• 펄프종이기술
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• 제43권2호
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• pp.40-48
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• 2011

To build up the conservativeness of aged paper heritages, the strength reinforcement treatment using various cellulose derivative solutions was considered. Hand-made Hanji prepared by traditional papermaking technique was firstly simulated in order to modify the overall of paper properties like aged paper heritages by accelerated ageing treatment at $150^{\circ}C$ for 24 hours, and then the ageing stability of Hanji was verified through the secondary accelerated ageing at $150^{\circ}C$ for 12 hours. The physical properties of aged Hanji were improved by applying with cellulose derivative solutions. The ageing stability for physical, optical (L, brightness, opacity, yellowness) and chemical (oxidation index, degree of polymerization) properties of aged Hanji treated with all kinds of cellulose derivative solutions was also good compared to those of untreated samples, especially using MC solution. Therefore, it was that a kind of MC solution would be well-suited for the strength reinforcement treatment of aged paper heritages.

• 펄프종이기술
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• 제43권2호
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• pp.66-71
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• 2011

Biocomposites were fabricated with biodegradable polymers and natural fibers. Biocomposites have benefits of low cost, low density, and biodegradability over inorganic fiber composite, and give comparable strength properties. Hydrophobic polymer used for sizing in paper industry, AKD (Akenyl Keten Dimer), was applied to natural fibers, red algae fibers (RAF) in this study, to make fiber surfaces more compatible to hydrophobic nature of matrix polymers. Composites with RAF, kenaf, glass fibers, and carbon fibers have been fabricated by a compression molding method and their thermo-mechanical properties have been studied. Also, the thermal dimensional stability test was done from at 30 to $100^{\circ}C$. The storage moduli and the thermo-mechanical stabilities of polypropylene and poly lactic acid based biocomposites were improved by reinforcing with the RAF and much more with AKD treated fibers. Dimensional stability of biocomposite was also markedly improved by AKD pretrement on RAF.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.119-126
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• 2021

The study develops methodological aspects for modeling the determining impact of modernization on the enterprise's economic security in development competitive conditions using the model of speed, stability and spaciousness of modernization. Modeling the determining impact of modernization on the enterprise's economic security in a competitive conditions involves: firstly, the formation of estimated modeling indicators in accordance with the speed, stability and spaciousness of the enterprise's modernization; secondly, establishing the weight of indicators in the assessment system using the tools of cognitive judgment; thirdly, the establishment of reference values of sound evaluation indicators; fourthly, the calculations of the integrated impact assessment of the modernization's determining impact modeling on the enterprise's ensuring economic security in a competitive conditions; fifthly, conducting calculations and analytical summarization of the results. To determine a comprehensive integrated indicator of the modernization changes impact on the competitiveness and economic security of enterprises, we use the correlation method of the calculated value with the reference value, as well as use weights for groups of calculations. Approbation of modeling of determining influence of modernization on maintenance of economic safety of the enterprise in competitive conditions of development by authors was carried out concerning such enterprises, as: JSC "Ukrzaliznytsia", SE "Ukraerorukh", SE IA "Boryspil", SE "Ukrposhta", KP "Kyivpastrans".

• Advances in nano research
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• 제16권5호
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• pp.445-458
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• 2024

The objective of this paper is to present free vibration and static stability analyses of rotating composite beams reinforced with carbon nanotubes (CNTs) under uniform thermal loads. Beam structural equations and CNT-reinforced composite (CNTRC) beam formulations are derived based on Timoshenko beam theory (TBT). The temperature-dependent properties of the beam material, such as the elastic modulus, shear modulus, and material density, are assumed to vary over the thickness according to the rule of mixture. The beam material is modeled as a mixture of single-walled carbon nanotubes (SWCNTs) in an isotropic matrix. The SWCNTs are aligned and distributed in the isotropic matrix with different patterns of reinforcement, namely the UD (uniform), FG-O, FG-V, FG- Λ and FG-X distributions, where FG-V and FG- Λ are asymmetric patterns. Numerical examples are presented to illustrate the effects of several essential parameters, including the rotational speed, hub radius, effective material properties, slenderness ratio, boundary conditions, thermal force, and moments due to temperature variation. To the best of the authors' knowledge, this study represents the first attempt at the finite element modeling of rotating CNTRC Timoshenko beams under a thermal environment. The results are presented in tables and figures for both symmetric and asymmetric distribution patterns, and can be used as benchmarks for further validation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2519-2523
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• 2008

When constructing a high-speed railroad, the reduction of the distance between track centers and the width of track bed will save the construction cost. However the shortening the distance between track centers may cause the stability problems due to higher wind pressure. Therefore the extensive technical review and aerodynamical study should be performed to determine the adequate distance between track centers. In this study, the impact that the increase in wind pressure due to the change of aerodynamic phenomena with the change of the distance between track centers may have on two trains passing by each other was predicted, and the stability of train operation was analyzed in order to review the distance between track centers suitable to Honam HSR trains. We conducted the parametric study of the effects of train wind on the running stability.

• Structural Engineering and Mechanics
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• 제6권7호
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• pp.747-756
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• 1998

In this paper the influence of rotary inertia, shear and compressibility on the value of the critical force for the Beck's column is analyzed. The constitutive equation is of Engesser's type. As a result, the critical load parameter for which instability of flutter type occurs is calculated for several values of the column's parameters.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(B)
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• pp.385-387
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• 2011

본 논문은 철강 공정을 위한 로그서버의 구조를 설계하였다. 제안된 로그서버는 기존에 개발된 철강공정용 레벨 2 표준 미들웨어인 POSMOS 미들웨어의 특정 Agent 기능을 활용하여 독립적으로 구현됨으로써, 로그 활용을 위한 시스템 부하를 줄이고, 분산환경 아래에서의 통합적인 로그 수집이 가능하도록 설계 되었다. 본 로그 서버를 통한 로그 관리는 무정지 환경 아래의 철강 공정의 시스템의 안정성 확보를 위해 활용될 예정이다.

• 펄프종이기술
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• 제33권2호
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• pp.74-80
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• 2001

This study was carried out to manufacture microcapsules from natural aromatic essential oils by polymeric emulsification and to evaluate their properties using microscopical and electro-chemical analysis techniques. It was shown that aromatic essential oils (yuja, lavender, and peppermint) could be microcapsulated and their emulsion has a good stability and storage characteristics.

• 펄프종이기술
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• 제34권5호
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• pp.70-76
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• 2002

Ten years ago most papermakers were convinced that a system needs to be voluminous and heavy for controllability and stability. In order to improve grade changing dynamics, the author of this paper began developing a compact papermachine wet end. The results have proven that compactness is beneficial even more broadly. Quoting Voith$^1$the trend is now the opposite - the systematic collecting and direct feeding of the individual water flows back into the system". In its gasless form this is actually covered by a POM Technology Patent.tent.

• 한국항해항만학회지
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• 제34권10호
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• pp.807-815
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• 2010

본 연구는 RIFD를 게이트에 적용하여 활용하고 있는 컨테이너터미널을 대상으로 게이트에서 RFID 수용의도와 적용성과간의 관계를 확인하기 위하여 실증분석을 실시하였다. 먼저, 주요 이론 및 선행연구들을 바탕으로 RFID를 게이트 적용 시에 수용의도에 영향을 미치는 요인으로 기술안정성, 시스템 품질, 보안성 등을 도출하였고, 도출된 요인들 중 RFID 게이트 적용 시 수용의도에 영향을 미치는 요인을 확인하고, RFID 수용의도와 적용성과간의 관계를 설문조사를 통하여 수집된 자료를 바탕으로 가설검정을 실시하였다. 연구결과, 기술 안정성을 제외하고 시스템 품질, 보안성은 RFID 수용의도에 유의한 영향을 미치고, RFID 수용의도는 RFID 적용성과에 유의한 영향을 미치는 것으로 나타났다.