• Economic and Environmental Geology
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• v.55 no.3
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• pp.295-307
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• 2022

We studied the Cretaceous Jeonggaksan Formation to determine depositional processes of pyroclastic density currents entering into the lacustrine environments. This formation is composed largely of sandstone-mudstone couplets and (tuffaceous) normally graded sandstones deposited in lacustrine environments, interbedded with two pyroclastic beds: welded massive lapilli tuff and normally graded lapilli tuff. The welded massive lapilli tuff (10 m thick) is composed of poorly sorted, structureless lapilli supported by a welded ash matrix. The normally graded lapilli tuff (4 m thick) is characterized by moderately to well sorted natures and multiple normally graded divisions in the lower part of the bed with internal boundaries. The contrasting depositional features between these lapilli tuff are suggestive of different physical characteristics and depositional processes of pyroclastic density currents in the lake. Overall poorly sorted and massive natures of the thick, welded massive lapilli tuff are interpreted to have been formed by rapid settling of pyroclastic sediments from highly concentrated and sustained pyroclastic density currents. In this case, the pyroclastic density currents were able to displace lake water from shoreline and the pyrolclastic density currents preserved their own heat except for frontal parts of the currents. As a result, welded textures can be formed despite entrance of pyroclastic density currents into the lake. The internal boundaries of the normally graded lapilli tuff reflect unsteady natures of the pyroclastic density currents at the time of the deposition and the pyroclastic density currents can not provide sufficient pressure to displace lake water. As a consequence, the pyroclastic density currents transformed into water-saturated turbidity currents, forming relatively well sorted, normally graded lapilli tuff.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.1
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• pp.93-114
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• 2023

Information extraction can facilitate the intensive analysis of documents by providing semantic triples which consist of named entities and their relations recognized in the texts. However, most of the research so far has been carried out separately for named entity recognition and relation extraction as individual studies, and as a result, the effective performance evaluation of the entire information extraction systems was not performed properly. This paper introduces two models of end-to-end information extraction that can extract various entity names in clinical records and their relationships in the form of semantic triples, namely pipeline and joint models and compares their performances in depth. The pipeline model consists of an entity recognition sub-system based on bidirectional GRU-CRFs and a relation extraction module using multiple encoding scheme, whereas the joint model was implemented with a single bidirectional GRU-CRFs equipped with multi-head labeling method. In the experiments using i2b2/VA 2010, the performance of the pipeline model was 5.5% (F-measure) higher. In addition, through a comparative experiment with existing state-of-the-art systems using large-scale neural language models and manually constructed features, the objective performance level of the end-to-end models implemented in this paper could be identified properly.

• Korean Journal of Optics and Photonics
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• v.34 no.1
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• pp.22-30
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• 2023

The use of segmented mirrors is one of the ways to make the primary mirror of a spaceborne satellite larger, where several small mirrors are combined into a large monolithic mirror. To align multiple segmented mirrors as one large mirror, there must be no discontinuity in the x, y-axis (tilt) and axial alignment error (piston) between adjacent mirrors. When the tilt and piston are removed, we can collect the light in one direction and get an expected clear image. Therefore, we need a precise wavefront sensor that can measure the alignment error of the segmented mirrors in nm scale. The tilt error can be easily detected by the point spread image of the segmented mirrors, while the piston error is hard to detect because of the absence of apparent features, but makes a downgraded image. In this paper we used an optical testing interferometer such as a Fizeau interferometer, which has various advantages when aligning the segmented mirror on the ground, and focused on measuring the axial displacement error of a segmented mirror as the basic research of measuring the piston errors between adjacent mirrors. First, we calculated the relationship between the axial displacement error of the segmented mirror and the surface defocus error of the interferometer and verified the calculated formula through experiments. Using the experimental results, we analyzed the measurement uncertainty and obtained the limitation of the Fizeau interferometer in detecting axial displacement errors.

• Korea Trade Review
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• v.43 no.1
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• pp.199-221
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• 2018

The internationalization of venture firms is of importance resulting from the increased opportunities as well as the entry barriers faced in this process. This study is to investigate barrier factors affecting Korean venture firms' internationalization. Among these factors, we measured relative weights using Analytic Hierarchy Process (AHP). Literatures regarding global firm's internationalization was reviewed, and barriers were classified environment, corporate and CEO barriers. Multiple variables were used in order to measure their relative significance. We surveyed executives of venture firms comprising two groups: first, 15 global venture firms, and secondly, gradually internationalizing firms. The two groups show contradictory results as environment barriers are the primary for born-global ventures and corporate barriers are the primary for gradually internationalizing ventures. Concerning corporate barriers, the lack of marketing capability is the highest barrier for both groups. The CEO barrier is the lowest for both groups. Regarding corporate barriers, gradually internationalizing ventures considers the risk of business as highest, whereas born-global ventures features the lack of R&D capacity as highest Results of this paper imply that firms should consider priority and sequential approaches in facing environment, corporate and CEO barriers.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.517-524
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• 2024

This study aims to train and implement a deep learning model for the fusion of website creation and artificial intelligence, in the era known as the AI revolution following the launch of the ChatGPT service. The deep learning model was trained using 3,000 collected web page images, processed based on a system of component and layout classification. This process was divided into three stages. First, prior research on AI models was reviewed to select the most appropriate algorithm for the model we intended to implement. Second, suitable web page and paragraph images were collected, categorized, and processed. Third, the deep learning model was trained, and a serving interface was integrated to verify the actual outcomes of the model. This implemented model will be used to detect multiple paragraphs on a web page, analyzing the number of lines, elements, and features in each paragraph, and deriving meaningful data based on the classification system. This process is expected to evolve, enabling more precise analysis of web pages. Furthermore, it is anticipated that the development of precise analysis techniques will lay the groundwork for research into AI's capability to automatically generate perfect web pages.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.240-246
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• 2024

Epithelioid angiosarcoma is a rare variant of angiosarcoma characterized by an epithelioid morphology that mimics carcinoma. Therefore, multicentric epithelioid angiosarcoma is easily misdiagnosed as bone metastasis from carcinoma and has an aggressive clinical course. Here, we present a rare case of a 61-year-old male with multicentric epithelioid angiosarcoma of the bone. Plain radiography, CT, and MRI revealed multiple osteolytic lesions in both femurs; some lesions showed soft tissue extension with cortical bone destruction. Interestingly, PET-CT revealed that the lesions were only distributed along the bones of the lower extremities, including the pelvic bones, femurs, and tibiae. Despite histological analysis initially suggesting metastatic carcinoma, after additional immunohistological staining, including that for vascular markers (CD31 and ERG), the final diagnosis was epithelioid angiosarcoma. A better understanding of the clinicoradiological features of this disease may help eliminate diagnostic confusion and provide better management.

• Information Systems Review
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• v.20 no.4
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• pp.59-78
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• 2018

With the advent of the various device types and marketing communication, customer's search and purchase behavior have become more complex and segmented. However, extant research on multichannel marketing effects of the purchase funnel has not reflected the specific features of device User Interface (UI) and User Experience (UX). In this study, we analyzed the marketing channel effects of multi-device shoppers using a unique click stream dataset from global online retailers. We examined device types that activate online shopping and compared the differences between marketing channels that promote visits. In addition, we estimated the direct and indirect effects on visits and purchase revenue through customer's accumulated experience and channel conversions. The findings indicate that the same customer selects a different marketing channel according to the device selection. These results can help retailers gain a better understanding of customers' decision-making process in multi-marketing channel environment and devise the optimal strategy taking into account various device types. Our empirical analyses yield business implications based on the significant results from global big data analytics and contribute academically meaningful theoretical framework using an economic model. We also provide strategic insights attributed to the practical value of an online marketing manager.

• Korean Circulation Journal
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• v.53 no.10
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• pp.693-707
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• 2023

Background and Objectives: Inherited arrhythmia (IA) is a more common cause of sudden cardiac death in Asian population, but little is known about the genetic background of Asian IA probands. We aimed to investigate the clinical characteristics and analyze the genetic underpinnings of IA in a Korean cohort. Methods: This study was conducted in a multicenter cohort of the Korean IA Registry from 2014 to 2017. Genetic testing was performed using a next-generation sequencing panel including 174 causative genes of cardiovascular disease. Results: Among the 265 IA probands, idiopathic ventricular fibrillation (IVF) and Brugada Syndrome (BrS) was the most prevalent diseases (96 and 95 cases respectively), followed by long QT syndrome (LQTS, n=54). Two-hundred-sixteen probands underwent genetic testing, and 69 probands (31.9%) were detected with genetic variant, with yield of pathogenic or likely pathogenic variant as 6.4%. Left ventricular ejection fraction was significantly lower in genotype positive probands (54.7±11.3 vs. 59.3±9.2%, p=0.005). IVF probands showed highest yield of positive genotype (54.0%), followed by LQTS (23.8%), and BrS (19.5%). Conclusions: There were significant differences in clinical characteristics and genetic yields among BrS, LQTS, and IVF. Genetic testing did not provide better yield for BrS and LQTS. On the other hand, in IVF, genetic testing using multiple gene panel might enable the molecular diagnosis of concealed genotype, which may alter future clinical diagnosis and management strategies.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.1
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• pp.71-82
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• 2016

Through literature review and on-site survey of Gimcheon Bangcho pavilion(芳草亭), the features of garden design(庭園意匠) including geographic conditions, landscape modeling of Nujeong(樓亭) and Jidang(池塘, Pond), and scenic interpretations in Nujeong Jeiyoung poetry(樓亭題詠詩) have been carefully researched and the findings are presented below. Bangcho pavilion is located in a village called Wonteomaeul, which belongs to the feng shui state of golden hairpin and floating lotus. It has long been the cultural hub of communication and social interactions among the villagers. The Head House of Jeongyanggong(靖襄公宗宅), the main house(本第) of the Yeonan Yi Clan(延安李氏), is about 150m away from Bangcho pavilion, an artistic space whose landscape modeling is of the form called Nujeong. The name 'Bangcho' reflects the noble man(君子)'s determination: "I yearn for the place where honey parrots fly and the fragrant grass grow." From the two story structure of the pavilion where there is an additional floor installed to the central ondol room by a four-sided subdivision door, one can detect the aspiration of the men for pursuing an open view. One can also observe the efforts in designing the room to be used for multiple purposes from a private place to an office for periodic publication of a family lineage document called "Garyejunghae(家禮增解)". Bangcho pavilion's main sight of interest is Mrs Choi's Pond(崔氏潭), the one and only garden structure that comprises the twin round island of square pond(方池雙圓島) among the existing Jidangs in Korea. In this special Jidang, there are two coexisting islands that represent a well thought out garden facility for symbolizing conjugal affection and unyielding fidelity between master and servent(主從). In addition, the three inflows and one outflow facing the Ramcheon valley is regarded as an ideal garden design optimized for performing the function of a village bangjuk which is the site for undercurrent creation and ecological reprocessing. At present, Giant pussy willow is the only circular vegetation identified in the area of Bangcho pavilion, although this plant species is about to wither away judging from the signs of decrepitude that seems to persist for two out of three weeks. The old pine tree that appears in the 1872 Jeiyoung poetry of Byeongseon Song(宋秉璿) no longer exists. Anjae(安齋) Jang Yoo(張瑠)'s "Eight Scenary on Bangcho pavilion(芳草亭八詠)" and its expansive reproduction "Ten Scenary on Bangcho pavilion(芳草亭十景)" from Gwagang(守岡) Lee Manyoung(李晩永) depict vividly the pastoric scenery of an idyll(田園景) that stretches throughout the natural and cultural landscape of the province of Gimcheon and Guseong surrounding the Bangcho pavilion. The Bangcho pavilion sutra aims to establish Bangcho pavilion and the village of Wonteomaeul as the centre of microcosmos by dividing and allocating its scenic features according to the four seasons and times(四季四時), the eight courses(八方) and the meteorological phenomena, and it is the incarnation(顯現) of landscape perception upon the Byeol-seo Scenic site of Bangcho pavilion, the cultural hub of the region.

• Journal of Science Education
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• v.42 no.1
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• pp.27-48
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• 2018

The purposes of this study are to derive suggestions and implications to improve the continuity of Korean Science & Practical Arts (Technology Home Economics) curricula through international comparative analysis with focus on the science curricula or standards in five countries (Canada, New Zealand, Singapore, the United States, Korea). Original documents of the national curriculums or standards of each country collected from NCIC comparatively analyzed the big concepts of the 'system' and 'energy' based on features of related components of curriculum contents, vertical, and lateral connectivity. The results indicated that the big concepts of systems and energy were used internationally to consider the curriculum continuity. In most countries, the big concept of system was used as a framework to integrate science with technology or other contents. In particular, it was also utilized to strengthen vertical and lateral connectivity in earth science and space science contents area. In the comparison of countries for the system as the big concept, New Zealand focused interrelationship between system and human activities, systems' interaction, levels and features of system concept for the linkage between grades and subjects on the basis of level. In the case of Canada and Singapore, science and technology are combined to strengthen contents' connection. However, the revised 2015 curriculum has a lack of continuity and sequence because the concepts of system and energy were concentrated on a specific grade and contents' area. The curriculum was not developed systematically for multiple grades according to their levels. In conclusion, Korean science curriculum requires sufficient understanding of students' learning and research on learning progressions and curriculum continuity. In addition, it is very important to constitute the curriculum based on the vertical and lateral connectivity in order to improve science education and to foster students' key competencies and abilities.