• Title/Summary/Keyword: Dynamic expansion

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Effect of Base Paper Properties on Warp of Corrugated Board (골판지의 와프 현상발생에 대한 원지 특성의 영향)

  • Lee Jin-Ho;Park Jong-Moon;Lee Sang-Hyun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.1 s.113
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    • pp.54-61
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    • 2006
  • Basically corrugated board is composed of three layers of different basis weight and stock composition. Warp is well-known for one of the most important problems of corrugated board production. Warp is caused by difference of hygro-expansibility of linears between top and bottom. This research was performed to evaluate the effect of paper properties on the warp of corrugated board. To evaluate warp, dynamic expansion properties of paper was tested using DPM(dynamic penetration measuring system). The effects of sizing, stock composition and wet-pressing on dynamic expansion properties were also evaluated. Commercial base papers showed different dynamic expansion property depending on stock composition and papermaking operation. Sizing treatment decreased and wet-pressing increased the amount of dynamic expansion. To reduce warp of corrugated board, management of dynamic expansion of base papers should be controlled by manipulating moisture, heat and tension, using a variety of adjustments available on the corrugator.

A Case Study on the Effect of Damaged Expansion Joint for Safety Assessment of Highway Bridges

  • Kim, Kwang-Il;Chai, Won-Kyu;Lee, Myeong-Gu;Son, Young-Hyun
    • International Journal of Safety
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    • v.9 no.2
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    • pp.16-21
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    • 2010
  • In this study, the variations of transformed impact factors and load carrying capacity of highway bridges measured from the state of expansion joint are evaluated. the field loading tests were performed on the highway bridge with damaged expansion joint to investigate the variation of the load carrying capacity. From the field loading tests in case that damaged expansion joint exist or do not exist, the static displacements and dynamic displacements were measured, and TIF were calculated, respectively. dynamic test is performed in order to estimate dynamic displacement and TIF according to the level of damage of expansion joint. From the results of TIF, the load carrying capacity of highway bridges with damaged expansion joint were estimated.

A Shortest Path Dynamic Programming for Expansion Sequencing Problems

  • Kim, Sheung-K.
    • Journal of Korean Institute of Industrial Engineers
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    • v.12 no.1
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    • pp.81-94
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    • 1986
  • A shortest path dynamic programming formulation is proposed and attemped to solve an uncapacitated expansion sequencing problem. It is also compared with the Extended Binary State Space approach with total capacity. Difficulties and merits associated with the formulation are discussed. The shortest path dynamic programming lacks the separability condition and an optimal solution is not guaranteed. However it has other merits and seems to be the practical solution procedure for the expansion sequencing problem in a sense that it finds near optimal solution with less state evaluations.

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Dynamic Analysis of Expansion in Perlite (퍼라이트팽창의 동적해석)

  • Hahm, Yeong-Min
    • Applied Chemistry for Engineering
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    • v.23 no.2
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    • pp.143-147
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    • 2012
  • Since the expansion of perlite occurs in a few second in high temperature, it is difficult to identify an expansion phenomenon through experiments. In order to explain this phenomenon, a numerical study has been carried out by setting a model that water vapour diffuses to a tiny bubble existing in perlite melts and then makes the bubble grow and perlite expand. When the bubble grew and the perlite expanded due to the diffusion of water vapour, the dynamic temperature of perlite decreased. Meanwhile, the dynamic pressure of bubble increased at the beginning as water vapour diffuses in melts, but rather decreased after a rapid expansion of bubble.

Fragility curves for the typical multi-span simply supported bridges in northern Pakistan

  • Waseem, Muhammad;Spacone, Enrico
    • Structural Engineering and Mechanics
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    • v.64 no.2
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    • pp.213-223
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    • 2017
  • Bridges are lifeline and integral components of transportation system that are susceptible to seismic actions, their vulnerability assessment is essential for seismic risk assessment and mitigation. The vulnerability assessment of bridges common in Pakistan is very important as it is seismically very active region and the available code for the seismic design of bridges is obsolete. This research presents seismic vulnerability assessment of three real case simply supported multi-span reinforced concrete bridges commonly found in northern Pakistan, having one, two and three bents with circular piers. The vulnerability assessment is carried through the non-linear dynamic time history analyses for the derivation of fragility curves. Finite element based numerical models of the bridges were developed in MIDAS CIVIL (2015) and analyzed through with non-linear dynamic and incremental dynamic analyses, using a suite of bridge-specific natural spectrum compatible ground motion records. Seismic responses of shear key, bearing pad, expansion joint and pier components of each bridges were recorded during analysis and retrieved for performance based analysis. Fragility curves were developed for the bearing pads, shear key, expansion joint and pier of the bridges that first reach ultimate limit state. Dynamic analysis and the derived fragility curves show that ultimate limit state of bearing pads, shear keys and expansion joints of the bridges exceed first, followed by the piers ultimate limit state for all the three bridges. Mean collapse capacities computed for all the components indicated that bearing pads, expansion joints, and shear keys exceed the ultimate limit state at lowest seismic intensities.

Capacity Expansion Planning Model of Private Distribution Center Under Usability of Public Distribution Center (영업용 물류센터 사용하에서 자가 물류센터의 크기 확장계획 모형)

  • Chang, Suk-Hwa
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.1
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    • pp.71-79
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    • 2010
  • This paper addresses capacity expansion planning model of distribution center under usability of public distribution center. For discrete and finite time periods, demands for distribution center increase dynamically. The capacity expansion planning is to determine the capacity expansion size of private distribution center and usage size of public distribution center for each period through the time periods. The capacity expansion of private distribution center or lease usage of public distribution center must be done to satisfy demand increase for distribution center. The costs are capacity expansion cost and excess capacity holding cost of private distribution center, lease usage cost of public distribution center. Capacity expansion planning of minimizing the total costs is mathematically modelled. The properties of optimal solution are characterized and a dynamic programming algorithm is developed. A numerical example is shown to explain the problem.

Illuminance Dynamic Range Expansion using Gamma & Multi-Point Knee for Smart Phone Camera (감마 및 다중 포인터 니를 이용한 스마트폰 카메라의 광 다이나믹 영역 확장)

  • Choi, Duk-Kyu;Han, Chan-Ho
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.1
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    • pp.43-50
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    • 2013
  • The narrow dynamic range of most smart phone cameras is severely limited. It usually is narrower than the dynamic range of most scenes. So we proposes a illuminance dynamic range expansion using multi-point knee for smart phone camera. Such as logarithmic functions the proposed method compress the image sensor output signal. Additionally, the proposed method was merged into the gamma that is essential circuit for any cameras. To justifying multi-point knee effectiveness, we configure the control and quality evaluation system for smart phone camera module. Experimental results show that the lost information by cut off and saturated affectively reconstructed in darker and in brighter areas. Finally this methods have advantage to implement without any changing hardware for conventional smart phones.

Development of Uncertainty Evaluation Model for Vacuum Measurement Standards (진공측정표준의 불확도 평가모델 개발)

  • Hong, S.S.;Lim, J.Y.;Shin, Y.H.
    • Journal of the Korean Vacuum Society
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    • v.20 no.5
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    • pp.313-321
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    • 2011
  • The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM), a static volume expansion system (SVES), and an orifice-type dynamic expansion system (ODES). For each system explict measurement model equations with multiple variables are respectively given. According to ISO standards, all these system variables errors were used to calculate the expanded uncertainty (U).

Influence of Thermal Expansion on Eccentricity and Critical Speed in Dry Submersible Induction Motors

  • Lv, Qiang;Bao, Xiaohua;He, Yigang
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.106-113
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    • 2014
  • Rotor eccentricity is one of the major factors that directly influence the security of horizontal electrical machines, and the critical speed of the shaft has a close relationship with vibration. This paper deals with the influence of thermal expansion on the rotor eccentricity and critical speed in large dry submersible motors. The dynamic eccentricity (where the rotor is still turning around the stator bore centre but not its own centre) and critical speed of a three-phase squirrel-cage submersible induction motor are calculated via hybrid analytical/finite element method. Then the influence of thermal expansion is investigated by simulation. It is predicted from the study that the thermal expansion of the rotor and stator gives rise to a significant air-gap length decrement and an inconspicuous slower critical speed. The results show that the thermal expansion should be considered as an impact factor when designing the air gap length.

Expansion of Measured Static and Dynamic Data as Basic Information for Damage Detection

  • Eun, Hee-Chang;Lee, Min-Su;Chung, Chang-Yong;Kwak, No-Hyun
    • Architectural research
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    • v.10 no.2
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    • pp.21-26
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    • 2008
  • The number of measured degrees of freedom for detecting the damage of any structures is usually less than the number of model degrees of freedom. It is necessary to expand the measured data to full set of model degrees of freedom for updating modal data. This study presents the expansion methods to estimate all static displacements and dynamic modal data of finite element model from the measured data. The static and dynamic methods are derived by minimizing the variation of the potential energy and the Gauss's function, respectively. The applications illustrate the validity of the proposed methods. It is observed that the numerical results obtained by the static approach correspond with the Guyan condensation method and the derived static and dynamic approaches provide the fundamental idea for damage detection.