• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.563-569
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• 2021

With the launch of Compact Advanced Satellite 500 series of various characteristics and the operation of KOMPSAT-3/3A, uses of high-resolution satellite images have been continuously increased. Especially, in order to provide satellite images in the form of ARD (Analysis Ready Data), various pre-processing such as geometric correction and radiometric correction have been developed. For pre-processing of high spatial satellite imagery, auxiliary information, such as solar zenith, solar azimuth and offnadir angle, should be required. However, most of the high-resolution satellite images provide the solar zenith and nadir angle for the entire image as a single variable. In this paper, the solar zenith and offnadir angle corresponding to each pixel of the image were calculated using RFM (Rational Function Model) and auxiliary information of the image, and the quality of extracted information were evaluated. In particular, for the utilization of pixel-based solar zenith and offnadir angle, pixel-based auxiliary data were applied in calculating the top of atmospheric reflectance, and comparative evaluation with a single constant-based top of atmospheric reflectance was performed. In the experiments using various satellite imagery, the pixel-based solar zenith and offnadir angle information showed a similar tendency to the auxiliary information of satellite sensor, and it was confirmed that the distortion was reduced in the calculated reflectance in the top of atmospheric reflectance.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.237-245
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• 2022

This study examines the social discourse on the characteristics of the learning community in the untact era, and discusses the directions that learning communities for children could explore and consider in the pandemic situation and beyond. For this purpose, big data for one year, from January 20, 2020 to January 20, 2021, were collected through internet portal sites (includingincluding Google News, Daum, Naver and other News surfaces), using two keywords "untact" and "learning community", and analyzed by employing a word frequency and network analysis method. The analysis results show that several important terms, such as 'village education community', 'operation', 'activity', 'corona 19', 'support', and 'online' are closely related to the learning community in the untact era. The findings from this study also have implications for developing the learning community as an alternative model to fill the existing gaps in public care and education for children during the prolonged pandemic and afterwards. In conclusion, the study findings highlight that it is meaningful to identify key terms and concepts through word frequency analysis in order to examine social trends and issues related to the learning community.

• Journal of Korean Library and Information Science Society
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• v.53 no.3
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• pp.47-72
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• 2022

This study identified the current status and degree of awareness of specialized libraries through a survey of public library employees in relation to specialized library projects supported and promoted by the Ministry of Culture, Sports and Tourism and local governments and sought policy directions to revitalize specialized libraries in the future. As a result of the analysis, local (region) was the most common specialized topic, but there were many places that selected topics according to the interest of policymakers. In the case of the data, less than 5% of the total books are specialized, and specialized subject-related programs account for more than 20% of the total library programs, providing an average of three to four programs, and operating personnel generally do not deploy dedicated librarians. When specialized topics meet regional characteristics, when there are separate buildings or specialized rooms, there are two to three dedicated librarians, at least 15% of specialized books, and more than five to six programs, the user's awareness and satisfaction were higher. In order to revitalize specialized libraries, it is necessary to secure additional books, organize differentiated programs, arrange exclusive librarians, provide subject-specialized education through the Korea Library Association and regional representative libraries, develop and distribute specialized and target service manuals, and secure a sufficient budget.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.149-155
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• 2023

Photovoltaic power generation is the most familiar power generation facility among new and renewable energies, and its supply began to expand about 10 years ago, and at this point, interest in solutions and technologies for system maintenance management is increasing. In particular, it is necessary to take measures to maximize the overall efficiency of the solar power generation system, whether or not there is an abnormality in the solar power generation system, and when to replace parts. The PV inverter, one element of the photovoltaic power generation system, is a power conversion system that relies on power switching devices, and DC-Link capacitors are used according to the configuration of DC/DC converters and DC-AC inverters. These DC capacitors also affect system safety (Safety) through renewable energy facilities due to the decrease in power generation of PV inverters, power loss, and increase in harmonics (THD, total distortion of AC output current) due to aging and deterioration due to long-term use. factors can be analyzed. Therefore, in this paper, the PV inverter operating characteristics according to the DC capacitor capacity state currently operating in the photovoltaic power generation system were considered, and research contents were proposed to secure the safety and reliability of renewable energy facilities.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.57-63
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• 2023

The external weather conditions including temperature and wind speed in the Saemangeum reclaimed land is different from that of the inland, affecting the internal environment of the greenhouse. Therefore, it is important to select an appropriate covering material considering the insulation effect according to the type and characteristics of the covering material considering the weather condition in the Saemangeum reclaimed land. A hexahedral insulation chamber was designed to evaluate the insulation efficiency of each glass-clad material in the outside weather condition in reclaimed land. In order to evaluate the insulation effect of each covering material, a radiator was installed and real-time power consumption was monitored. 16-mm PC (polycarbonate), 16-mm PMMA (polymethyl methacrylate), 4-mm greenhouse glass, and 16-mm double-layered glass were used as the covering materials of the chamber. In order to understand the effect of the external wind directions, the windward and downwind insulation properties were evaluated. As a result of comparing the thermal insulation effect of each greenhouse cover material to single-layer glass, the thermal insulation effect of double-layer glass was 16.9% higher, while PMMA and PC were 62.5% and 131.2% higher respectively. On average the wind speed on the windward side was 53.1% higher than that on the lee-wind side, and the temperature difference between the inside and outside of the chamber at the wind ward side was found to be 52.0% larger than that on the lee ward side. During the experiment period, the overall heating operation time for PC was 39.2% lower compared to other insulation materials. Showing highest energy efficiency, and compared to PC, single-layer glass power consumption was 37.4% higher.

• Korean Journal of Environment and Ecology
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• v.10 no.2
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• pp.211-239
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• 1997

The flora of Oesorak in the Soraksan National Park including Chombongsan(Mountain) and Kwanmobong(Peak) were surveyed from February to August, 1996. These areas have very rich and diverse flora;620 taxa with 89 families, 321 genera, 526 species, 2 subspecies, 89 varieties and 3 forms in the Oesorak, 404 taxa with 251 genera, 350 species, 1 subspecies, 51 varieties and 2 forms in the Chombongsan(Mountain), 286 taxa with 206 genera, 233 species, 1 subspecies, 50 varieties and 2 forms in Kwanmobong(peak). The Oesorak had very distinct floristic characteristics such as the wild habitats of Asarum maculatum(Aristolochiaceae) and Ilex macropoda(Aquifoliaceae). In the phyorgeographical point of view, the six species such as Sapium japonicum (Euphorbiaceae), Euphorbia joldini(Euphorbiaceae), Ilex macropoda (Aquifoliaceae), Styrax japonica (Styracaceae), Carex sideros ticta (Cyperaceae) and Asarum maculatum (Aristolochiaceae) were naturalized into this region, while the 17 taxa such as Abies neprolepis(Pinaceae), Pinus pumila(Pinaceae), Thuja koraiensis(Cupressaceae), Allium senescens(Liliaceae), Lilium distichum(Liliaceae), Saxifraga punctata(Saxfragaceae), Rosa marretii(Rosaceae), Bupleurum euphorbioides(Umbelliferae), Androsace cortusaefolia (Primulaceae), Peducularis mandshurica(Scrophulariaceae) and Leontopodium coreanum (Compositae) were distrivuted to this region. The colonizing weedy species such as Ixris repens (Compositae) were distributed to this region. The colonizing weedy species losa(Labiatae) and Rosa rugosa(Rosaceae) were naturalized into ca. 900m at sea level mainly due to the sand soil from the seashore. Mountain roadbed is susceptible than other areas to the slippery road problems, due largely to snow and rain, particularly during winter. Sand soils from seashore are utilized to minimize this slip in traffic operation.

• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.199-214
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• 2022

A relative important analysis was conducted to determine what factors are required for port selection in Mokpo New Port and what needs to be addressed first in order to expand automobile and steel cargo handling. The port selection factors of Mokpo New Port were classified into 4 major and 13 intermediate categories, and AHP analysis was used. As a result, items such as 'port facilities', 'accessibility to international ports', 'port facility usage fees', and 'connectivity with neighboring cities/ports' were evaluated as important. The respondent groups were divided into shipowner and shipper, port operator and stevedore, and public official, and an analysis of variance (ANOVA) was conducted to verify if there was a difference in perception between the groups. As a result, shipowner and shipper, port operator and stevedore were similar, but there was a difference from public official group. Shipowner and shipper, port operator and stevedore with similar response characteristics were classified into the 'port practitioner' group, and public official were classified into the 'port policy maker' group, and the difference in perception between the group was tested. Therefore, there were differences in some major category items, and even in the intermediate category items such as 'possession of adjacent hinterland industrial complex', 'cargo equipment', '24-hour port operation', 'inland transportation cost', 'accessibility to international ports', 'marketing and incentives' with statistical. In other words, the 'port practitioner' group evaluated items that can increase cargo creation and handling productivity as important whereas the 'port policy maker' group considers port development and policies such as port infrastructure, connectivity with other ports, and incentive support items are more important.

• The Korean Journal of Archival Studies
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• no.75
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• pp.177-212
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• 2023

Private archives are an important indicator of understanding a society that contains various memories, the lives and experiences of members, daily lives, morality, and values. Recently, as diversity has emerged as an important value in Korean society, a number of individuals and communities have been appeared based on different bases and purposes, and the contents, types, and categories of private archives produced from their voluntary activities have also diversified. These private organizations and communities are potential targets for producing and holding private archives, but most of them do not have the minimum infrastructure or system for management of archives, and the foundation for management of archives is weak only to be supported with the voluntary will and activities of the private sector. Therefore, there is a need for a plan to support activities to manage archives suitable for each organization's level while respecting the unique characteristics and methods of the private sector within the national management system of archives. In addition, since it is difficult to solve all issues related to management of archives in the private sector with only a small number of process topics, a cooperative system should be established to sustain activities to manage archives on its own through networks between private sectors. In this study, we intend to propose a 'private archives information network platform (hereinafter referred to as a platform)' as a way to establish a communication and network foundation between private sectors and share resources with each other. Based on the results of analysis of cases of building network between private sectors and expected user requirements, we would like to establish a vision and target model of the platform and discuss ways to continuously operate the platform.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1352-1358
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• 2009

As the demand for a convergence between construction technologies and IT is on the rise, as seen in the visualization of U-City construction, studies on the ways in which IT in should be utilized in the building and construction field have been continuously and actively performed. However, there has been almost no development of standardized technology criteria relating to the life cycle of a building (planning, design, construction, and maintenance). That is, there are almost no examples of efforts made to combine construction technology and IT in a fundamental way, considering the environment, the facility, its spatial characteristics, engineering, materials, and structure, aspects that are commonly required not only for interior spaces but also for exterior construction of U-City. Despite the fact that a state-of-the-art infrastructure has been built, and the competency of users with the cutting-edge technology, composite studies on technologies, facilities, services and spaces are still lacking, and basic research on the composite operation method including compatibility and linkage between facilities and services within a U-City has been insufficient as well. It is generally known that by fusing IT with construction technologies, the total period of construction taken can be reduced and construction expenses can be curtailed, while construction quality can be improved. For this reason, it is vital to prepare a standardized base to connect cutting-edge IT with the construction technologies. In preparing such a base, the most urgent issue is to develop standardized technology criteria. The ultimate objective of this research is to establish the technological criteria system required to apply construction-IT fused technologies to U-Cities, and to develop the technological criteria for the design, construction and maintenance of the U-Cities. This paper, whose objective is to establish development strategies for construction-IT fused technologies by way of analyzing the criteria for conventional construction projects, the necessity of criteria for construction-IT fused technologies, and the current status of U-Cities' development, is the underlying research for this purpose. The strategies established are expected to be utilized in establishing the system of criteria for construction-IT fused technologies, and to contribute to a knowledge base in the construction-IT field. In addition, based on the strategies established, criteria for construction-IT fused technologies, such as design criteria and construction standards, will be developed, and by applying these criteria and standards, the ultimate objectives of U-Cities, which are the enhancement of urban competitiveness and the satisfaction of residents, will be attained

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.191-201
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• 2023

The provision of onboard Internet services is recognized as one of the measures to enhance the appeal of seafarers and improve seafarer welfare. This study aims to investigate the influence of seafarers' leisure activities using the Internet on shipboard culture. Shipboard culture was examined using Hofstede's cultural dimensions theory. An empirical analysis was conducted on crewmembers regarding their Internet-based leisure activities and the shipboard culture. As a result, it was observed that sociability activities through the Internet while onboard significantly influenced power distance, uncertainty avoidance, and long-term orientation. The investigation of shipboard culture revealed uncertainty avoidance, masculinity, and long-term orientation, along with low power distance and individualism cultures. In addition, an analysis of shipboard culture according to seafarers' characteristics showed significant differences in certain shipboard cultures based on seafarers' attributes.