based on degree centrality and eigenvector centrality, and all analyzes were performed by dividing the entire study period into four periods: 2000-2005, 2006-2010, 2011-2015, and 2016-2020. As a result, research on geological fieldwork focused more on the development of geological field courses, and in particular, jeju island was actively discussed as a learning site. Also, the study was conducted on students rather than teachers, and among them, high school students showed high frequency and centrality. In addition, it can be seen that studies on the educational effect of geological fieldwork were discussed, either in connection with programs such as STEAM, free-semester program, or indirect geological fieldwork methods such as web, flash panorama, and 3D. This study is meaningful in that it suggests the direction of future research by looking back on the research on geological fieldwork that has been done so far.

• Journal of Life Science
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• v.31 no.10
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• pp.960-968
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• 2021

Since microalgae research started on late 18 century, they have been recognized as one of the most important bioresources used in bioindustry. Owing to the large efforts paid to industrial application of this microorganisms, their importance on food/feed and bioactive compounds has been further extending into the environmental research areas including alternative energy resources, mitigation of the carbon emission, and waste-water treatment. However, despite the importance on their industrial application, the fundamental research field related to the long-term preservation of microalgae culture has not received much attention. However, a less labor intensive and cost-efficient preservation technology enabling biologically active and stable microalgae-culture provides a key success factor in the biotechnological application. Therefore, this study investigated various cutting-edge microalgae cryopreservation technologies currently developed so far, mainly targeting Chlorophyta, which occupies the largest taxon in the classification system of microalgae. In addition, for the development of successful cryopreservation technique, the key factors such as temperature control effect and preservative effect during cryopreservation of microalgae culture were investigated. In addition, the problems with current preservation technology that is being used in Korean domestic biological resource banks and the international microalgal resource banks are described. According to our investigation, currently no standard method for long-term preservation of microalgae is available due to their various morphological and physiological characteristics. To overcome such issues, much more efforts on fundamental research area on the identification of specific biomarker used for microalgae taxonomical classification and further systemic approaches based on strain-specific cryopreservation methods needed.

• (The) Research of the performance art and culture
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• no.36
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• pp.783-837
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• 2018

This study examines the lives and the performances of the people who participated in Songpa Sandae-nori(a korean traditional mask dance drama) before and after the designation as cultural heritage, and reviews the changes and the inheritance patterns of the mask dance which appeared in the lives of the performers. Chapter 2 reviewed previous debates about the derivational theory and the players of Songpa Sandae-nori before the flood in 1925, and discussed on awareness and the characteristics of the performers found through the review. Then the study went on to the inheritance patterns of the drama before the designation, focusing on the figures of Dolmari(a name of village in Songpa, Seoul) players who led the stage after 1925. As a result, the missing part of the activities and the lives of Dolmari performers have been more clearly identified, especially about Lee Beomman, Yeo taesan and Eum Joongeun(the main performers of Songpa Sandae-nori). Chapter 3 is about the inheritance patterns of the cultural heritage after the designation, and Heo Hoyoung was the main focus of the discussion. The researches so far have admitted his great contributions to the designation of cultural asset, although they have not proved how. After investigating various records and combining the testimonies of his students and locals, Heo Ho-young was found that he did not only gave plays of Songpa Sandae-nori but also actively engaged in the field of various traditional arts. Furthermore, jokes, dances, and masks left by him are considered to be evidences to reassess his performances.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.133-139
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• 2019

A Convergence Research Study of Southern Fujian Region in China during the Song Dynasty analyzing the Export of Ceramics During the Song Dynasty in China ceramics made in the Southern Fujian (also known as Minnan) region were exported to different countries in Southeast Asia including the Philippines, Thailand and more. They were even exported to Korea, Japan and through trade they traveled as far as Africa. Ceramics was one of the three main sea route export item of China at the time and there were active commercial trading between Korea as well as other countries, enabling ceramics to develop rapidly. The harmonious reciprocal relationship between the geographical, political, cultural, economical characteristics of Southern Fujian enabled a unique type of celadon ware widely recognized to develop. Ceramics of this region is one of a kind in terms of history when we relate it to research on integrating different elements. It suggests a unique convergence of culture when we study its forms and its industrial characteristics. The study attempts to analyze the influence of geography, politics, economy and culture on the different phenomena found in ceramics. Different paradigms associated with changes of environment reflect on continued development in the field of ceramics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.967-977
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• 2018

The problems of lack of skilled worker and poor productivity at the construction site continue to be raised, and the introduction of construction automation as one of the solutions to this has been considered. The development of various types of equipment and systems has been carried out, especially for earthwork operations with multiple construction equipment. However, the level of commercialization of developed equipment or systems is very limited. Although the single-product type of earthwork equipment has been applied to the site, the integrated type of earthwork system is still in the field testing stage. Considering these constraints, the limited budget and research period, a strategy is needed to identify which technology areas and core technologies should be developed first. In this study, the technology areas and detailed core technologies that are essential for the development of earthwork systems at the level of commercialization are set and the priority of development is determined. In addition, the earthwork system that has been developed so far is analyzed and the detailed development direction is presented based on it. The findings can be used for a decision making to set the priority for core technologies that should be developed first in the limited budget and period.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.12
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• pp.485-496
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• 2018

So far, the deep learning, a field of artificial intelligence, has achieved remarkable results in solving problems from unstructured data. However, it is difficult to comprehensively judge situations like humans, and did not reach the level of intelligence that deduced their relations and predicted the next situation. Recently, deep neural networks show that artificial intelligence can possess powerful relational reasoning that is core intellectual ability of human being. In this paper, to analyze and observe the performance of Relation Networks (RN) among the neural networks for relational reasoning, two types of RN-based deep neural network models were constructed and compared with the baseline model. One is a visual question answering RN model using Sort-of-CLEVR and the other is a text-based question answering RN model using bAbI task. In order to maximize the performance of the RN-based model, various performance improvement experiments such as hyper parameters tuning have been proposed and performed. The effectiveness of the proposed performance improvement methods has been verified by applying to the visual QA RN model and the text-based QA RN model, and the new domain model using the dialogue-based LL dataset. As a result of the various experiments, it is found that the initial learning rate is a key factor in determining the performance of the model in both types of RN models. We have observed that the optimal initial learning rate setting found by the proposed random search method can improve the performance of the model up to 99.8%.

• Korean Journal of Heritage: History & Science
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• v.42 no.4
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• pp.4-19
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• 2009

Though admitting that, in light of the recent archaeological trend, the excavation on relics of Sam-gama (a sort of kiln steaming the hemp) is increasingly reported, little efforts by far have been made not only to restore its traditional structure design but also to research hardly the change of hemp-steaming technologies in ages. In this regard, this paper shows the exploration of structural method and design as well as operability with regard to Sam-gut, traditional hemp-processing equipment that was recently reconstructed in Jungsun, Kangwon Province. Samgut, generally positioned at the waterside area, is an traditional device for steaming hemp to get bast fibers from the raw material of hemp, principally consisting of HWA-JIP(fire-place) to obtain steams by feeding fire ad Mong-got(boiling chamber) to make the hemp steamed after stacking. More specifically, thick round-logs were piled at the bottom of Hwajip prior to stacking stones around its circumferential area. When the timber positioned below gets burned with high temperature to heat stones existing in the upper side, waters then poured onto it after laying a bundle of grass and soil up to the boiled stones. If so, there generates hot vapor, which is conveyed to Monggot to steam the hemp. Functionally, it is of outstanding importance that Samgut is capable of producing high-temperature water vapors instantaneously under the intensive manpower, thus being constructed achievable for those purposes. The Samgut made by digging the ground is an instant facility that is closed after use. The remains, which were used to generate higher thermal power for steaming hemp, make it hard to excavate the historic traits because there left little vestiges in the soil, which means keen attention must be paid to find out the trace of Smgama relics. Future research stall be focused on collection of broader data regarding Samgut including technological review in extracting bas fibers from the hemp.

• Convergence Security Journal
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• v.17 no.5
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• pp.41-47
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• 2017

The Marine Environment Observation Information System supplies oceanographic information elements such as water temperature, chlorophyll, float, etc. based on satellite images to consumers. The data produced by the Korean marine environmental observatories are located in the coastal areas of Korea. But if the range is too far from a particular area of interest, due to distance or spatial constraints, the accuracy and up-to-dateness of the data can not be relied upon. Therefore, it is necessary to perform fusion and complex operation to solve the difference between the field observation and the marine satellite image. In this study, we develop a system that can process marine environmental information in the user's area of interest in the form of layered character (numeric) information considering the readability and light weight rather than the satellite image. In order to intuitively understand satellite image information, we characterize (quantify) the marine environmental information of the area of interest and we process the satellite image band values into layered characters to minimize the absolute amount of transmitted / received data. Also we study modular location-based interest information service method to be able to flexibly extend and connect interested items that diversify various observation fields as well as application technology to serve this.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.738-752
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• 2021

This study was to applied QIMS(Qualitative Interpretive Meta-Synthesis) which was newly introduced in the field of social science recently to explore the client violence experience and coping in the social workers in a new way and in depth. The integrated analysis of the results of qualitative individual studies published in Korea so far has resulted in abundant results with accumulated knowledge and synergistic understanding paths of existing research results, and the limitations of qualitative research have been overcome. Eight published papers from 2013 to 2020 were included in the final analysis, and a total of 85 social workers analyzed the statements. The newly important themes created through the process of reducing the scope of data and the repetition of theme extraction and integration were divided into four categories: (1) violence and pain that can not be removed, (2) duality experienced as a result of occupation, (3) continuous attempts to change, (4) manifestation of sense of duty and job meaning. Based on the results of the integrated themes derived from this study, this study aims to present practical and policy alternatives to the prevention and coping of client violence experienced by social workers in various social welfare practice fields.