• KSCE Journal of Civil and Environmental Engineering Research
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• 제26권6A호
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• pp.977-988
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• 2006

The goal of this study is to develop a realistic methodology for determination of the Life-Cycle Cost (LCC)-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges. The proposed methodology is based on the concept of minimum LCC which is expressed as the sum of present value of seismic retrofit costs, expected maintenance costs, and expected economic losses with the constraints such as design requirements and acceptable risk of death. The proposed methodology is applied to the LCC-effective optimal seismic retrofit and maintenance strategy of a steel bridge considered as a example bridge in the accompanying study, and various conditions such as corrosion environments and Average Daily Traffic Volumes (ADTVs) are considered to investigate the effects on total expected LCC. In addition, to verify the validity of the developed methodology, the results are compared with the existing methodology. From the numerical investigation, it may be positively expected that the proposed methodology can be effectively utilized as a practical tool for the decision-making of LCC-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges.

• 한국노년학
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• 제30권4호
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• pp.1263-1280
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• 2010

The present study describes the acculturation meaning of 12 Chinese-Chosun residential care attendants(RCAs) who are currently working in long-term care settings for Korean older adults. Using a qualitative research method, the findings show that the acculturation process of Chinese-Chosun RCAs consists of three stages: entrance, conflict, and adaptation. In the initial stage, the assets of the social and cultural networks among their friends and relatives, who already settled down or employed as RCAs, provided more opportunities for being employed as a RCA. However, most Chinese-Chosun RCAs experienced a number of conflicts while they adapted to mainstream society and perform caregiving tasks. They perceived discrimination, heavy workload, prejudice, and homesick. Nevertheless, they appeared to adapt effectively to Korean society and working environments because they were aware of the various benefits of working as a RCA such as higher wage and more job openings compared to other jobs, a rapport with the patients and patients' families, flexible work hours, and pride as a caregiver. This type of qualitative groundwork will be an important precursor to the design, implementation, and evaluation of acculturation research for minority immigrant workers in the Korean social welfare system.

• Asia Marketing Journal
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• 제10권2호
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• pp.71-98
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• 2008

Considerably many numbers of studies on country-of-origin(hereafter COO) effects have been presented in international business and marketing areas. Recent studies have been included the effects of COO of manufacture, parts, and design, as well as the effects of brand origin, reflected by the accelerating convergent manufacture circumstances and increasingly competitive environments. Moderating constructs such as knowledge of product category and involvement as individual variables, have been also introduced and researched in various angles. In addition, how the effects of COO occur as processes is also argued in previous studies. This research has attempted to explain business corporation's strategic decisions on choosing a domain of its product manufacturing for several critical reasons, for cost reduction or better image. We displayed two constructs of brand and manufacture in a positive and negative country image group to reconfirm the existence of the effects of COO. Additionally, the effects of respondents' regulatory fit between their motivational focus and the contents of product messages, have been declared. Furthermore the respondents' motivational focus moderates the main effect of COO on product evaluations in a positive 'made-in' combination, while, surprisingly, it does not statistically moderate in a negative, except attitude. Based on the results, implications and suggestions on how to plan and execute more effective marketing strategies regarding COO dimensions, especially COO of manufacture, are separately presented for each situations when it has already been determined and when it is to be.

• Journal of the Korean Applied Science and Technology
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• 제41권1호
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• pp.96-106
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• 2024

This study aimed to examine the effects of non-face-to-face sleep program combined with aroma necklace on quality of sleep, daytime sleepiness, depression, and stress in insomnia with college students. A nonequivalent control group pre-post test design was used. The experimental group(n=21) underwent non-face-to-face sleep program combined with aroma-necklace while the control group(n=21) received a sleep booklet. Sleep quality, daytime sleepiness, depression, and stress were measured to identify the effectiveness of the program. Data were analyzed using descriptive statistics, Fisher's exact test, χ²-test, and independent t-test with the SPSS 24.0 program. In the homogeneity test of the general characteristics and study outcome variables there were no significant differences between the two groups. Significant group differences were found in sleep quality (t=-5.87, p<.001), daytime sleepiness(t=-4.28, p<.001), and depression(t=-4.40, p<.001). No differences were found in the stress. Non-face-to-face sleep improvement program combined with an aroma-necklace was effective in improving insomnia in college students. Nurses can contribute to improving sleep and depression by applying this program to college students experienced insomnia living in various environments.

• Journal of the Korean Geotechnical Society
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• 제40권1호
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• pp.5-14
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• 2024

PHC piles demonstrate superior resistance to compression and bending moments, and their factory-based production enhances quality assurance and management processes. Despite these advantages that have resulted in widespread use in civil engineering and construction projects, the design process frequently relies on empirical formulas or N-values to estimate the soil-pile friction, which is crucial for bearing capacity, and this reliance underscores a significant lack of experimental validation. In addition, environmental factors, e.g., the pH levels in groundwater and the effects of seawater, are commonly not considered. Thus, this study investigates the influence of vibrating machine foundations on PHC pile models in consideration of the effects of varying pH conditions. Concrete model piles were subjected to a one-month conditioning period in different pH environments (acidic, neutral, and alkaline) and under the influence of seawater. Subsequent repeated direct shear tests were performed on the pile-soil interface, and the disturbed state concept was employed to derive parameters that effectively quantify the dynamic behavior of this interface. The results revealed a descending order of shear stress in neutral, acidic, and alkaline conditions, with the pH-influenced samples exhibiting a more pronounced reduction in shear stress than those affected by seawater.

• The Journal of the Convergence on Culture Technology
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• 제10권1호
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• pp.297-305
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• 2024

As society changes rapidly, the role and status of general education has produced many changes, and accordingly, it is forming a close relationship with various social and cultural environments around the school. Especially, the direction in which general education should proceed and the development of regional-linked general education models have been actively studied at a time when the relationship between local regions and universities is getting strong. In this study, we have provided significant policy implications related to the development and application of future university-local cooperation models by developing a subject of community service activities based learning (CSAL) to get closer to community service and by analyzing actual educational cases and applying them to real community service organizations. In addition, we closely collaborated with local volunteer organizations operated by this local government system to connect with local community service, and through this, we reviewed actual cooperative classes with a local university and local volunteer organizations for the class curriculum, and developed a model to activate the university-local educational ecosystem.

• Journal of the Society of Disaster Information
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• 제20권1호
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• pp.206-212
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• 2024

Purpose: This study conducted research on the sharing of information to enhance the survival rate of emergency patients by swiftly transferring them to appropriate hospitals through sharing the patients' conditions, treatment histories, and transportation information with the Maritime Police Agency and relevant agencies when emergencies occur in the marine environment. Methods: In this study, emergency patient information classified in a smartphone app was received, stored, and transmitted using the LoRa communication method by electronic triage tags, and the transmitted emergency patient information was implemented to be collected in real-time through a hybrid triage system along with LoRa receivers. Results: Through the hybrid triage system, it was possible to receive emergency patient information according to the distance or confirm delayed reception. It was observed that most data were received when the distance was short, while data reception was unsuccessful in relatively longer distances. Conclusion: It was confirmed that in mass disaster environments where internet communication is impossible, rapid and accurate understanding of casualty information at disaster sites and appropriate disaster responses can be achieved using self-networking methods such as LoRa communication. However, limitations inherent in communication methods were also recognized. Further research on various communication methods is required to collect emergency patient information and transfer them to appropriate hospitals in situations where internet communication is unavailable.

• Journal of the Korea institute for structural maintenance and inspection
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• 제28권2호
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• pp.35-42
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• 2024

This study evaluated the buildability and mechanical properties of 3DP concrete printed in air and underwater environments. Buildability was evaluated by green strength test on fresh concrete and height and deflection immediately and 1 hour after printing. The green compressive strength of the concrete was 5.0 kPa after 30 minutes and 7.9 kPa after 3 hours, an increase of 1.6 times the initial strength. The total height of the laminated parts met the design height regardless of the printing environment. The amount of deflection in air and under water 1 hour after printing was 1 mm and 0.2 mm, respectively, indicating a small amount of deflection under water. The apparent density of the sample appeared in the order of A-M > A-P > UW-P. This is believed to be because a large amount of air is mixed into the concrete during the printing process, and water infiltrates during the underwater printing process. The compressive strength ratio of UW-P/A-P was 0.86 at 1 day, but the compressive strength of the underwater printed concrete was high from 7 days.

• Tunnel and Underground Space
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• 제34권3호
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• pp.231-247
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• 2024

In the field of high-level radioactive waste disposal targeting deep rock environments, hydraulic characteristic information serves as the most important key factor in selecting relevant disposal sites, detailed design of disposal facilities, derivation of optimal construction plans, and safety evaluation during operation. Since various rock types are mixed and distributed in a small area in Korea, it is important to conduct preliminary work to analyze the hydrogeological characteristics of rock aquifers for various rock types and compile the resulting data into a database. In this paper, we obtained hydraulic conductivity data, which is the most representative field hydraulic characteristic of a high-depth volcanic bedrock aquifer, and also analyzed and evaluated the field data. To acquire field data, we used a high-performance hydraulic testing system developed in-house and applied standardized test methods and investigation procedures. In the process of hydraulic characteristic data analysis, hydraulic conductivity values were obtained for each depth, and the pattern of groundwater flow through permeable rock joints located in the test section was also evaluated. It is expected that the series of data acquisition methods, procedures, and analysis results proposed in this report can be used to build a database of hydraulic characteristics data for high-depth rock aquifers in Korea. In addition, it is expected that it will play a role in improving technical know-how to be applied to research on hydraulic characteristic according to various bedrock types in the future.

• Journal of the Korea Society for Simulation
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• 제33권2호
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• pp.1-11
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• 2024

A cyber-physical system is a technology that connects the physical systems of a manufacturing environment with a cyber space to enable simulation. One of the major challenges in this technology is the seamless communication between these two environments. In complex manufacturing processes, it is crucial to adapt to various protocols of manufacturing equipment and ensure the transmission and reception of a large volume of data without delays or errors. In this study, we propose a method for constructing agent models for real-time simulation-capable cyberphysical systems. To achieve this, we design data collection units as independent agent models and effectively integrate them with existing simulation tools to develop the overall system architecture. To validate the proposed structure and ensure reliability, we conducted empirical testing by integrating various equipment from a real-world smart microfactory system to assess the data collection capabilities. The experiments involved testing data delay and data gaps related to data collection cycles. As a result, the proposed approach demonstrates flexibility by enabling the application of various internal data collection methods and accommodating different data formats and communication protocols for various equipment with relatively low communication delays. Consequently, it is expected that this approach will promote innovation in the manufacturing industry, enhance production line efficiency, and contribute to cost savings in maintenance.