• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.585-593
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• 2021

Background and objective: Illegal open-air incineration, which is criticized as a leading source of air pollutants among agricultural activities, currently requires constant effort and attention. Countries around the world have been undertaking studies on the emission of heavy metal substances in fine dust discharged during the incineration process. A precise analytical method is required to examine the harmful effects of particulate pollutants on the human body. Methods: In order to simulate open-air incineration, the infrastructure needed for incineration tests complying with the United States Environmental Protection Agency (EPA) Method 5G was built, and a large-area analysis was conducted on particulate pollutants through automated scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS). For the test specimen, high-density polyethylene (HDPE) waste collected by the DangJin Office located in Choongcheongnam-do was used. To increase the identifiability of the analyzed particles, the incineration experiment was conducted in an incinerator three times after dividing the film waste into 200 g specimens. Results: Among the metal particulate matters detected in the HDPE waste incineration test, transition metals included C (20.8-37.1 wt%) and O (33.7-37.9 wt%). As for other chemical matters, the analysis showed that metal particulate matters such as metalloids, alkali metals, alkaline earth metals, and transition metals reacted to C and C-O. Si, a representative metalloid, was detected at 14.8-20.8 wt%, showing the highest weight ratio except for C and O. Conclusion: In this study, the detection of metal chemicals in incinerated particulate matters was effectively confirmed through SEM-EDS. The results of this study verified that HDPE waste adsorbs metal chemicals originating from soil due to its own properties and deterioration, and that when incinerated, it emits particulate matters containing transition metals and other metals that contribute to the excessive production and reduction of reactive oxygen species.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.3950-3969
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• 2021

Radio Frequency (RF)-based indoor localization technologies play significant roles in various Internet of Things (IoT) services (e.g., location-based service). Most such technologies require that all the devices comply with a specified technology (e.g., WiFi, ZigBee, and Bluetooth). However, this requirement limits its application scenarios in today's IoT context where multiple devices complied with different standards coexist in a shared environment. To bridge the gap, in this paper, we propose a cross-technology localization approach, which is able to localize target nodes using a different type of devices. Specifically, the proposed framework reuses the existing WiFi infrastructure without introducing additional cost to localize Non-WiFi device (i.e., ZigBee). The key idea is to leverage the interference between devices that share the same operating frequency (e.g., 2.4GHz). Such interference exhibits unique patterns that depend on the target device's location, thus it can be leveraged for cross-technology localization. The proposed framework uses Principal Components Analysis (PCA) to extract salient features of the received WiFi signals, and leverages Dynamic Time Warping (DTW), Gradient Boosting Regression Tree (GBRT) to improve the robustness of our system. We conduct experiments in real scenario and investigate the impact of different factors. Experimental results show that the average localization accuracy of our prototype can reach 1.54m, which demonstrates a promising direction of building cross-technology technologies to fulfill the needs of modern IoT context.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.396-416
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• 2021

Objectives: This study was conducted to analyze the trends of government R&D (R&D) projects related to laboratory safety over the past 20 years. Methods: We collected publications from various databases(DBs) with words such as laboratory(ies), lab(s), researcher(s), laboratory worker(s), safety, environment, hazard(s), risk(s), and so on. Selected publications were analyzed by the research funds and the number of projects according to the investment subject and research characteristics. Results: About 93% of the total R&D budget went to government policy projects, not scientific research. Second, from the perspective of 'safety management activities', most of the research is related to management and inspection at the organizational level. Issues that need to be discussed at the national level like policy governance are not included. Third, focusing on the 'safety management cycle', there were few studies related to 'prediction' or 'post-response'. Fourth, when an analysis framework combining the perspectives of 'safety management activities' and 'safety management cycle' is applied, most of the budget is spent on infrastructure such as digital management systems, whereas basic knowledge for prevention and production of evidence was very few. Conclusions: In order to prevent policy planning without policy evaluation, implementation without strategy, and evaluation without evidence, it is necessary to expand investment in empirical research on risks, research on the effectiveness of current application methods, and research on theory development. The government budget for laboratory safety-related projects should be managed separately from the R&D budget for scientific research. Although less than 5% of the budget allocated to scientific research is the total budget, an optical illusion occurs because both the project budget and the scientific research budget are counted as R&D budgets.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.60-69
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• 2022

To keep pace with Industry 4.0, it is imperative for companies to redesign their working environments by adopting robotic automation systems. Automation lines are facilitating the latest cutting-edge technologies, such as 3D vision and industrial robots, to outdo competitors by reducing costs. Considering the nature of the manufacturing industry, a time-saving workflow and smooth linkwork between processes is vital. At Dellics, without any additional new installation in the automation lines, only a few improvements to the working process could raise productivity. Three requirements are the development of gripping technology by utilizing a 3D vision system for the recognition of the material shape and location, research on lighting projectors to target long distances and high illumination, and testing of algorithms/software to improve measurement accuracy and identify products. With some of the functional requisites mentioned above, improved robotic automation systems should provide an improved working environment to maximize overall production efficiency. In this article, the ways in which such a system can become the groundwork for establishing an unmanned working infrastructure are discussed.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.47-55
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• 2022

The objective of this study was to analyze the effect of the duration and time distribution of probability rainfall on farmland inundation for the paddy fields in the drainage improvement project site. In this study, eight drainage improvement project sites were selected for inundation modeling. Hourly rainfall data were collected, and 20- and 30-year frequency probability rainfalls were estimated for 14 different durations. Probability rainfalls were distributed using Intensity-Duration-Frequency (IDF) and Huff time distribution methods. Design floods were calculated for 48 hr and critical duration, and IDF time distribution and Huff time distribution were used for 48 hr duration and critical duration, respectively. Inundation modeling was carried out for each study district using 48 hr and critical duration rainfalls. The result showed that six of the eight districts had a larger flood discharge using the method of applying critical duration and Huff distribution. The results of inundation depth analysis showed similar trends to those of design flood calculations. However, the inundation durations showed different tendencies from the inundation depth. The IDF time distribution is a distribution in which most of the rainfall is concentrated at the beginning of rainfall, and the theoretical background is unclear. It is considered desirable to apply critical duration and Huff time distribution to agricultural production infrastructure design standards in consideration of uniformity with other design standards such as flood calculation standard guidelines.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.376-385
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• 2022

The embedded demountable shear connector was developed in preparation for replacement works due to deterioration and damage to the bridge panel of the PSC girder bridge which is a road infrastructure directly related to the safety and convenience of the people. The demountable shear connector minimizes crushing works in the demolition process of the panel, and it is easy to re-construct the shear connector for replacement work. The economic feasibility of the PSC girder bridge using the embedded demountable shear connector compared to the existing construction method was analyzed from the perspective of road users (people) by calculating and comparing the cost of road users caused by traffic blocking during each construction method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.887-892
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• 2022

Due to various reasons (normally financial constraints in developing countries), it becomes common to change of the business model from state-run projects to Private Investment Projects (Public Private Partnership) in the global railway businesses. However, due to the nature of railroads compared with other types of infrastructure such as roads and others, railway business require considerable construction cost and O&M cost through the business development, construction, and operation and management stages. Therefore, private investment railway projects, especially in developing countries, can be problematic in terms of the potential for uncertainty when return on investment cannot be guaranteed. In order to strengthen the competitiveness of domestic companies when entering overseas railroad PPP projects, this study proposes PPP-related risks and their countermeasures by reviewing global railroad trends and identifying Korea's weakness in managing international railroad projects.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.29-43
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• 2022

Various underground facilities are being constructed to improve the urban environment. Therefore, it is more necessary than ever to reasonably evaluate the seismic response of underground utility tunnels, playing a significant part in urban infrastructure. In this study, the major features and differences of two types of existing pseudo-static analysis methods are reviewed. Each method uses a simplified 2D frame model to represent the seismic behavior of underground structures. Applying each method to a one-barrel rectangular utility tunnel in Korea, the suitability in predicting seismic responses, especially the racking deformation of the tunnel, is examined. In addition, several precautions and suggestions are provided in this study against the inattentive application of the methods to seismic evaluation of underground structures.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.275-280
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• 2023

Currently, the cumulative number of confirmed cases from the coronavirus in Korea is 30.17 million, and the cumulative number of deaths also reaches 33,444 (as of January 31, 2023). Therefore, this study aims to conduct an empirical analysis on the establishment of quarantine systems in major domestic cities as it is necessary to analyze the influencing factors of COVID-19 and discuss policy directions necessary to establish an effective quarantine system in the future. Among them, 16 cities in Korea with a relatively weak quarantine infrastructure were compared with the interrelationship between "number of upper-level hospitals", "number of urban populations", "number of infected", and "number of deaths", and ultimately the results of quarantine for each local government. In conclusion, the average population of 16 cities is 0.792 million, and the average number of infected people is 0.458 million, and the average cumulative infection rate is 57.8%. Seven cities exceed the average cumulative infection rate: Suwon (61.6%), Yongin (59.1%), Seongnam (61.8%), Hwaseong (65.6%), Anyang (60.7%), Cheonan (62.9%), and Jeonju (62.9%). In addition, despite the establishment of excellent treatment facilities in the city (ave=0.0129), the ratio of "accumulated deaths" (ave=0.11%) was high in Changwon (0.12%/0.0193), Ansan (0.12%/0.0138), Cheongju (0.11%/0.0174), and the ratio of "accumulative deaths" was low (0.09%) despite the construction of relatively poor treatment facilities. Through the results of this study, we expect a paradigm shift in the infectious disease management system in major cities in Korea after post-COVID-19.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1207-1212
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• 2022

Realistic media, the next-generation media technology in the era of the 4th industrial revolution, is becoming an issue as a technology to experience through an environment that optimizes user experience, especially! It is rapidly developing into the health and healthcare convergence and complex fields. Realistic media technologies and services are being adopted to solve the problems of the increase in chronic diseases due to the increase in the elderly population and the lack of infrastructure and professional manpower in the fields of cognitive training and rehabilitation. Therefore, in this study, a cognitive training system was designed and implemented for the purpose of improving cognitive ability and daily life activity in subjects with mild cognitive impairment (MCI) who require cognitive rehabilitation. In the future, an integrated service platform with interactive communication and immediate feedback as an intelligent cognitive rehabilitation integrated platform based on AI and BigData is left as a research project.