• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.24-34
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• 2021

Estimation of the presence of people in real time is extremely useful for businesses in providing better services. Many companies and researchers have attempted various researches in order to count the number of floating population in specific space. Recently, as part of smart cities and digital twins, commercialization of measuring floating populations using Wi-Fi signals has become active in the public and private sectors. This paper explains the floating population measuring system from the perspective of general consumers(non-experts) who uses current population data. Specifically, it presents a method of estimating the floating population based on MAC-address values collected from smartphones. By distinguishing Real MAC-address and Random MAC-address values, we compare the estimated number of smartphone devices and the actual number of people caught on CCTV screens to evaluate the accuracy of the proposed method. And it appeared to have a similar correlation between the two datas. As a result, we present a method of estimating the floating population based on analyzing Wi-Fi Probe Requests

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.214-217
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• 2022

In the maritime digital forensic part, it is very important and difficult process that analysis of data and information with vessel navigation system's binary log data for situation awareness of maritime accident. In recent years, analysis of vessel's navigation system's trajectory information is an essential element of maritime accident investigation. So, we made an experiment about corruption with various memory device in navigation system. The analysis of corruption test in seawater give us important information about the valid pulling time of sunken ship for acquirement useful trajectory information.

• Asia Marketing Journal
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• v.7 no.1
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• pp.67-89
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• 2005

In recent decades, product variety has increased dramatically in most industries. Rapidly evolving technologies, global competition, and sophisticated customers have contributed to an increase in product variety in many industries. In this paper, I study the impact of product variety on several businesses in the supply chain through literature review. By study of literature. this paper presents the benefits and drawbacks of increasing product variety on functions performed in several departments, such as engineering, manufacturing, purchasing, logistics and marketing. It provides a brief overview of the various techniques like modularity, component sharing, and platform-based development, which are helpful in reducing the costs, when designing for variety. It also provides a brief overview of order processing, purchased component/part variety, which are helpful in reducing the purchasing costs, and customer satisfaction, market advantage, market share, competitive advantage and demand forecast, which are useful in impact of product variety on marketing. Future research directions are discussed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.98-99
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• 2023

In the maritime digital forensic part, it is very important and difficult process that analysis of data and information with vessel navigation system's binary log data for situation awareness of maritime accident. In recent years, analysis of vessel's navigation system's trajectory information is an essential element of maritime accident investigation. So, we made an experiment about corruption with various memory device in navigation system. The analysis of corruption test in seawater give us important information about the valid pulling time of sunken ship for acquirement useful trajectory information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.139-141
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• 2021

In the maritime digital forensic part, it is very important and difficult process that analysis of data and information with vessel navigation system's binary log data for situation awareness of maritime accident. In recent years, anaysis of vessel's navigation system's trajectory information is an essential element of maritime accident investigation for vessel digital forensic process. So, we analysis of maritime navigation systems of vessel and feature of device and environments. In the future, we will research on information of ship's trajectory and movement for useful forensic service.

• Journal of Naturopathy
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• v.7 no.2
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• pp.47-50
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• 2018

Purpose: Arirang, the most beautiful song in the world, has been meeting with natural healing to increase synergy. Arirang and nature healing have pioneered the field of Arirang music healing by crossing different boundaries. Methods: Arirang Gymnastics was used. Results: New Arirang Gymnastics is part of the healing of Arirang music, which consists of six movements. Starting with warm-up exercises in time for Seoul Arirang, the patient will apply pressure to the pit of the pit of the stomach, the head of the stomach, and the non-surface field. To match Haeju Arirang, massage the right side of abdomen, left side underbed, top (stomach), and lower bladder. Tap the Danjeon, the bladder, the heart, and the lungs in accordance with Millyang Ariryang. Stretching both arms and shoulders in line with Arirang in Gangwon Province, the two sides meet behind each other. Rotate the shoulders and wrists in line with the progress of the arm. Conclusions: Aerobic exercise that is tailored to new Arirang and their gymnastics are useful for health and healing of the body and mind.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.252-252
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• 2022

Genotype-by-environment interaction (GEI) refers to the comparative response of genotypes to different environments conditions. Thus, understanding GEI is a fundamental component for selecting superior genotypes for breeding programs. The significance of utilizing early maturing cultivars not only provides flexibility in planting dates, but also serves as an effective strategy to reduce methane emission from the paddy fields. In this study, we conducted multi-environment trials (METs) to evaluate yield-related traits such as culm length, panicle length, panicle number, spikelet per plant, and thousand grain weight. A total of eighty-one Korean commercial rice cultivars categorized as early maturing cultivars, were cultivated in three regions, two planting seasons for two years. The genotype main effect plus genotype-by-environment interaction (GGE) biplot analysis of yield-related traits and grain yield explained 70.02-91.24% of genotype plus GEI variation, and exhibited various patterns of mega-environment delineation, discriminating ability, representativeness, and genotype rankings across the planting seasons and environments. Moreover, simultaneous selection using weighted average of absolute scores from the singular value decomposition (WAASB) and multi-trait stability index (MTSI) revealed six highly recommended genotypes with high stability and crop productivity. The winning genotypes under specific environment can be utilized as useful genetic materials to develop regional specialty cultivars, and recommended genotypes can be used as elite climate-resilient parents to improve yield-potential and reduce methane emission as part to accomplish carbon-neutrality.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.308-316
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• 2023

Objectives: The aim of this study is to measure and assess the occupational noise exposure levels among construction workers at apartment building construction sites in South Korea. Methods: Noise exposure assessments were conducted for 139 construction workers across 10 different trades at 53 apartment building construction sites in the northern part of Gyeonggi-do. Assessments were carried out using a noise dosimeter set with a 90 dB criterion, an 80 dB threshold, and a 5 dB exchange rate over a period of more than 6 hours(L_MOEL) Results: The mean L_MOEL (equivalent continuous noise level over 8 hours) for the 139 dosimeter samples was 87.8 ± 4.3 dBA. The mean noise exposure level for each construction trade, referred to as the trade mean, was also calculated. Significant differences in noise exposure levels were observed between construction trades (ANOVA, p < 0.001). The highest L_MOEL values were recorded for concrete chippers (93.2 ± 2.6 dBA), followed by ironworkers (88.4 ± 0.7 dBA), concrete finishers (88.3 ± 2.7 dBA), masonry workers (87.7 ± 1.9 dBA), pile driver operators (85.6 ± 1.7 dBA), concrete carpenters (84.9 ± 2.4 dBA), interior carpenters (83.5 ± 2.1 dBA), and other groups (81.4 ± 2.2 dBA). Conclusions: The findings suggest that nearly all construction workers in this study are at risk of Noise-Induced Hearing Loss (NIHL). Moreover, the study establishes that construction trades can serve as a useful metric for assessing noise exposure levels at apartment construction sites.

• Journal of Species Research
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• v.12 no.4
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• pp.281-285
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• 2023

The red-tongue viper(Gloydius ussuriensis) is one of only three species of the genus Gloydius found in South Korea. Gloydius ussuriensis has a narrow activity radius and is distributed nationwide, and this species was reported to have the largest population among the Korean species in genus Gloydius. Preliminary results of a phylogenetic analysis using part of the mitochondrial DNA indicated that domestic G. ussuriensis is not comprised of monophyletic groups, and morphological analysis showed differences between domestic populations. In this study, we developed 17 microsatellites for the analysis of G. ussuriensis genetic diversity based on these characteristics. These microsatellites were developed using six multiplex panels, which could be employed to validate 80 G. ussuriensis specimens from different geographical regions in South Korea. The average number of alleles per locus was 12.2 and ranged from 4 to 25 alleles; the observed heterozygosity ranged from 0.238 to 0.950 and the expected heterozygosity ranged from 0.213 to 0.933. As a result of assessing four inland populations, a high level of genetic diversity was confirmed. These newly developed markers will be useful for further studies on the population structure and evolutionary history of the G. ussuriensis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.74-78
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• 2024

We have studied the effects of Ag on the characteristics of Sn₄₈In₅₂Ag_x (wt%) low-melting solders for photovoltaic ribbons. The Sn₄₈In₅₂ (wt%) solder coexisted in the InSn₄ and In₃Sn alloys. Ag atoms added in the solder formed an AgIn₂ alloy by reacting with some part of In atoms, while they did not react with Sn atoms. The addition of Ag atoms in the Sn₄₈In₅₂Ag_x (wt%) solders showed useful results; an increase in peel strength and a decrease in melting temperature. The peel strength of the ribbon plated with the Sn₄₈In₅₂ (wt%) solder was 53.6 N/mm², and that of the Sn₄₈In₅₂Ag₁ (wt%) solder largely increased to 125.1 N/mm². In the meanwhile, the melting temperature of the Sn₄₈In₅₂ (wt%) solder was 119.2℃, and that of the Sn₄₈In₅₂Ag₁ (wt%) solder decreased to 114.0℃.