• Title/Summary/Keyword: Power-Law Model

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A Study on Smart Soil Resistance Measuring Device for Safety Characterized Ground Design in Converged Information Technology (ICT 융합 환경에서의 안전 특성화 접지 설계를 위한 스마트 대지 저항 측정 기술에 관한 연구)

  • Kim, Hong-Yong;Shin, Seung-Jung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.203-209
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    • 2019
  • In this work, a new land-specific resistance measuring device (GM) and a measuring probe (Grounding Rod) are connected to the WENNER quadrant as power-line communication (PLC). In groups of two (P1,P2) probes, five to ten probes are installed in series on the ground at intervals of 1m, 2m, 4m, 8m, and 16m, respectively. If the PLC signal from the GMD is detected by the receiver of the Probe 1 (P1) for measurement, the minute voltage and current for measurement flow from the PSD (power supply) attached to the probe to the ground, and then, through the soil between P1 and P2, enters the Probe 1 (P2). The resistance value is then measured by the principle of voltage drop due to ground resistance. Measure the earth resistance every T seconds up to 1 trillion and store the measured data on the Arduino Server mounted on the main equipment. Stored measurement data can be derived from formulas by Ohm's Law and from inherent resistance (here,). Data obtained in real time will be linked to CDGES programs installed on Main PC, enabling data analysis and real-time monitoring of the ground environment on land. In addition, a three-dimensional display is possible with 3D graph support by identifying seasonal characteristics such as temperature and humidity of land (soils). The limitations of the study will require specific application measures of Test Bed for commercial access to a model that has been developed and operated experimentally.

Characteristics and Optimization of the Formula of Mashed Potatoes Using Purple-fleshed Potato (Solanum tuberosum L.) by Mixture Design (혼합물 실험계획법을 이용한 유색감자 자영(Solanum tuberosum L.) 매쉬드 포테이토 분말의 혼합비 최적화 및 매쉬드 포테이토의 특성)

  • Jung, Hwabin;Choi, Ji-il;Yoon, Won Byong
    • Food Engineering Progress
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    • v.21 no.2
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    • pp.167-173
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    • 2017
  • Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

Close Relations between Arbitration and State Court in each Procedural Stage -With an Emphasis on International Arbitration Agreement- (중재와 법원 사이의 역할분담과 절차협력 관계 -국제적 중재합의 효력에 관한 다툼과 중재합의관철 방안을 중심으로-)

  • Kim, Yong-Jin
    • Journal of Arbitration Studies
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    • v.27 no.1
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    • pp.85-106
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    • 2017
  • This article deals with the relationship between arbitration and state court in each procedural stage. As most legal systems over the world respect arbitration agreement, the relationship between arbitration and state courts puts emphasis on party autonomy and provides the independent power of arbitration agreement tribunal (Kompetenz-Kompetenz). Most institutional arbitration rules the arbitral tribunal to rule on its own jurisdiction. Modern national laws have similar provisions based on Art. 16 UNCITRAL Model Law. In this regards the author throws a question in Chapter II, whether the doctrine of Kompetenz-Kompetenz, namely the ability of the tribunal to decide upon its own jurisdiction is worth while persisting, and whether the Kompetenz-Kompetenz-agreement should be regarded as valid, with the conclusion, that this doctrine should concede to the power of state court and that Kompetenz-Kompetenz-Klausel is invalid. In Chapter III the author discusses the issue of whether the breach of an arbitration agreement could lead to the compensation of damage. Although the author stands for the procedural character of arbitration agreement, he offers a proposal that the breach of an arbitration agreement bring about the compensation of damage. The issue of anti-suit injunction is discussed also in this Chapter. He is against the approval of anti-suit injunction based on an arbitration agreement resisting the other party from pursuing a lawsuit in a foreign country.

A Study on the Development of Dynamic Positioning System for Barge Type Surface Vessels (Barge 형 수상선의 DP(Dynamic Positioning) System 개발에 관한 연구)

  • Bui, Van-Phuoc;Kim, Young-Bok
    • Journal of Power System Engineering
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    • v.16 no.2
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    • pp.66-74
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    • 2012
  • In this paper, the authors propose a new approach to control a barge type surface vessel. It is based on the Dynamic Positioning System(DPS) design. The main role of barge ship is to carry and supply the materials to the floating units and other places. To carry out this job, it should be positioned in the specified area. However sometimes the thrust systems are installed on it, and in general the rope control by mooring winch system is used. It may be difficult to compare the control performances of two types. If we consider this problem in point of usefulness, we can easily find out that the winch control system is more useful and applicable to the real field than the thrust control system except a special use. Therefore, in this paper we consider a DPS design problem which can be extended to the many application fields. The goal of this paper is twofold. First, the sliding mode controller (SMC) for positioning the our vessel is proposed. Especially, in this paper, a robust stability condition is given based on descriptor system representation. In the result, the sliding mode control law guarantees to keep the vessel in the defined area in the presence of environmental disturbances. And second, the thrust allocation problem is solved by using redistributed pseudo-inverse (RPI) algorithm to determine the thrust force and direction of each individual actuator. The proposed approach has been simulated with a supply vessel model and found work well.

A Numerical Study on Various Energy and Environmental System (II) (에너지${\cdot}$환경 제반 시스템에 관한 수치해석적 연구(II))

  • Jang D. S.;Park B. S.;Kim B. S.;Lee E. J.;Song W. Y.
    • 한국전산유체공학회:학술대회논문집
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    • 1996.05a
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    • pp.58-67
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    • 1996
  • This paper describes some computational results of various energy and environmental systems using Patankar's SIMPLE method. The specific topics handled in this study are jet bubbling reactor for flue gas desulfurization, cyclone-type afterburner for incineration, 200m tall stack for 500 MW electric power generation, double skin and heat storage systems of building energy saving for the utilization of solar heating, finally turbulent combustion systems with liquid droplet or pulverized coal particle. A control-volume based finite-difference method with the power-law scheme is employed for discretization. The pressure-velocity coupling is resolved by the use of the revised version of SIMPLE, that is, SIMPLEC. Reynolds stresses are closed using the standard $k-{\varepsilon}$ and RNG $k-{\varepsilon}$ models. Two-phase turbulent combustion of liquid drop or pulverized coal particle is modeled using locally-homogeneous, gas-phase, eddy breakup model. However simple approximate models are incorporated for the modeling of the second phase slip and retardation of ignition without consideration of any detailed particle behavior. Some important results are presented and discussed in a brief note. Especially, in order to make uniform exit flow for the jet bubbling reactor, a well-designed structure of distributor is needed. Further, the aspect ratio in the double skin system appears to be one of important factors to give rise to the visible change of the induced air flow rate. The computational tool employed in this study, in general, appears as a viable method for the design of various engineering system of interest.

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RADIO EMISSION FROM WEAK SPHERICAL SHOCKS IN THE OUTSKIRTS OF GALAXY CLUSTERS

  • Kang, Hyesung
    • Journal of The Korean Astronomical Society
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    • v.48 no.2
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    • pp.155-164
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    • 2015
  • In Kang (2015) we calculated the acceleration of cosmic-ray electrons at weak spherical shocks that are expected to form in the cluster outskirts, and estimated the diffuse synchrotron radiation emitted by those electrons. There we demonstrated that, at decelerating spherical shocks, the volume integrated spectra of both electrons and radiation deviate significantly from the test-particle power-laws predicted for constant planar shocks, because the shock compression ratio and the flux of inject electrons decrease in time. In this study, we consider spherical blast waves propagating through a constant density core surrounded by an isothermal halo with ρ ∝ r−n in order to explore how the deceleration of the shock affects the radio emission from accelerated electrons. The surface brightness profile and the volumeintegrated radio spectrum of the model shocks are calculated by assuming a ribbon-like shock surface on a spherical shell and the associated downstream region of relativistic electrons. If the postshock magnetic field strength is about 0.7 or 7 µG, at the shock age of ∼ 50 Myr, the volume-integrated radio spectrum steepens gradually with the spectral index from αinj to αinj + 0.5 over 0.1–10 GHz, where αinj is the injection index at the shock position expected from the diffusive shock acceleration theory. Such gradual steepening could explain the curved radio spectrum of the radio relic in cluster A2266, which was interpreted as a broken power-law by Trasatti et al. (2015), if the relic shock is young enough so that the break frequency is around 1 GHz.

Analytical study of bending and free vibration responses of functionally graded beams resting on elastic foundation

  • Chaabane, Lynda Amel;Bourada, Fouad;Sekkal, Mohamed;Zerouati, Sara;Zaoui, Fatima Zohra;Tounsi, Abdeldjebbar;Derras, Abdelhak;Bousahla, Abdelmoumen Anis;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.71 no.2
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    • pp.185-196
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    • 2019
  • In this investigation, study of the static and dynamic behaviors of functionally graded beams (FGB) is presented using a hyperbolic shear deformation theory (HySDT). The simply supported FG-beam is resting on the elastic foundation (Winkler-Pasternak types). The properties of the FG-beam vary according to exponential (E-FGB) and power-law (P-FGB) distributions. The governing equations are determined via Hamilton's principle and solved by using Navier's method. To show the accuracy of this model (HySDT), the current results are compared with those available in the literature. Also, various numerical results are discussed to show the influence of the variation of the volume fraction of the materials, the power index, the slenderness ratio and the effect of Winkler spring constant on the fundamental frequency, center deflection, normal and shear stress of FG-beam.

Application of nonlocal elasticity theory on the wave propagation of flexoelectric functionally graded (FG) timoshenko nano-beams considering surface effects and residual surface stress

  • Arani, Ali Ghorbanpour;Pourjamshidian, Mahmoud;Arefi, Mohammad;Arani, M.R. Ghorbanpour
    • Smart Structures and Systems
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    • v.23 no.2
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    • pp.141-153
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    • 2019
  • This research deals with wave propagation of the functionally graded (FG) nano-beams based on the nonlocal elasticity theory considering surface and flexoelectric effects. The FG nano-beam is resting in Winkler-Pasternak foundation. It is assumed that the material properties of the nano-beam changes continuously along the thickness direction according to simple power-law form. In order to include coupling of strain gradients and electrical polarizations in governing equations of motion, the nonlocal non-classical nano-beam model containg flexoelectric effect is used. Also, the effects of surface elasticity, dielectricity and piezoelectricity as well as bulk flexoelectricity are all taken into consideration. The governing equations of motion are derived using Hamilton principle based on first shear deformation beam theory (FSDBT) and also considering residual surface stresses. The analytical method is used to calculate phase velocity of wave propagation in FG nano-beam as well as cut-off frequency. After verification with validated reference, comprehensive numerical results are presented to investigate the influence of important parameters such as flexoelectric coefficients of the surface, bulk and residual surface stresses, Winkler and shear coefficients of foundation, power gradient index of FG material, and geometric dimensions on the wave propagation characteristics of FG nano-beam. The numerical results indicate that considering surface effects/flexoelectric property caused phase velocity increases/decreases in low wave number range, respectively. The influences of aforementioned parameters on the occurrence cut-off frequency point are very small.

Sensitivity analysis of input variables to establish fire damage thresholds for redundant electrical panels

  • Kim, Byeongjun;Lee, Jaiho;Shin, Weon Gyu
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.84-96
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    • 2022
  • In the worst case, a temporary ignition source (also known as transient combustibles) between two electrical panels can damage both panels. Mitigation strategies for electrical panel fires were previously developed using fire modeling and risk analysis. However, since they do not comply with deterministic fire protection requirements, it is necessary to analyze the boundary values at which combustibles may damage targets depending on various factors. In the present study, a sensitivity analysis of input variables related to the damage threshold of two electrical panels was performed for dimensionless geometry using a Fire Dynamics Simulator (FDS). A new methodology using a damage evaluation map was developed to assess the damage of the electrical panel. The input variables were the distance between the electrical panels, the vertical height of the fuel, the size of the fire, the wind speed and the wind direction. The heat flux was determined to increase as the vertical distance between the fuel and the panel decreased, and the largest heat flux was predicted when the vertical separation distance divided by one half flame length was 0.3-0.5. As the distance between the panels increases, the heat flux decreases according to the power law, and damage can be avoided when the distance between the fuel and the panel is twice the length of the panel. When the wind direction is east and south, to avoid damage to the electrical panel the distance must be increased by 1.5 times compared to no wind. The present scale model can be applied to any configuration where combustibles are located between two electrical panels, and can provide useful guidance for the design of redundant electrical panels.

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) : Constraints on the Progenitor System of a Type Ia Supernova SN 2019ein from Its Early Light Curve

  • Lim, Gu;Im, Myungshin;Kim, Dohyeong;Paek, Gregory S.H.;Choi, Changsu;Kim, Sophia;Hwang, Sungyong
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.36.1-36.1
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    • 2020
  • The progenitor of Type Ia supernovae (SNe Ia) is mainly believed to be a carbon/oxygen white dwarf (WD) with non-degenerate (single degenerate) or another WD companion (double degenerate). However, there is little observational evidence of their progenitor system. Recent studies suggest that shock-breakout cooling emission after the explosion can constrain the size of the progenitor system. To do so, we obtained a optical/Near-IR light curve of SN 2019ein, a normal but slightly sub-luminous type Ia supernova, from the very early phase using our high-cadence observation of Intensive Monitoring Survey of Nearby Galaxies (IMSNG). Assuming the expanding fireball model, the simple power-law fitting of the early part of the light curve gives power indices of 1.91 (B) and 2.09 (R) implying radioactive decay of 56Ni is the dominant energy source. By comparison with the expected light curve of the cooling emission, the early observation provides us an upper limit of the companion size of R∗≤1R⊙. This result suggests that we can exclude a large companion such as red giants, which is consistent with the previous study.

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