• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.855-865
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• 2018

Sound event detection is one of the research areas to model human auditory cognitive characteristics by recognizing events in an environment with multiple acoustic events and determining the onset and offset time for each event. DCASE, a research group on acoustic scene classification and sound event detection, is proceeding challenges to encourage participation of researchers and to activate sound event detection research. However, the size of the dataset provided by the DCASE Challenge is relatively small compared to ImageNet, which is a representative dataset for visual object recognition, and there are not many open sources for the acoustic dataset. In this study, the sound events that can occur in indoor and outdoor are collected on a larger scale and annotated for dataset construction. Furthermore, to improve the performance of the sound event detection task, we developed a dual CNN structured sound event detection system by adding a supplementary neural network to a convolutional neural network to determine the presence of sound events. Finally, we conducted a comparative experiment with both baseline systems of the DCASE 2016 and 2017.

• Journal of Internet Computing and Services
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• v.20 no.2
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• pp.39-49
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• 2019

Advances in IoT data analysis technology have made it easier to analyze situation and provide interactive services based on the context. Most of digital signage application have been used to provide information uni-directionally, but in the future it will evolve to provide personalized content according to the individual user situation and responses. However, it is not easy to modify or apply the existing interactive digital signage platforms due to their hardware dependency. The proposed platform is modularized by dividing main functions into two, the cloud and the edge, so that advertisement resources can be easily generated and registered. Thus, interactive advertisement can be rendered in a timely manner based on sensor analysis results. At the edge, personal data can be processed to minimize privacy issues, and real-time IoT sensor data can be analyzed for quick response to the signage player. The cloud is easier to access and manage by multiple users than edge. Therefore, the signage content generation module improves accessibility and flexibility by handling advertisement contents in the cloud so that multiple users can work together on the cloud platform. The proposed platform was developed and simulated in two aspects. First is the provider who provides the signage service, and second is the viewer who uses the content of the signage. Simulation results show that the proposed platform enables providers to quickly construct interactive signage contents and responses appropriately to the context changes in real-time.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.64-77
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• 2021

Objective: Biological monitoring of trace elements in human blood samples has become an important indicator of the health environment. The purpose of this study was to detect and evaluate multiple metal items in blood samples based on ICP-MS, to perform comparative evaluation with the existing analysis method, and to develop and verify a new method. Methods: 100 μL of whole blood from 80 healthy subjects was used to analyze ten metals (Sb, tAs, Cd, Pb, Mn, Hg, Mo, Ni, Se, Tl) using ICP-MS. Verification of the analysis method included calculation of linearity, accuracy, precision and detection limits. In addition, a comparative test with the conventional graphite furnace atomic absorption spectroscopy (GF-AAS) method was performed. In the case of Pb, Cd, and Hg in whole blood, cross-analysis between Pb, Cd, and Hg analysis methods was performed to confirm the difference between the existing method and the new method (ICP-MS). Results: The coefficient of determination (R2) was 0.999 or higher in seven items and 0.995 or higher in three items. The Pb result showed that Pearson's correlation coefficient was very high at 0.983, and the intraclass correlation coefficient was 0.966. The Cd result showed that Pearson's correlation coefficient was 0.917 between the existing method and the new analysis concentration value. Its intraclass correlation coefficient was 0.960, and there was no significant difference between the two groups. Hg had a low correlation at 0.687, and the intraclass correlation coefficient was 0.761, which was lower than that of Pb and Cd. The intra-day and inter-day accuracy of Pd and Cd were satisfactory, but Hg did not meet the criteria for both accuracy and precision when compared with the conventional analysis method. Conclusion: This study can be meaningful in that it proposes a more efficient and feasible analysis method by verifying a blood heavy metal concentration experiment using multiple simultaneous analyses. All samples were processed and analyzed using the new ICP-MS. It was confirmed that the agreement between the two methods was very high, with the agreement between the current and new methods being 0.769 to 0.998. This study proposes an efficient simultaneous methodology capable of analyzing multiple elements with small samples. In the future, studies of various applications and the reliability of ICP-MS analysis methods are required, and research on the verification of accurate, precise, and continuous analysis methods is required.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.88-96
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• 2021

There have been many efforts to identify and eliminate the direct causes of the construction accident, but many accidents are still occurring in the construction industry. The main reason for the construction accident is not because of ignorance of the causes, but because of safety insensitivity. This paper analyzes why construction workers feel safety insensitivity and how safety insensitivity varies depending on their age and work experience. A survey of 103 construction workers confirmed that systematic safety education is the most important factor in minimizing safety insensitivity of construction workers. On the other hand, economic reasons such as cost reduction were identified as the most tempting factor to increase safety insensitivity. In addition, the survey results showed that those in their 40s and 50s, the largest proportion of construction workers, have a significantly higher level of safety insensitivity than those in their 20s and 60s. These findings are expected to be valuable source that can be used to prevent construction safety accidents.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.85-91
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• 2021

Aggregate waste separator with rotating separating net was designed for applying classification process of construction waste. In order to evaluate the performance of the aggregate waste separator, according to the type of waste, standardized waste samples are prepared using acrylic. The appropriate operating point was evaluated by the classification efficiency and misclassification rate of recycled aggregate according to the control frequency of the blower operating and inlet position of the separating net. The classification efficiency at the operating point of the aggregate waste separator was evaluated through flow analysis assuming recycled aggregate and waste sample as particles. As a result of the performance test, when the distance. between the conveyor belt and the inlet was 0.2m, the classification efficiency was 95%, but the misclassification rate of recycled aggregate was 2% or more, which satisfies the classification efficiency and the misclassification rate of less than 2%. The operating point was shown at a control frequency of 58Hz at a suction distance of 0.254m. As a resu lt of flow analysis, there was no misclassification of recycled aggregate. In order to redu ce constru ction waste in the existing recycled aggregate production process, adsorption system using a rotating separating net that can be operated as an installation type was built.

• Journal of Korean Society of Rural Planning
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• v.27 no.1
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• pp.57-70
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• 2021

The degree of benefits of living services related to the quality of life can solve the depopulation problem, and it is necessary to be able to quantitatively analyze problems related to the quality of life in rural areas in order to cope with the rural depopulation. The purpose of this study was to develop the assessment model of a village-level rural living service that reflects the regional characteristics of rural villages to evaluate the level of rural living services for response rural depopulation. Based on the review of previous related studies, the evaluation index was composed of seven sectors of education, health, welfare, culture, environment, safety, and convenience, and the assessment model of a rural living service was established. This model was evaluated through a sample survey of 90 villages in Nonsan-si, Seongju-gun, and Pyeongchang-gun. As a result of the rural life services evaluation by Si and Gun, Seongju-gun, which is affected by nearby large cities, has the largest variation by village level and is assessed at a lower level overall than other Si and Gun. As a result of the rural life services evaluation by 7 sectors, in the case of health and welfare, low scores were shown in the assessment model, but the level of residents' satisfaction was mid-level. In particular, in the case of Seongju-gun, there were significant differences in the assessment model and the survey results of the level of residents' satisfaction in the health and welfare sectors due to the influence of nearby large cities. As a result of analyzing the number of villages corresponding to the top 30% and the bottom 30% of the evaluation results for each sector, it was analyzed that the villages with the highest evaluation results in Pyeongchang-gun in both the assessment model and the level of residents' satisfaction. It implies that quantitative analysis of data based index and accessibility as well as level satisfaction of residents are necessary.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.7-13
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• 2021

Various research has been done on fires and explosions at gas stations at home and abroad. However, only studies of off-site damage in the event of fire at the gas station were conducted, and research on fire at the auxiliary facilities in the gas station was insufficient. The gas station is a place where anyone can easily access dangerous goods. As the risk of fire increases due to the recent increase of auxiliary facilities such as convenience stores and car repair shops in gas stations, it is important to detect the effects of fire on the main oil refinery in case of fire and to verify the validity of existing regulations. In this thesis, we conducted a study to find out the effect of radiation heat on the separation between fixed and fixed oil reactors in the event of fire at an auxiliary facility. Simulation was modelled using FDS 5.5.3 Version, and the size of the fire source was configured with 13 fire assessment devices and the heat emission rate per unit area was entered. Simulation shows that the separation distance of 2 m does not secure the safety of the gas pump in the event of fire at the auxiliary facilities, and radiation heat does not damage at the separation distance of at least 4 m. Accordingly, facilities that can block radiant heat in the event of fire at auxiliary facilities, and measures to limit the use of auxiliary facilities or to re-impose the separation between buildings and fixtures will be needed.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.202-210
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• 2022

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.

• Korean small business review
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• v.43 no.1
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• pp.85-105
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• 2021

This study verified how R&D investment affects the management performance of SMEs, whether technology innovation mediates this relationship, and whether marketing competency moderates the relationship between technology innovation and management performance. A longitudinal analysis was conducted using data from the corporate panel survey performed by Daegu Technopark every year since 2013. Data from 349 companies in the Daegu-Gyeongbuk region were mainly used, and the size of 30 to 50 employees in the manufacturing industry was a major analysis target company. The results are as below. First, The results showed that R&D investment had a positive effect on management as well as technology innovation, but technology innovation did not affect management performance. Also, technological innovation did not mediate the relationship between R&D investment and management performance. This shows that in the case of small SMEs, even if technological innovation occurs through R&D investment, the technological innovation does not lead to management performance. Also, the relationship between technological innovation and management performance was not changed by marketing capabilities. This shows that technological innovation in small SMEs is not easy to lead to business performance.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.375-388
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• 2021

This study aims to contribute to the understanding of consumer behavior during the COVID-19 by comparing blog reviews of an over-the-top (OTT) online video service from before and during the pandemic. We anticipate that the COVID-19 outbreak prompts the use of the OTT service as part of an emotion-focused coping strategy derived from the loss of personal control and the subsequent avoidance motivation. We also posit that a strong yearning for life before COVID-19 will increase interest in the content that fulfills a need for nostalgia. Our analysis of Netflix reviews provides empirical evidence of the effects of an emotion-focused coping strategy and nostalgia on OTT service usage. First, the titles of the reviews posted during COVID-19 indicate that consumers were less likely to mention OTT services other than Netflix, more interested in domestic content, and used OTT services as an avoidance-denial strategy. Second, the blog content demonstrates that while pre-COVID reviews tend to focus on the practical benefits of OTT services, those posted during the pandemic focus on mood, emotions, and dialogue. In addition, interest in comedy and romance genres increased during COVID-19. Third, we identified a greater preference for realistic or everyday content that depicted the pre-pandemic era. This is the first empirical study to investigate the effects of COVID-19 on video streaming usage in Korea. In addition, this research contributes to the field of marketing by expanding our understanding of online video service users during COVID-19 and identifies practical implications for OTT services in the midst of a pandemic.