• Macromolecular Research
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• v.14 no.2
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• pp.209-213
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• 2006

The ring-opening polymerization of D,L-lactide initiated by tin(II) 2-ethylhexanoate $(Sn(Oct)_2)$ on the surface-initiated magnetite $(Fe_{3}O_4)$ nanoparticles was performed at $130^{\circ}C$. The effects of the polymer molar mass and concentration on the amount of surface polymer were investigated. The number average molecular weights, $M_n$, obtained by both NMR and GPC methods fit well within the accuracy of the applied methods and ranged from 1,100 to $4,040g\;mol^{-1}$. A surface functionalization density of up to 625 initiation sites per particle was obtained. The composition of various core-shell particles was determined by TGA, with results indicating magnetite $(Fe_{3}O_4)$ contents, ${\mu}m$, between 17 and 59 wt%. Under the influence of a magnetic field, the heating generated by superparamagnetic core-shell particles suspended in toluene presented guidelines for an optimization of magnetic particle systems with respect to an application for hyperthermia.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.66-76
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• 2020

We The 4th industrial revolution, the core characteristics of super-intelligence, hyper-connective, and ultrareality, has been actualized. New technologies such as artificial intelligence, big data, the Internet of Things, and high-tech video have begun to be applied to media and advertising. With the introduction of new technologies in the advertising field, innovative changes in advertising types, advertising effects, advertising methods, and advertising contents are expected. Accordingly, We intends to design a future advertising roadmap development by predicting how future advertising will change and develop through future technologies in the 4th industrial revolution era. To design the roadmap, this study analyzes changes in advertising technology, consumer, and media as changes in the advertising environment in the 4th industrial revolution era, and identifies the core changing trends, advertising factors in future advertising through the Delphi Survey on experts in advertising and future fields. We identifies how the future advertising technology, types, media, effects, and fields are developed by the changes of future advertising environments, including technology, consumers, and media in the 4th industrial revolution era. Hence it is expected to help the advertising industry and experts to prepare for future changes.

• Journal of Welding and Joining
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• v.29 no.1
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• pp.90-98
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• 2011

Al-Si coated Boron steel and Zn coated DP steel were welded using DISK laser and the microstructure and hardness of the weld were investigated. Full penetration was obtained, when the welding speed was lower than 4m/min. In the specimen welded with laser power of 3 kW and welding speed of 2 m/min, the hardness was the highest in the heat affect zone in the boron steel (HAZ-B) and that of the heat affect zone in the DP steel (HAZ-D) was lower than HAZ-B. The hardness of fusion zone was in between those of HAZ-B and HAZ-D. The decreased hardness from each HAZ to base metal(BM) could be explained that ferrite contents increases when access to the BM. The variation of hardness in the welds could be explained by the difference of microstructure, that is, full martensite in HAZ-B, mixture of martensite and bainite in the fusion zone, and the mixture of martensite, ferrite and bainite in HAZ-D.

• Journal of the Korean Society for information Management
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• v.18 no.2
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• pp.57-76
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• 2001

As the rapid develoment of internet and information technology, the traditional library has been altered to the digital content service based on the world wide web. This paper proposes a design and implementation of an Artcle Union Catalog System(AUCS) based on metadata. The metadata set for the AUCS consists of twelve Dublin Core elements and one holdings element. The qualifiers of the proposed metadata elements are also represented. The AUCS system has an online cooperated cataloging system using the web interface or the 239.50 protocol, an union cataloging management system, and an integrated information retrieved system service. The integrated search and retrieval service of the AUCS displays not only the summary and detailed bibliographic information, but also the abstract, the table of contents, the digital content, and the copylfax service.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.44-50
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• 2006

Contents of phenolic compounds in peel, flesh, and core of three Asian pear cultivars, Hosui, Niitaka, and Chuwhangbae, were determined at different stages of maturity. Antioxidant properties of methanol extracts of peels at various fruit maturity stages were also evaluated. Total phenolic content decreased with maturity. Arbutin, chlorogenic acid, and epicatechin were major phenolic compounds in young fruits. Catechin, 4-hydroxymethyl benzoic acid, and caffeic acid were detected in peel and core of immature and mature pears. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of methanol extracts were 16.30 and $15.73\;{\mu}g$ in peel of immature Hosui and Chuwhangbae pears, respectively, and $11.59\;{\mu}g$ in mature Niitaka pears, which was significantly higher than those of other maturity stage in the same cultivar. Inhibitory activities on lipid oxidation of methanol extracts of three cultivars at all maturity stages were similar to that of ${\alpha}$-tocopherol.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.763-780
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• 2012

The purpose of this study was to develop the teaching & learning model to increase the key competencies in the university. For this, the researcher suggested the draft of teaching & learning model in the university based on literature analysis and survey for key competencies education to professors and students. After that, the draft of the model was revised through the formative test by experts. And then, the revised model was verified through delphi survey and a final model was fixed. As the result of this study, features of the final model are as follows. First, this study identified that a core values of teaching and learning model for the key competencies education in the university is reinforcement of learner's thinking skills and enhancement of field oriented on learning contents and reinforcement of professor's role as a mentor, a facilitator, a motivator, and an informant. Second, The core learning activity's process of the teaching and learning model for the key competencies education in the university consists of the following in order: team-building, exploring problem, gathering and analysing informations, arranging of leaning outcomes, comprehensive arrangement and self-examination.

• Perspectives in Nursing Science
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• v.17 no.1
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• pp.28-39
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• 2020

Purpose: To understand the core elements and the effects of interventions on the improvement of parenting capabilities of unmarried mothers living in residential facilities, this study reviewed the literatures related to this concept. Methods: Five electronic databases (KISS, KMbase, KoreaMed, NDSL, and RISS) were searched, and eight studies were ultimately selected for the integrative review. Results: The interventions were categorized into two types: psychological intervention and sociocultural intervention. The core elements of the psychological interventions included cognitive, emotional, behavioral, and relational contents. Sociocultural aspects included raising personal skills for finding social support resources. Various studies showed the effects of intervention on efficacy, attachment, or parenting behavior. Conclusion: Based on the results of this study, health promotion programs to improve maternal parenting competency for unmarried mothers living in residential facilities need to be developed and applied.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.445-449
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• 2010

The purpose of this study is to improve recycling rate of the waste glasses by investigating bloating mechanism. In this study, we use waste glass(W/G) and hard clay(H/C) as raw materials. The artificial lightweight aggregates were formed by plastic forming($\phi$=10 mm) and sintered by fast firing method at different temperatures(between 700 and $1250^{\circ}C$). The physical properties of the aggregates such as bulk specific gravity, adsorption and microstructure of surface and cross-section are investigated with the sintering temperature and rate of W/G-H/C contents. As the result of the bulk specific gravity graphs, we can found out the inflection point at content of W/G 60 wt%. From the microstructure images, we considered the artificial lightweight aggregates content of W/ G over 60wt% are distributed numerous micro-pores by organic oxidation without Black Core and the artificial lightweight aggregates of W/G below 60 wt% are distributed macro-pores with Black Core.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.2
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• pp.1-10
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• 2018

Objectives: The purpose of this study is to expand of workplace by analyzing the duty and workplace of health education specialist and by presenting professional duty for health education specialist. Methods: 22 papers related to health education experts were finally selected from 1993 to 2017(25 years). The selected literature analyzed the title, researchers, the publishing agency, the publication year, the main contents, and duty and workplace of the health education specialist. Results: The studies on health education specialists comprised 5 cases (22.7%) between 1993 and 1999, 3 cases (13.6%) between 2000 and 2009, 14 cases (63.6%) between 2010 and 2017. Health education specialists core duty were diagnosing health education needs, planning health education programs, developing health education methods and materials, performing and managing health education programs, evaluating and conducting research on health education programs, and health communication. The workplace were 11 for medical institutions (55.0%), 9 for healthcare organizations (45.0%) and 8 for schools (40.0%). Conclusions: In addition to the basic core duty, professional and differentiated duty capabilities such as managing the target, generating health information, encouraging involvement of the target, and mobile health care should be developed.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.3-11
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• 2021

The construction project manager must clearly carry out the activities of each construction stage specified in the 'Task Description'. In this study, 'design change' and 'completion process' were classified as core tasks in consideration of the frequency and importance of tasks. And, by analyzing the actual construction project, the task contents for the core work were standardized. This laid the foundation for the ordering office, construction project management technicians, and builders to clearly understand the business areas of construction project management and fulfill their responsibilities for their respective tasks.