• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.365-376
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• 2021

In general, domestic streams and rivers are composed of alluvial rivers consisting of sand and gravel beds. These rivers can cause erosion and riverbed changes due to sudden changes in flow rates, such as floods, torrential rains, and heavy rains. In particular, there are various types of erosion, such as contraction erosion caused by changes in river shape, or local erosion occurring around obstacles such as piers, abutments or embankments. In addition, river changes can occur in various forms, such as static or dynamic periods, due to limitations such as flow rate, velocity, and shear stress. This study focused on the erosions of embankments directly related to human casualties among various river structures, and evaluated limit velocities and critical shear stress in order to identify changes in strength of natural materials by identifying the characteristics of natural hoan materials and resistance to erosions. In particular, the limitations of materials according to the type of materials in the river, characteristics of particles, and size of particles were studied using Soil loss, which is a change in the volume of the revetment material, and it is intended to be used as basic data for river design and restoration.

• International Area Studies Review
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• v.13 no.2
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• pp.393-416
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• 2009

This paper explores the technology resource-based determinants influencing internationalization performance of Korean software-related new ventures. On the ground of the study by Zahra et al.(2003), this paper aims to test empirically in Korea how interaction effects of tangible and intangible technological resources, as firm capability, are related to software new ventures' internationalization performance. The test results shows that intangible technological resource represented by R&D intensity is not significantly related to internationalization performance, but reveals that intangible technological resource represented by strength of technological cooperation network and technological reputation is positively and significantly associated with internationalization performance. Internationalization performance is more significantly and positively associated with the interactions of tangible technological resource and intangible technological resource than those resources respectively. The implication for the findings in the paper is that cutting edge technological capability of software new ventures can be more closely associated with internationalization performance if those resources are fully utilized or leveraged by intangible resources acquired by cooperation with local networks and created through technological reputation of new ventures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.1-12
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• 2019

The purpose of this study is to enhance the seismic performance of exposed column-base plate weak-axis connections for small-sized steel buildings. According to the site inspection for the small-sized building construction, the arbitrary connection details in steel buildings have been applied at the job site, which is considered to be insufficient to guarantee structural safety and stability considering the increased seismic risk in Korea. Therefore, a series of test programs had been done to develop enhanced connection details in order to ensue the adequate seismic stability and safety of small-sized steel buildings. From the test results, It was found that the exposed column-base plate weak-axis connections commonly used in Korea shows very poor seismic behavior due to the "Rocking" phenomena caused by the residual plastic deformation of anchor bolts between anchor plate and concrete. A series of hysteretic tests for finding that solution were conducted to reduce the "Rocking" phenomena of the column-base plate connections, and local buckling of webs in H-column. Finally the enhanced stable seismic behavior was obtained by reinforcing at least 8 anchor bolts with good bonding strength and stiffeners to the webs in H-column.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.1
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• pp.96-109
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• 2019

As the role of universities as a civic university contributing to regional development has been emphasized, industry-academic cooperation projects are increasingly focused on quadruple helix interactions of university, government, business and civic society. Drawing upon focus group interviews, we divided place-based industry-academic cooperation projects into four different types and stages of development, according to two indicators of network participation and network strength. Although the proportion of projects that were in the early stages of development was overwhelmingly high, some universities developed a close cooperative system with the local community to enhance the effectiveness of the industry-academic cooperation projects and to implement them in an advanced stage. These findings suggest that the LINC+ project, which has been criticized for its policy effectiveness, will not only contribute to enhancing policy effectiveness through place-based projects but also enhance the role of universities as the main body of regional innovation.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.353-362
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• 2020

The purpose of this study was to analyze the Gap Between Knowing the importance of and the Actual Implementation of family-centered practices of social workers at local social welfare centers in Gyeonggi-do, and to explore strategies at the institutional level to improve these differences. To this end, a survey was conducted on 232 social workers at 54 community welfare centers in Gyeonggi-do, and the t-test and IPA analysis techniques were used. As a result of the study, first, the importance of family-centered practice of social workers at community welfare centers is highly recognized, but the current performance is low. Second, as a result of verifying the difference in importance-performance regarding family-centered practice, it was found that there were statistically significant differences in all of the 6 sub-factor areas and 18 detailed items of family-centered practice. Third, as a result of IPA analysis of the importance-performance of family-centered practice, at keep up good work(family decision making, comprehensive service), at possible overkill(family focus) was derived, at low priority(family strength, individualization), at concentrate here(cooperation with family) were for each sub-factor. Based on these results, an institutional strategic plan to improve the difference between the importance and performance of family-centered practice was suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.379-384
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• 2021

Despite the numerous graduates being produced in practical music and history, which have not been shorter than 30 years, the employment of students remains an unsolvable task. Most graduates are employed by private institutes as music instructors or got involved in band activities, which are non-regular work and not stable. The rapid development of K-pop along with national strength has changed our lives as well. As a result, the cultural and artistic fields, which were previously recognized only as luxury, have rapidly become popular. In the form of learning, internalized and experiencing, not just watching has a huge impact on improving the quality of our lives. This is reflected in national policies including the operation of cultural arts, education programs in elementary, middle, and high schools, and art programs designed to improve the welfare of residents at local community centers. It is time to expand its job-horizon to the relevant fields, and thus focus on promoting programs related to obtaining certificates to help our students find jobs. In addition, the government should create a course for music teacher certification in the field of practical music that differs from the current music teacher certification of secondary schools. It is very urgent to establish the teaching course in four-year universities or graduate schools of practical music education.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.419-426
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• 2020

Understanding the pore structure including pore shape and connectivity in unconventional reservoirs is essential to increase the recovery rate of unconventional energy resources such as shale gas and oil. In this study, we found analysis condition to probe the nanoscale pore structure in shale reservoirs using Focused Ion Beam (FIB) and Ion Milling System (IMS). A-068 core samples from Liard Basin are used to probe the pore structure in shale reservoirs. The pore structure is analyzed with different pretreatment methods and analysis condition because each sample has different characteristics. The results show that surface milling by FIB is effective to obtain pore images of several micrometers local area while milling a large-area by IMS is efficient to observe various pore structure in a short time. Especially, it was confirmed that the pore structure of rocks with high content of carbonate minerals and high strength can be observed with milling by IMS. In this study, the analysis condition and process for observing the pore structure in the shale reservoirs is established. Further studies are needed to perform for probing the effect of pore size and shape on the enhancement of shale gas recovery.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.3
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• pp.3-12
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• 2005

This paper introduces a 3D perceptual model based on JND(Just Noticeable Difference) and proposes a video watermarking scheme which is perceptual approach of adaptive embedding in 3D-DCT domain. Videos are composed of consecutive frames with many similar adjacent frames. If a watermark is embedded in the period of similar frames with little motion, it can be easily noticed by human eyes. Therefore, for the transparency the watermark should be embedded into some places where motions exist and for the robustness its magnitude needs to be adjusted properly. For the transparency and the robustness, watermark based on 3D perceptual model is utilized. That is. the sensitivities from the 3D-DCT quantization are derived based on 3D perceptual model, and the sensitivities of the regions having more local motion than global motion are adjusted. Then the watermark is embedded into visually significant coefficients in proportion to the strength of motion in 3D-DCT domain. Experimental results show that the proposed scheme improves the robustness to MPEG compression and temporal attacks by about $3{\sim}9\%$, compared to the existing 3D-DCT based method. In terms of PSNR, the proposed method is similar to the existing method, but JND guarantees the transparency of watermark.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.113-119
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• 2022

In order to improve the mechanical reliability of next-generation electronic devices including flexible, wearable devices, a high level of mechanical reliability is required at various flexible joints. Organic adhesive materials such as epoxy for bonding existing polymer substrates inevitably have an increase in the thickness of the joint and involve problems of thermodynamic damage due to repeated deformation and high temperature hardening. Therefore, it is required to develop a low-temperature bonding process to minimize the thickness of the joint and prevent thermal damage for flexible bonding. This study developed flexible laser transmission welding (f-LTW) that allows bonding of flexible substrates with flexibility, robustness, and low thermal damage. Carbon nanotube (CNT) is thin-film coated on a flexible substrate to reduce the thickness of the joint, and a local melt bonding process on the surface of a polymer substrate by heating a CNT dispersion beam laser has been developed. The laser process conditions were constructed to minimize the thermal damage of the substrate and the mechanism of forming a CNT junction with the polymer substrate. In addition, lap shear adhesion test, peel test, and repeated bending experiment were conducted to evaluate the strength and flexibility of the flexible bonding joint.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.265-288
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• 2020

Public sports facilities, which have increased in number due to continued government attention and investment, are used by a large number of residents in the province. However, the safety management in some facilities is limited due to being carried out with reference to safety management standard manuals as a mere formality. The purpose of this study was to analyze the current safety management status of public sports facilities in Gangwon and to seek out a policy direction that can be used safely by provincial residents. To this end. the study made a comprehensive review of central government and Gangwon government policy trends in sports facility safety management in Gangwon along with actual cases, from which it made the following suggestions for policy directions. First, it proposed the designation and operation of specialized institutions using locally established development and municipal companeie,. universities and cooperatives. and the training and fostering of safety managers for sports facilities. Secod, it proposed the establishment of a foundation to promote a sport facility safety culture such as designation of and commendation for excellent facility safety management on the provincial level. holding case presentations on safety and responsiveness. sports safety experience plazas, sports safety classes, and cartoons for public relations. Third, it proposed setting the foundation for a safety management system that takes into account the greater quantity of leisure sports facilities compared to other cities and provinces. Fourth, it proposed the establishment of an institutional basis to establish support ordinance for sports facility safety management that meets the local conditions in Gangwon. Fifth, it proposed safety management measures for sports facilities at the central government level in parallel with a basic plan for sports facility safety management tailored to Gangwon that matches the conditions on the ground in the region.