• Explosives and Blasting
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• v.38 no.4
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• pp.46-52
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• 2020

Although anti-washout grouts are used extensively in underwater targets, major constraints continue to be associated with their use. These include poor bonding strength, poor pumpability, and loss of high strength in everyday engineering applications. In this study, based on the literature pertaining to self-compacted, non-dispersive, anti-washout grouts, a review of research trends in anti-washout grouts for underwater construction and sealing of karst cavities was carried out in order to determine the problems faced in this field. Grouts used under water suffer a loss of strength and bonding strength in comparison to grouts cast in air. Researchers are designing high-viscosity grouts to overcome the inrush of water and seal karst cavities; however, in doing so, they have inadvertently caused serious problems pertaining to the pumpability of these grouts and concretes in deep target locations. Thus, the majority of the anti-washout grouts and concretes that have been developed are not applicable to deep target environments, instead being suitable for only near-surface targets.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.519-528
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• 2020

This study is a study on the relationship between brand trust in beauty companies leading to consumer loyalty behavior. This study investigated the importance of brand trust and verified the moderating effect of brand awareness. The subjects of the survey were consumers with experience in using hair beauty services, and a self-written survey was conducted from December 15, 2019 to December 30, 2019. A total of 288 copies of response data were used for analysis, and the SPSS 21.0 statistical package program was used. Hairshop brand trust was classified into professionalism, favorability, and honesty. As a result of the analysis, professionalism had a significant effect on economic loyalty behavior, and honesty had a significant effect on economic loyalty behavior and social loyalty behavior. Favorability did not show an influence relationship. As a result of verifying the moderating effect of brand awareness, it was found that professionalism and honesty play a moderating effect in the influence relationship between social loyalty behaviors. This study aims to provide an effective direction to stably establish the relationship between the brand trust and customer relationship of the hair shop in a rapidly changing competitive environment.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.453-460
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• 2020

Bolboschoenus planiculmis is an important prey species for winter migratory birds in the Nakdong River Estuary region, but its population has declined in the last decade due to a physio-chemical shift. To identify the growth and development characteristics of B. planiculmis, we carried out an experimental survey on the aboveground and belowground sections of B. planiculmis specimens in the Eulsuk tidal flat from April to September 2019. We divided the belowground area into two groups: a vegetation group in which B. planiculmis exists and a non-vegetation group in which B. planiculmis does not exist and measured the rate of tubers. We observed a 45% appearance frequency in the vegetation group and only a 5% frequency in the non-vegetation group, indicating that there were no supplies for plant growth. The mean density, length, and biomass of B. planiculmis aboveground were 166.90±149.62 n m^-2, 44.39±5.45 cm, and 67.63±54.46 g DW m^-2, respectively, which was approximately half of those obtained from the study in the Eulsuk tidal flat in 2002. Tuber number was the highest in the 15~25 cm deep layer(41.50%). The mean number of total tubers belowground was related to different sediment conditions(FS: flat surface, DS: disturbed surface) 251.75±16.86 n pot^-1 for FS and 171.00±25.18 n pot^-1 for DS, which was significantly different(total tubers: p<0.005). The mean biomass of B. planiculmis above-ground was 21.11±1.60 g DW pot^-1 for FS and 15.41±1.38 g DW pot^-1 for DS, which was significantly different(p<0.05). This research provides primary materials for the restoration of the Nakdong River Estuary, wintering sites for migratory birds, and protection of B. planiculmis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.215-226
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• 2021

The purpose of this study is to examine the relevance of resilience, which is one of the internal psychological competencies, in the relationship between the adult attachment of university students and their career barriers. A total of 300 university students from across the country were surveyed online through a specialized research firm over the period from November 10, 2019 till November 20, 2019. The data were analyzed using AMOS 23.0 and SPSS 23.0 suites, and the study findings were as follows. The adult attachment of university students firstly had a negative impact on resilience and secondly a positive impact on the career barriers. Third, the resilience of the university students had a negative impact on the career barriers. Fourth, in the influence of the adult attachment of university students on career barriers, resilience had a mediating effect to mitigate career barriers. With this study, it is expected that an environment where the information and training on desirable attachment at home and school can be provided, while educational supports can be examined for the development of the programs that can enhance their self-competency, including career education.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.5
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• pp.65-72
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• 2021

700 W class laboratory model Hall thruster, which can be used for the orbit control or station keeping of small satellites, was developed. The size of the discharge channel was determined using a scaling law, and the magnetic field was designed to be symmetric with respect to the midline of the discharge channel and to be maximized outside the discharge channel. Base pressure of a vacuum chamber was maintained below 2.0×10^-5 Torr during experiments, and the thrust was measured by a thrust stand. The anode flow rate and coil current were varied with the fixed anode voltage at 300 V. Under the operation condition at 2.36 mg/s anode flow rate and 2.4 A coil current, performance was optimized as 38 mN thrust, 1,540 s total specific impulse, and 50 % anode efficiency at 620 W anode power.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.63-70
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• 2022

Due to the recent changes in the education market and Corona, Consumers have moved to the tutoring and online learning markets, and the large-scale education service franchise business is reorganized into a small-scale franchise, a business model that maximizes the profit structure from a position where sales are important. Recently, a new learning balance model that can provide individualized services from teacher-centered to student-centered, motivate students is required. In this paper, we propose a new mathematical franchise model (K-MODEL) that can improve a company's profit structure while satisfying the recent education trends and consumer needs from the point of view of the franchise. K-MODEL expects franchisor and franchisees to have a stable profit structure by developing differentiated content and services, learning and operating processes, and various programs to improve learning achievement.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1355-1362
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• 2021

Recently, not only congenital hearing impairment, but also the number of people with hearing impairment due to acquired factors is increasing. The environment in which sign language can be learned is poor. Therefore, this study intends to present a sign language (sign language number/sign language text) evaluation system as a sign language learning assistance tool for sign language learners. Therefore, in this paper, sign language is captured as an image using OpenCV and Convolutional Neural Network (CNN). In addition, we study a system that recognizes sign language behavior using MediaPipe, converts the meaning of sign language into text-type data, and provides it to users. Through this, self-directed learning is possible so that learners who learn sign language can judge whether they are correct dez. Therefore, we develop a sign language learning assistance system that helps us learn sign language. The purpose is to propose a sign language learning assistance system as a way to support sign language learning, the main language of communication for the hearing impaired.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.239-251
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• 2022

This study investigated the purchase intention of TikTok Live Commerce users by applying the Decomposed Theory of Planned Behavior(DTPB). This study conducted a survey of 512 users with experience in purchasing TikTok Live Commerce in China. Result of the analysis, first, it was found that attitudes, subjective norms, and perceived behavioral control all had effect on the purchase intention of TikTok live commerce. Second, it was found that perceived usefulness, interactivity, and perceived enjoyment had a positive effect on attitudes, but perceived ease did not have a statistically significant effect. The third,friend was found to have an effect on subjective norms. It was found that self-efficacy had a significant effect on perceived behavior control, but the facilitating condition did not significantly affect perceived behavior control.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.431-438
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• 2022

In functional materials, in situ experimental techniques as a function of external stimulus (e.g., electric field, magnetic field, light, etc.) or changes in ambient environments (e.g., temperature, humidity, pressure, etc.) are highly essential for analyzing how the physical properties of target materials are activated/evolved by the given stimulation. In particular, in situ electric-field-dependent X-ray diffraction (XRD) measurements have been extensively utilized for understanding the underlying mechanisms of the emerging electromechanical responses to external electric field in various ferroelectric, piezoelectric, and electrostrictive materials. This tutorial article briefly introduces basic principles/key concepts of in situ electric-field-dependent XRD analysis using a lab-scale XRD machine. We anticipate that the in situ XRD method provides a practical tool to systematically identify/monitor a structural modification of various electromechanical materials driven by applying an external electric field.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.127-138
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• 2022

In this paper, we present FinDID (Financial Decentralized IDentity), a blockchain-based DID(Decentralized IDentity) service that can flexibly control personal information or credentials through a systematic verification method while complying with the standard service scheme of decentralized identity for the financial sector. DID is an identity management system used in a decentralized environment without a specific certification authority, and as a technology that allows users to control their own information, it can realize self-sovereignty over users' own personal information. Through FinDID, users receive credentials that authenticate their various personal information from the issuer, select only the claims required by the target financial service using their personal electronic wallet, create presentations from credentials. Then they submit it to the financial service, leading to their qualification from the service. FinDID consists of electronic wallet, credential issuer, credential storage, DID service including DID management contract and credential management contract, and financial services using this service scheme. The DID service manages each user's DID and supports all verification processes of the associated identity management scheme.