• Title/Summary/Keyword: Energy shaping

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Four Representative Applications of the Energy Shaping Method for Controlled Lagrangian Systems

  • Ng, Wai Man;Chang, Dong Eui;Song, Seong-Ho
    • Journal of Electrical Engineering and Technology
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    • v.8 no.6
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    • pp.1579-1589
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    • 2013
  • We provide a step-by-step, easy-to-follow procedure for the method of controlled Lagrangian systems. We apply this procedure to solve the energy shaping problem for four benchmark examples: the inertial wheel pendulum, an inverted pendulum on a cart, the system of ball and beam and the Furuta pendulum.

Applying Workload Shaping Toward Green Cloud Computing

  • Kim, Woongsup
    • International journal of advanced smart convergence
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    • v.1 no.2
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    • pp.12-15
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    • 2012
  • Energy costs for operating and cooling computing resources in Cloud infrastructure have increased significantly up to the point where they would surpass the hardware purchasing costs. Thus, reducing the energy consumption can save a significant amount of management cost. One of major approach is removing hardware over-provisioning. In this paper, we propose a technique that facilitates power saving through reducing resource over provisioning based on virtualization technology. To this end, we use dynamic workload shaping to reschedule and redistribute job requests considering overall power consumption. In this paper, we present our approach to shape workloads dynamically and distribute them on virtual machines and physical machines through virtualization technology. We generated synthetic workload data and evaluated it in simulating and real implementation. Our simulated results demonstrate our approach outperforms to when not using no workload shaping methodology.

A study on torque shaping method for slewing and vibration suppression of flexible structures (유연우주비행체의 선회 및 진동억제를 위한 Torque Shaping 기법에 관한 연구)

  • 문종윤;석진영;김유단
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1087-1090
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    • 1996
  • The objective of this paper is to present a new input torque shaping method for slewing and vibration suppression of flexible structure based on Fourier series expansion. Vibration energy of the structure with shaped control input is investigated with respect to the shaping parameter of the reference torque, maneuver time and the number of trigonometric functions to be included in the series. Analytic expressions of the performance indices and their derivatives are derived in the modal coordinates. Numerical results show the effectiveness of the proposed approach to design the open-loop control law that modifies the shape of input torque for simultaneous slewing and vibration suppression.

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Control of Intensity Distribution Profile of Laser Beam using Beam Shaping Mask with Random Array Slits (빔셰이퍼 마스크를 이용한 레이저 빔의 강도 분포 제어)

  • Oh, Jae-Yong;Park, Deog-Su;Shin, Bo-Sung
    • Laser Solutions
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    • v.15 no.2
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    • pp.11-14
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    • 2012
  • In this paper, we have made a proposal concerning the beam shaping mask(BSM) using random-array slits to control intensity distribution profile of laser beam and demonstrated its proprieties experimentally. When a lot of slits are set out irregularly, diffraction patterns of light does not appear but granularity patterns as a bundle of fibers appear. Intensity distribution profile is controlled by densities distribution of circular slits arrayed randomly because the number of slits and its area means amount of light energy through BSM. Namely as the number of slits in high intensity area is increased and that in low intensity area decreased, amount of light energy is same over all local parts. So gaussian intensity distribution could be changed to flat-top.

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Comparison of Performance of Brushless DC Drives under Direct Torque Control and PWM Current Control

  • Zhu Z. Q.;Liu Yong;Howe David
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.5B no.4
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    • pp.337-342
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    • 2005
  • Direct torque control (DTC) was originally developed for induction machine drives, and, more recently has been applied to permanent magnet brushless AC (BLAC) drives. In this paper, the performance of DTC controlled brushless DC (BLDC) drives is compared with that of PWM current controlled BLDC drives, both with and without current shaping. Both simulation and experimental results are presented, as well as the analysis of the resulting torque waveforms. It is shown that, in addition to exhibiting a fast torque response, a DTC controlled BLDC drive has a significantly lower low-frequency torque ripple than the PWM current controlled BLDC drive without current shaping, and that it is easier to implement than PWM current control with current shaping.

Robust LQ control of magnetically levitation systems with a combined lift and guidance using loop-shaping techniques (루프형성 기법을 이용한 편심배치방식 자기부상 시스템의 강인 LQ 제어)

  • 박전수;김종식
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.747-753
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    • 1992
  • The modeling and control design schemes are developed for maglev systems with a combined lift and guidance. First, bond graph techniques are applied for modeling these multi-energy domain systems more logically and systematically. And the stability loop via pole placement and the performance loop via loop-shaping LQ control are designed. The suggested controller satisfies the required characteristics of stability and performance simultaneously. Finally, the robustness of the synthesized maglev control system is evaluated for the variations of air gap and vehicle mass through computer simulation.

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Torque shaping for near-minimum-time optimal slewing of 3-axis spacecraft (3축 위성체의 준최소시간 선회기동을 위한 입력형상최적화)

  • 김기석;김희섭;김유단
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1330-1333
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    • 1997
  • In this paper, the optimal torque shaping is obtained for 3-axis rotation of a spacecraft. The true optimal 3-axis rotation of rigid spaeraft is first investigated via parameter optimization method with prescribed switching times. Input torque shape of the troque generating device mounted on the central hub is optimized using fourier Series expansion so that the spacecraft may slew while minimizing the vibration energy of flexible modes. Numerical results show that proposed method suggests a reference trahectory for open-loop control, and also verify that it can minimize the vibratory modes of the spacecraft during/after the rest-to-rest maneuver.

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Analysis of values-beliefs-norms of decommissioned nuclear power plant reestablishment acceptance in developing countries: a perspective from the Philippines

  • Leo Miguel V. Tolentino;Ardvin Kester S. Ong;Josephine D. German
    • Nuclear Engineering and Technology
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    • v.56 no.8
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    • pp.3224-3235
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    • 2024
  • Amid the ongoing discourse on clean energy solutions, the reopening of decommissioned plants, such as the Bataan Nuclear Power Plant (BNPP) in the Philippines has become a focal point in the country. This study delved into the complex web of factors influencing public acceptance of BNPP, employing the values-beliefs-norms theory. By utilizing partial-least square structural equation modeling, the research unravelled the intricate relationships among biospheric values, altruistic values, egoistic values, ecological worldview, awareness of consequences, personal norm, social norm, and the broader acceptance of BNPP establishment. With 434 respondents participating in a self-administered online survey, the study identified key correlations. Emphasizing the collaborative impact on decision-making processes by social and personal norms, the study also highlighted the role of ecological values in shaping awareness. The foundational impact of values on ecological worldviews was explored, shedding light on public attitudes toward nuclear energy. This research offers actionable insights for policymakers, advocating for targeted communication strategies and public engagement initiatives to navigate barriers and promote informed decision-making in the dynamic landscape of nuclear energy development. The study contributes to the global conversation on sustainable energy strategies, emphasizing the pivotal role of public perception in shaping the trajectory of nuclear power.

Combined X-ray CT/SPECT System with a Common CZT Detector (CZT검출기를 이용한 CT/SPECT 조합영상시스템)

  • 권수일
    • Progress in Medical Physics
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    • v.13 no.4
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    • pp.229-233
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    • 2002
  • We have tested a combined CT/SPECT system with a single CZT detector for x-ray and gamma-ray medical imaging. The size of detector is 10$\times$10$\times$5 ㎣, and the anodes are pixellated as a 4$\times$4 array with a pixel dimension of $1.5\times$1.5 $\textrm{mm}^2$. The cathode was coated with a continuous Au-plated. We have characterized the system performance by scanning a radiographic resolution phantom and the Hoffman Brain phantom. Pulse counting electronics with very short shaping time (50 ㎱) are used to satisfy high photon rates in x-ray imaging, and response linearity up to 3$\times$10$^{5}$ counts per second per detector element is achieved. Energy resolution of 10.4% and 5.3% FWHM at Tc-99m 140 keV peak are obtained for the 50 ㎱ and 2 $mutextrm{s}$ shaping times, respectively. The spatial resolutions of CT and SPECT are about 1mm and 9mm, respectively. Photopeak efficiency of detector systems are 41.0% for 50㎱ and 72.5% for 2 $mutextrm{s}$ shaping time.

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A Study on the Effect of Field Shaping on Dose Distribution of Electron Beams (전자선의 선량분포에 있어서 Field Shaping의 효과에 관한 연구)

  • Kang, Wee-Saing;Cho, Moon-June
    • Radiation Oncology Journal
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    • v.4 no.2
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    • pp.165-172
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    • 1986
  • In electron therapy, lead cutout or low-melting alloy block is used for shaping the field. Material for shaping electron field affects the output factor as wet 1 as the collimation system. The authors measured the output factors of electron beams for shaped fields from Clinac-18 using ionization chamber of Farmer type in polystyrene phantom. They analyzed the parameters that affect the output factors. The output factors of electron beams depend on the incident energy, collimation system and size of shaped field. For shaped field the variation of output factor for the field size (A/P) has appearence of a smooth curve for all energy and all applicator collimator combination. The output factors for open field deviate from the curves for shaped fields. An output factor for a given field can be calculated by equivalent field method such as A/P method, if a combination of applicator and collimator is fixed.

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