• 펄프종이기술
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• 제44권2호
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• pp.67-73
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• 2012

Structural stability and shock absorption are important properties for corrugated board. In order to maintain structural stability, adhesive properties between top/bottom liners and corrugated medium are not only essential but also important for productivity and product quality. Borax has been an essential ingredient in corrugating adhesive solution. Borax increases viscosity, bonding between starchs and green adhesive bond. The objective of this research is to improving adhesive strength and viscosity stability by adding cross-linking agent instead of borax. Rheology and penetration of main starch gelatinization slurry were affected by borax addition level. Borax increased viscosity and decreased viscosity stability, while cross-linking additives increased viscosity stability and adhesive strength by anchoring effect.

• 펄프종이기술
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• 제44권3호
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• pp.15-21
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• 2012

The optimum dewaxing ratio in dewaxing treatment by the heat and pressure method was investigated by considering aging stability of dewaxed Hanji. Commercial Hanji was coated with beeswax and thermally aged at $150^{\circ}C$ for 24 hours. Then it was dewaxed using the laboratory sheet press equipped with hot plates on both top and bottom sides. Dewaxing ratio was controlled by pressing temperature and time. Four type of dewaxed Hanji samples with different dewaxing ratio were prepared and thermally aged at $150^{\circ}C$. Then the aging stability of dewaxed Hanji samples was evaluated in terms of optical and strength properties. It was found that the aging stability of dewaxed Hanji was superior with higher dewaxing ratio. The result concluded that, in the aspect of aging stability, the coated beeswax in beeswax-treated Hanji shall be completely removed if the coated wax would be dewaxed.

• 펄프종이기술
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• 제43권3호
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• pp.11-20
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• 2011

The conditions to which pulp fibers are exposed during paper production, converting, storage, use, and recycling can induce various changes in fiber morphology, surface characteristics, and suitability for paper production by recycled fibers. Most of those changes can be described by hornification. Paper has highly hygroscopic properties which affect dimensional change by relative humidity variation of surrounding condition. The purpose of this study was to investigate the dimensional stability, moisture contents and dip elongation of handsheets at different relative humidity conditions of recycled kraft pulp and BCTMP. By using recycled fibers, dimensional stability was increased because hygroscopic properties of fibers decreased with repeated recycling treatment. Dip elongation of recycled pulp was higher than that of virgin pulp because of its weak fiber-to-fiber bonding. By recycling pulp, the relative bonded area was decreased because fiber could not swell more than virgin pulp. Dimensional stability largely depended on the equilibrium moisture contents of paper, the fiber-to-fiber bonding strength, and the relative bonded area.

• 한국산업융합학회 논문집
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• 제25권3호
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• pp.357-363
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• 2022

In this study, in order to develop an non-slip metal grating, the stability of the grating according to the span of the grating and the gap and height of the bearing bar was evaluated. The optimal shape design of the grating was performed using the results of determining the stability of the grating. The purpose of this study is to determine the stability according to the spacing and height of the bearing bar by applying the design pressure at the design stage to develop the anti-skid grating, and to design the optimal shape for cost reduction. In the optimal design, the target variable was set as the mass, and the optimal design of the grating was performed based on about 20%. Regardless of the height of the bearing bar of the grating, the stress and deformation of the span and the grating showed a proportional tendency to each other, and it was found that the stress decreased as the height of the bearing bar increased. Based on the structural analysis results, an optimal design was performed using mass as the objective variable, and the existing 2mm thickness was changed to 1.6mm, reducing the mass by about 19%. The stress increased by about 4.4% compared to the maximum stress of the existing grating, but the minimum safety factor was 3.1, indicating that the optimally designed grating was stable.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1155-1163
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• 2022

This study proposes a technology to ensure the seismic stability of a 1,000 kW diesel engine-type emergency generator by applying a seismic isolated bed system. The technology allows the static analysis by making the first natural frequency of the installed entire emergency generator larger than the earthquake cutoff frequency of 33 Hz. First a three dimensional model for the generator was made with simplification for mode analysis. A new bed system with springs, shock absorbers, stoppers was then devised. Next, The mode analysis for the finite element model equipped by the bed system was performed. the 1^st natural frequency above 33 Hz, the seismic safety cutoff frequency, was calculated to be 152.92 Hz. Finally, based on the seismic stability theory, the von-Mises equivalent stresses derived by structural analysis under the Upset and Faulted conditions were 0.01603 Mpa, and 32.06 Mpa, respectively. so seismic stability was confirmed.

• 한국산업융합학회 논문집
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• 제27권1호
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• pp.161-172
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• 2024

Approximately 89% of all capsizing accidents involve small vessels, and despite their relatively high accident rates, small vessels are not subject to ship stability regulations. Small vessels, where the provision of essential basic design documents for stability calculations is omitted, face challenges in directly calculating their stability. In this study, considering that the majority of domestic coastal small vessels are of the Chine-type design, the goal is to establish the major hull form characteristic data of vessels, which can be identified from design documents such as the general arrangement drawing, as input data. Through the application of a deep learning approach, specifically a multilayer neural network structure, we aim to infer hydrostatic curves, operational draft ranges, and more. The ultimate goal is to confirm the possibility of directly calculating the initial stability of small vessels.

• Advances in nano research
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• 제17권2호
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• pp.167-179
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• 2024

This study investigates the stability and performance of high-resistance badminton nets through the integration of reinforced lightweight materials. By focusing on the structural and economic impacts, the research aims to enhance both the durability and practicality of badminton nets in professional and recreational settings. Using a combination of advanced material engineering techniques and economic analysis, we explore the development of nets constructed from innovative composites. These composites offer improved resistance to environmental factors, such as weather conditions, while maintaining lightweight properties for ease of installation and use. The study employs high-order shear deformation theory and high-order nonlocal theory to assess the mechanical behavior and stability of the nets. Partial differential equations derived from energy-based methodologies are solved using the Generalized Differential Quadrature Method (GDQM), providing detailed insights into the thermal buckling characteristics and overall performance. The findings demonstrate significant improvements in net stability and longevity, highlighting the potential for broader applications in both the sports equipment industry and related economic sectors. By bridging the gap between material science and practical implementation, this research contributes to the advancement of high-performance sports equipment and supports the growth of the sport economy.

• 산업노동연구
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• 제23권1호
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• pp.197-220
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• 2017

본 논문은 비선형 해저드 모형을 이용해 산업별 수입침투율 상승이 개별 노동자의 일자리 중단 확률에 미친 영향을 실증적으로 분석한다. 주요 결과는 다음과 같다. 첫째, 수입침투율 상승은 일자리 안정성에 상당히 크고 통계적으로 유의한 부정적 영향을 미친다. 산업 총공급 대비 수입 비중이 1%p 증가하면 해당 산업에서 일하는 노동자들의 이직 확률은 4.5%p 증가한다. 둘째, 무역자유화의 효과는 수입과 수출 간에 비대칭적이다. 수입침투율의 경우와 달리 수출의존도가 일자리 안정성에 미치는 영향은 통계적으로 유의하지 않다. 셋째, 수입침투율이 일자리 안정성에 미치는 부정적 효과의 크기는 노동자 특성에 따라 다르다. 중소기업과 무노조 기업에 속한 노동자와 저학력 노동자가 더 큰 부정적 영향을 받는다.

• 한국산업융합학회 논문집
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• 제27권1호
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• pp.229-237
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• 2024

The logistics industry is converging with digital technology and growing into various logistics automation systems. However, inspection and loading/unloading, which are mainly performed in logistics work, depend on human resources, and the workforce is shrinking due to the decline in the productive population due to the low birth rate and aging. Although much research is being conducted on the development of automated logistics systems to solve these problems, there is a lack of research and development on load stacking stability, which has the potential to cause significant accidents. In this study, loading boxes with various sizes and positions of the center of gravity were set up, and a method for stacking that with high stability is presented. The size of the loading box is measured using a depth camera. The loading box's weight and center of gravity are measured and estimated by a developed device with four loadcells. The measurement error is measured through various repeated experiments and is corrected using the least squares method. The robot arm performs load stacking by determining the target position so that the centers of gravity of the loading boxes with unbalanced masses with a random sequence are transported in alignment. All processes were automated, and the results were verified by experimentally confirming load stacking stability.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2002년도 추계학술발표논문집
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• pp.209-217
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• 2002

Stability deterioration of AKD emulsion was studied with respect of the physical change of emulsion particles and the chemical change of AKD itself. Four kinds of commercial emulsions were kept at RT, 40, 50, and $60^{\circ}C$ water bath, respectively. Viscosity, particle size distribution, and solid contents of the emulsions were measured with storage time. At the same time, by performing NMR and IR spectroscopy analysis of the solvent-extracted AKD from the emulsions, the qualitative and quantitative information about the deformation of the AKD itself were obtained. AKD was gradually hydrolyzed to become dialkylketone and higher storage temperature accelerated destabilization of the AKD emulsions.