• Structural Engineering and Mechanics
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• 제66권5호
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• pp.595-608
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• 2018

This paper deals with the lateral - torsional motion of bridges provided with external cables acting as dampers under the action of horizontal dynamic loads or of walking human crowd loads. A three dimensional analysis is performed for the solution of the bridge models. The theoretical formulation is based on a continuum approach, which has been widely used in the literature to analyze bridges. The resulting equations of the uncoupled motion are solved using the Laplace Transformation, while the case of the coupled motion is solved through the use of the potential energy. Finally, characteristic examples are presented and useful results are obtained.

• 펄프종이기술
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• 제36권5호
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• pp.21-28
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• 2004

Com stalk was evaluated to verify the potential as a raw material for papermaking. The lower lignin content and higher hemicelluloses content of cornstalk than any woods were considered to be beneficial for pulping and strength properties of paper. The average fiber length of com stalk was similar to those of hardwood, but longer fiber fraction is little bit included. It was found that the refining of pulp can be eliminated because of higher hemicelluloses content and narrower fiber characteristic. Disadvantages of cornstalk pulp were lower bulk and opacity, but it can be overcome by the proper use of wood pulp and filler.

• Journal of Information Processing Systems
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• 제14권2호
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• pp.448-454
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• 2018

Artificial bee colony (ABC) algorithm has attracted significant interests recently for solving the multivariate optimization problem. However, it still faces insufficiency of slow convergence speed and poor local search ability. Therefore, in this paper, a modified ABC algorithm with bees' number reallocation and new search equation is proposed to tackle this drawback. In particular, to enhance solution accuracy, more bees in the population are assigned to execute local searches around food sources. Moreover, elite vectors are adopted to guide the bees, with which the algorithm could converge to the potential global optimal position rapidly. A series of classical benchmark functions for frequency-modulated sound waves are adopted to validate the performance of the modified ABC algorithm. Experimental results are provided to show the significant performance improvement of our proposed algorithm over the traditional version.

• 펄프종이기술
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• 제38권4호
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• pp.31-40
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• 2006

Presence of old newspapers printed with waterbased flexographic inks leads to a significant loss of brightness of the deinked pulp by flotation process. It has been shown that neutral or acidic flotation deinking has many advantages in recycling of flexo printed newsprints. A comparative experimental study was performed to evaluate the deinking efficiency of three alcohol type deinking agents in flotation deinking of flexo printed newspapers. Zeta potential of neutral deinked pulp was less negative than alkaline deinked pulp. Also neutral deinking was advantages in reducing turbidity, COD, and cationic de-mands of deinking process water.

• 펄프종이기술
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• 제48권2호
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• pp.83-90
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• 2016

Increasing the amount of filler in paper is of high interest for paper industry while maintaining its key sheet quality properties. In this study, a MFC-GCC composite, made through a co-grinding NBSK (Northern bleached softwood kraft) pulp with a ground calcium carbonate (Intracarb 60), was used as a strength aid in paper in order to evaluate a potential cost reduction through filler increase without sacrificing paper quality. Hand-sheets were made of NBSK and/or eucalyptus pulp by using white water recirculation in a Tappi sheet former and was compared its properties without or with MFC additions at different filler levels. It was found that the MFC-GCC composite has a large surface area compared to the fiber, allowing the formation of more hydrogen bonds in the web, thus giving natural strength to the paper. Overall results are encouraging that the MFC-GCC composite allows papermaker to reduce basis weight and maintain critical sheet properties.

• Geomechanics and Engineering
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• 제15권6호
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• pp.1219-1225
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• 2018

In this study, a comprehensive laboratory experimental programme was conducted on expansive soil with a high swelling potential to study the influence of different additive materials on swelling pressure and index properties. Lime, sand, multifilament fiber and fibrillated fiber were used for stabilization of expansive soil. Lime, sand and fibers were respectively added to the expansive soil at 0-7%, 0-80%, 0-0.5%. On each mixture that was prepared by the proportions mentioned above, Atterberg limits, compaction, and swelling pressure tests were conducted. From the result of these experiments, the swelling pressure-time relation could be replaced by a rectangular hyperbola established to facilitate the prediction of ultimate percent swelling with a few initial data points. The best type of additive and its optimum ratio for engineering purposes could be estimated rapidly by this approach.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.107-113
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• 2001

Consumer Product compounds are used in homes and disposed in wastewater where they typically receive waste treatment. After treatment, sludge and effluent are released to the environment resulting in the potential exposure of terrestrial and aquatic organisms to these compounds. To ensure the environmental safety of these compounds, the environmental risk posed by chemicals released into the environment must be assessed. A reasonable, consistent and cost-effective method to conduct environmental risk assessments and to prioritize testing of these chemicals is needed which addresses risk to organisms residing in the terrestrial and aquatic compartments of the environment. This paper provides a fundamental understanding of the technical basis of environmental risk assessment using the major surfactant(i.e., LAS) used in the laundry detergent industry worldwide as a case study.

• 펄프종이기술
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• 제35권3호
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• pp.29-36
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• 2003

Reducing the energy consumption while maintaining pulp quality is an important objective of today's paper industry. Enzymatic treatment of fibers and the application of dry strength agent were investigated as methods to reduce energy consumption during refining and to upgrade fiber characteristics. Modification of recycled fibers with an enzyme was effective in improving relining efficiency and reducing refining energy. Optimization of dry strength agent application conditions including stock pH, cationic demand, zeta potential, etc. were found to be very important for improving its effectiveness.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.280-287
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• 2002

We present technical issues involved in the development of actuators and sensors for applications to high-precision Micro Electro Mechanical System (MEMS). The technical issues include fabrication uncertainty and noise disturbance, causing major difficulties for MEMS to achieve high-precision actuation and detection functions. For nano-precision actuators, we solve the fabrication instability and electrical noise problems using digital actuators coupled with nonlinear mechanical modulators. For the high-precision capacitive sensors, we present a branched finger electrodes using high-amplitude anti-phase sensing signals. We also demonstrate the potential applications of the nanoactuators and nanodetectors to high-precision positioning MEMS.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2004년도 하계학술대회
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• pp.219-222
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• 2004

정보통신설비 접지의 기본적인 방법은 각 설비에 대한 접지계통간에 아무런 접속이 되지 않는 것이다. 이것을 독립접지라고 하는데 이렇게 할 경우에 어느 한 접지체로의 이상전류 유입에 따른 대지전위 상승에 의하여 다른 접지체에 상승유도전압(rising potential)이 걸려 해당 설비에 손상을 입힐 수 있으므로 각 접지체 간에 적절한 이격거리를 확보해 주어야 한다. 그러나 설치공간상의 제약을 받게 되므로 때로는 접지계통간에 접속시켜 등전위화를 이룸으로써 이상전류 유입에 따른 영향을 배제할 수 있다. 이것을 공통접지라고 하는데 일본의 기술 영향을 받은 우리나라는 오랜 동안 독립접지 방식이 안정된 방법으로 인식해와 공통접지에 대한 우려를 가지고 있다. 그러나 최근에는 ITU-T의 접지 관련 표준화 활동에서 중요한 역할을 수행하고 일본에게 있어서도 독립접지로서 수용할 수 없는 현실적 환경 문제의 개선을 위하여 통신센터빌딩등에 적용할 수 있는 통합적인 공통접지 시스템 기술을 개발하고 있다.