• Asia-Pacific Journal of Business
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• v.15 no.1
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• pp.335-352
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• 2024

Purpose - Low fertility rate is a serious problem, and this study analyzes factors affecting total fertility rate using panel data from 16 metropolitan cities and provinces in Korea from 2000 to 2022. Design/methodology/approach - Estimating the SAR model considering the weak cross-sectional dependence that exists in variables related to the regional total fertility rate, and using the DKSE estimation method considering the strong cross-sectional dependence. Findings - Estimation results considering weak and strong cross-sectional dependence were similar, confirming the robustness of the results. Female labor force participation rate has a positive effect on total fertility rate, and employment rate has no effect. However, the interaction term is a negative (-) sign. Crude marriage rate has a positive effect on total fertility rate, and apartment price has a slightly positive effect. Environmental factor has no effect, and policy factor has a negative effect. Research implications or Originality - In order for an increase in the female labor force participation rate to lead to an increase in the total fertility rate, qualitative improvements in female employment must be made. Financial investment policies for childbirth must increase their effectiveness. The problem of low fertility rate requires not only population policy but also social, economic, cultural, environmental, and policy conditions to be considered.

• Journal of Radiation Industry
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• v.17 no.2
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• pp.191-197
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• 2023

Abstract KOMAC(Korea Multi-Purpose Accelerator Complex, KAERI) has been operating a 100 MeV proton accelerator and is going to produce ⁶⁸Ga isotope which is useful for diagnosis of cancer. So, it is necessary to develop a transport container for radio-activated targets. In this study, we carry out shielding analysis and structural analysis for the radio-activated target transport container using simulation programs. According to the Type A standard, the transport container includes an inner container and an overpack container. The main material of inner container is lead, and the shape is cylindrical with diameter of 152mm, height of 142mm and weight about 29 kg. It is planned to verify the possibility of field application through production of the transport container prototype in the future.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.399-406
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• 2024

This research paper explores the integration of Unmanned Aerial Vehicle (UAV)-based remote sensing survey methods, specifically LiDAR and photogrammetry, into the measurement and payment processes of beach fill construction projects managed by the U.S. Army Corps of Engineers (USACE). The primary objective is to evaluate the feasibility, accuracy, and cost-effectiveness of UAV technology in contrast to traditional topographic and hydrographic survey methods. The methodology includes a comprehensive literature review, case studies, accuracy standard assessments, and a detailed cost comparison between conventional and UAV-based survey techniques. The findings reveal that UAV-based remote sensing can offer significant improvements in terms of efficiency and cost savings. UAVs are capable of capturing large data volumes quickly with reduced manpower and equipment needs. However, the accuracy of UAV surveys is contingent upon environmental conditions and the proper staging of control points. Moreover, the initial investment and operational costs of UAV equipment are substantial and warrant further analysis. The paper argues for flexibility in measurement and payment methodologies during the project design phase to accommodate UAV technology. While environmental conditions may occasionally necessitate traditional survey methods, the study suggests that regions like the Florida Peninsula, with clearer water and more favorable weather, are particularly well-suited for the implementation of UAV-based surveys. The significance of this study lies in its potential to guide future beach fill construction projects, promoting more efficient and cost-effective survey methods while adhering to accuracy standards and environmental considerations.

• Journal of Korea Trade
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• v.25 no.2
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• pp.75-94
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• 2021

Purpose - This article will take the Korean manufacturing industry as an example to estimate Korea's global value chain status from the perspective of overall and sub-industry, hoping to provide a theoretical reference for Korean manufacturing to climb the global value chain. Design/methodology - Based on the WIOD data. The data is calculated by using MATLAB (2014a) coding. The data for 6 sectors are classified according to the International Standard Industrial Classification revision 3 (ISIC Rev. 3), the WIOD data are used to calculate and compare the position, participation and dynamics of the Korea, China and USA' manufacturing industry in the 1995-2016. Findings - The empirical results supported conclusions of the theoretical model. In the Korean GVC of electrical and optical sector, while stronger forward linkages than backward linkages to GVC are advantageous for an average advanced country, the benefits of downstream tasks are pronounced for non-advanced countries. And proved the correlation for an index to capture a country's upstream position or downstream position, it makes sense to compare that Korea's exports of intermediates in the same sector that are used by China and USA. Originality/value - The first is to re-examine the characteristics of South Korea's participation in global value chains under a more systematic and accurate theoretical framework, which provides a new empirical reference for related research; the second is to content covers of the manufacturing 6 sectors, so as to more completely describe the characteristics of Korean manufacturing's participation in global value chains; The value of this paper is providing empirical evidence of the effect of Korea's the GVC of manufacturing sectors. In the GVC of 6 sectors, first three have a higher position in the value chain and are in the upper middle and upper reaches of the GVC. The latter two have a low GVC position index, which has become the main sector that pulls down the overall position of Korea's manufacturing industry.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.4
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• pp.629-639
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• 2024

CHAM is designed with an emphasis on encryption speed, considering that in the ISO/IEC standard block cipher operation mode, encryption functions are used more often than decryption functions. In the superscalar architecture of modern general-purpose processors, different ordering of operations can lead to different processing speeds, even if the computation configuration is the same. In this paper, we analyze the implementation efficiency and security of CHAM-like structures, which rearrange the order of operations in the ARX-based block cipher CHAM, for single-block and parallel implementations in a general-purpose processor environment. The proposed structures are at least 9.3% and at most 56.4%efficient in terms of encryption speed. The security analysis evaluates the resistance of the CHAM-like structures to differential and linear attacks. In terms of security margin, the difference is 3.4% for differential attacks and 6.8%for linear attacks, indicating that the security strength is similar compared to the efficiency difference. These results can be utilized in the design of ARX-based block ciphers.

• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.186-199
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• 2016

The shoe last which is the framework for the shoemaking is intensively combined with the 3D data and technologies. International shoe companies have already commercialized 3D printing technology in producing the shoe, but domestic shoe companies are still in their early stages. This study used the 3D scanning, 3D modeling and 3D printing of the high-technology to make the shoe last. This 3D producing processes should be helpful in building competitiveness in domestic shoe industry. The 3D foot scanning data of men in 30s(n=200) were collected in SizeKorea(2010). The basic statistics, factor and cluster analysis were performed. They were categorized in 3 groups by 3D foot measurement data, and the standard models were selected in each group. The cross sections in XY, YZ and XZ planes sliced from 3D scan data of the standard model were used in the sketches of the 3D shoe last modeling. The 3D shoe last was modeled by Solidworks CAD and printed by MakerBot Replicator2; a desktop 3D printer. This research showed the potential for utilization of 3D printing technology in the domestic shoe industry. The 3D producing process; 3D scanning, 3D modeling and 3D printing is expected to utilized widely in the fashion industry within the nearest future.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.408-413
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• 2018

In this paper, the particle size, bulk density, friction coefficient and angle of repose were measured for the automatic processing of solar salt, which was classified with 5 levels of moisture content (16.5, 13.2, 8.2, 4.9, 3.7%). Average diameter was 1.98~1.60mm according to moisture content, and bulk density increased with increasing moisture content. As a result of measuring the coefficient of dynamic friction, the maximum value was shown in the stainless steel plate according to the material, and ABS plate and acrylic plate were lower in the order. Movement occurred at the moisture content of 8.2% or less, and the empty angle of repose was increased and the filling angle of repose was decreased as the moisture content increased.

• The Journal of Industrial Distribution & Business
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• v.9 no.6
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• pp.37-47
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• 2018

Purpose - In this study, the safety related tasks for low cost carriers' were examined and measures to improve them were suggested. As the air demand increases rapidly, number of passenger has mushroomed in Korea and in order to keep with the demand low cost carriers have played a role. However, low cost carriers' safety related tasks are not reliable level so far. Thus, in this study, the low cost carriers' current situations in terms of safety are investigated, especially regarding how well the ICAO's new safety policies are applied. Research design, data, and methodology - The results of the Ministry of Land, Infrastructure and Transportation' investigation are introduced and field study results are analysed. Current status of retaining experts, staffs, administrators in terms of aviation safety tasks of low cost carriers is compared to those of major airliner and low cost carriers' aviation safety culture is also analyzed by examining the systems and questioning staffs. Especially the culture regarding aviation safety is very important because the culture surrounding the safety tasks plays a major role in every respect of conducting the tasks. Results - Overall the current status of low cost carriers' aviation safety tasks is below standard. Especially retaining experts and staffs is basically below the required level. Also, system and organization to conduct safety tasks are not satisfactory. In particular, aviation safety culture is not settled to operate appropriately. Conclusions - The International Civil Aviation Organization (ICAO) and member states are continuing to launch new safety policies in response to the surging demand for air travel worldwide. The most urgent and important issue among the various safety policies is to reduce air accidents. In order to reduce the number of accidents, ICAO decided to reduce the number of accidents by using the Reactive Safety Management. ICAO has to ensure that each member country can implement proactive safety management for aviation safety. A safety management system (Safety Management System) is a system in which each member state implements a fulfillment standard. The current situation and problems of the safety management system for each airline are suggested and proposed for improvements.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.252-258
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• 2018

A larger energy consumption and concentration of population induced green house gas glowing and heat island effect in the urban space. Roof green system was a effect method to reduce green house gas and heat concentration in the city. Therefore, construction of this system was increasing. Most of lightweight soil used in roof green system was perlite, but this caused dust and skin disease. So it needed to develop another new lightweight soli for roof green system. Meanwhile, a thermoelectric power plant generated bottom ash as a by-product. According to previous research, bottom ash could be used for artificial lightweight soil with 60 wt% of mixing rate. But this study was proceed to develop a artificial lightweight soil using bottom ash with higher mixing rate by 65 wt% and different organic ingredients. First, physical and chemical properties of bottom ash was investigated. Then test according to landscaping design standard was proceeded for various artificial lightweight soil mix types using bottom ash, bark, compost and coco peat. As a result, the artificial lightweight soil with 65% of bottom ash, 30% of bark and 5% of compost was suitable for low and middle range of soil standard.

• Journal of the Korean Geotechnical Society
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• v.38 no.3
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• pp.35-42
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• 2022

The N-value from the Standard Penetration Test (SPT), which is one of the representative in-situ test, is an important index that provides basic geological information and the depth of the bearing layer for the design of geotechnical structures. In the aspect of time and cost-effectiveness, there is a need to carry out a representative sampling test. However, the various variability and uncertainty are existing in the soil layer, so it is difficult to grasp the characteristics of the entire field from the limited test results. Thus the spatial interpolation techniques such as Kriging and IDW (inverse distance weighted) have been used for predicting unknown point from existing data. Recently, in order to increase the accuracy of interpolation results, studies that combine the geotechnics and deep learning method have been conducted. In this study, based on the SPT results of about 22,000 holes of ground survey, a comparative study was conducted to predict the depth of the bearing layer using deep learning methods and IDW. The average error among the prediction results of the bearing layer of each analysis model was 3.01 m for IDW, 3.22 m and 2.46 m for fully connected network and PointNet, respectively. The standard deviation was 3.99 for IDW, 3.95 and 3.54 for fully connected network and PointNet. As a result, the point net deep learing algorithm showed improved results compared to IDW and other deep learning method.