• Title/Summary/Keyword: flow sheet

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Cash Flow Statement Preparation Using Accounts Reconciliation Method for IACF (계정조정 방식에 의한 산학협력단 현금흐름표 작성)

  • Kang, Jinhwa;Ahn, Jaekyoung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.2
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    • pp.47-55
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    • 2018
  • The Korean Ministry of Education (MOE) required cash flow statements, instead of fund statements, as a component of the financial statements of the Industry-Academic Cooperation Foundations (IACF) when it revised IACF accounting rules in 2012. While the fund statements were aligned its accounts to the operating statements' accounts level, the newly adopted cash flow statements' accounts retreated to two levels higher than those of the operating statements. It may be resulted from the consideration that IACFs' burden of preparing cash flow statements especially in direct method. To help IACFs prepare the cash flow statements, MOE's guidance on IACF accounting rules introduced cash flow statement preparation method and presented a practical example, but it did not check whether the accounts of the cash flow statement were reconciled to the accounts of corresponding balance sheet and operating statement. That means that the guidance still lacks how to assure it was accurately prepared. Our study proposed cash flow statement preparation using reconciliation method which reconciles cash flow statement accounts' amounts to balance sheet and operating statement accounts' amounts with integrity checking and also provided a practical example by using the same case in MOE's guidance on IACF accounting rules to help IACF accounting personnel to prepare a cash flow statement efficiently.

NUMERICAL METHODS FOR CAVITATING FLOW

  • SHIN Byeong Rog
    • 한국전산유체공학회:학술대회논문집
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    • 2001.10a
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    • pp.1-9
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    • 2001
  • In this paper, some numerical methods recently developed for gas-liquid two-phase flows are reviewed. And then, a preconditioning method to solve cavitating flow by the author is introduced. This method employs a finite-difference Runge-Kutta method combined with MUSCL TVD scheme, and a homogeneous equilibrium cavitation model. So that it permits to treat simply the whole gas-liquid two-phase flow field including wave propagation, large density changes and incompressible flow characteristic at low Mach number. Finally, numerical results such as detailed observations of the unsteady cavity flows, a sheet cavitation break-off phenomena and some data related to performance characteristics of hydrofoils are shown.

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A method of determining flow stress and friction factor using an inverse analaysis in ring compression test (링압축시험에서 역해석을 이용한 유동응력과 마찰상수 결정법)

  • Choi, Y.;Kim, H.K.;Cho, H.Y.;Kim, B.M.;Choi, J.C.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.3
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    • pp.483-492
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    • 1998
  • An inverse analysis been applied to obtain the flow stress of the material. In this method, a ring-shaped specimen is compressed between two flat tools. This procedure employs, as the object function of inverse analysis, the balance of measured loads and reaction forces calculated by using rigid-plastic finite element method. The balance is explicit scalar function of flow stress which is a function of some unknown constants. For minimizing the balance, Newton-Raphon scheme is used. The friction factor, m, between flat tools and the specimen is determined by using friction area-divided method. The proposed method allows an accurate identification by avoiding the usual assumptions made in order to convert experimental measures into stress-strain relation. In this paper, the proposed method is numerically tested. A commercial pure aluminum was selected, as an example, to apply the method and the results are compared with stress-strain relation obtained by experiments.

Design of Non-Contact Pick-Up Head for Carrying Large Flat Sheets (대평판 이송을 위한 비접촉 헤드 설계)

  • Kim, Joon Hyun;Kim, Young Geul;Ahn, Sung Wook;Kim, Young Sung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.6
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    • pp.937-944
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    • 2013
  • This paper describes an improved model that can be used for configuring a non-contact pneumatic head to handle a large sheet of glass. The cylindrical head model is of a large size (70 mm). It operates on vortex flow, which can simultaneously generate suction and repulsion over the flat object's surface. The head allows for the minimal non-contact lifting of objects weighing over 3N by using reference conditions (working pressure and head dimensions). Additionally, a functional flow-guide is applied for inducing a developing tangential vortex flow to increase suction and repulsion to the reference head. The cylindrical flow-guide is associated with relatively low tangential velocity. The improved model generates greater lifting force than the reference model, as verified experimentally.

Earthward Flow Bursts in the Magnetotail Driven by Solar Wind Pressure Impulse

  • Kim, Khan-Hyuk;Kwak, Young-Sil;Lee, Jae-Jin;Hwang, Jung-A
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.375-382
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    • 2008
  • On August 31, 2001, ${\sim}$ 1705 - 1718 UT, Cluster was located near the midnight magnetotail, GSE (x, y, z) ${\sim}$ (-19, - 2,2) RE, and observed fast earthward flow bursts in the vicinity of the neutral sheet. They occurred while the tail magnetic field suddenly increased. Using simultaneous measurements in the solar wind, at geosynchronous orbit, and on the ground, it is confirmed that tail magnetic field enhancement is due to an increased solar wind pressure. In the neutral sheet region, strongly enhanced earthward flow bursts perpendicular to the local magnetic field $(V_{{\perp}x})$ were observed. Auroral brightenings localized in the pre-midnight sector (${\sim}$ 2200 - 2400 MLT) occurred during the interval of the $V_{{\perp}x}$ enhancements. The $V_{{\perp}x}$ bursts started ${\sim}$ 2 minutes before the onset of auroral brightenings. Our observations suggest that the earthward flow bursts are associated with tail reconnection directly driven by a solar wind pressure impulse and that $V_{{\perp}x}$ caused localized auroral brightenings.

Composition and interface quality control of AlGaN/GaN heterostructure and their 2DEG transport properties

  • Kee, Bong;Kim, H.J.;Na, H.S.;Kwon, S.Y.;Lim, S.K.;Yoon, Eui-Joon
    • Journal of Korean Vacuum Science & Technology
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    • v.4 no.3
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    • pp.81-85
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    • 2000
  • The effects of $NH_3$ flow rate and reactor pressure on Al composition and the interface of AlGaN/GaN heterostructure were studied. Equilibrium partial pressure of Ga and Al over AiGaN alloy was calculated as a function of growth pressure, $NH_3$flow rate and temperature. It was found equilbrium vapor pressure of Al is significantly lower than that of Ga, thus, the alloy composition mainly controlled by Ga partial pressure. We believe that more decomposition of Ga occur at lower $NH_3$ flow rate and higher growth pressure leads to preferred Al incorporation into AlGaN. The alloy composition gradient became larger at AlGaN/GaN heterointerface at higher reactor pressures, higher Al composition and low $NH_3$ flow rate. This composition gradient lowered sheet carrier concentration and electron mobility as well. We obtained an AlGaN/GaN heterostructure with sheet carrier density of ${\sim}2{\times}10^{13}cm^{-2}$ and mobility of 1250 and 5000 $cm^2$/Vs at 300 K and 100 K, respectively.

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Non-Contact Pick-up System for Turning Large Flexible Thin Sheets (대형 유연박판 회전이송용 비접촉 파지시스템 설계)

  • Kim, Joon Hyun;Ahn, Sung Wook;Lee, Se Jin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.5
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    • pp.435-442
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    • 2014
  • This paper describes an improved design model that can be used to configure a non-contact pneumatic device to turn a large sheet at the in-line system. For rotational moving in the conveyor system, the conventional method is to turn the system itself. The improved non-contact pick-up system mainly uses 8 pairs of L-shaped latches and 12 swirl type heads. It is positioned above the upward air flow table. This system performs the non-contact gripping and side-edge contact support in the vertical and rotational directions to hold the self-weight of a large flat sheet. A non-contact air head can exert a sufficient gripping ability at 4N lower than the standard working pressure. The side latches support 60% of the lifting force required. Through structural and flow analysis, the working conditions were simultaneously considered in accordance with the deflection and flatness of the glass.

A New Yield Function for Voided Materials (보이드 재료에 대한 새로운 항복함수의 제안)

  • 김성태
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.13-16
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    • 2000
  • In this paper the authors proposed a new anisotropic yield criterion for porous ductile materials. By using the proposed yield criterion and its flow rules a damage evolution of anisotropic sheet under biaxial tensile loading is investigated. A comparison of yield locus and damage evolution between the proposed yield criterion and experiments are carried out. the results are in good agreement.

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Development of 3D Sheet Metal Forming Analysis Program by explicit finite element method (외연적 탄소성 유한요소법에 의한 3차원 박판금속 성형해석 프로그램 개발)

  • 정완진
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.03a
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    • pp.217-221
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    • 1997
  • In this study, 3D sheet metal forming analysis program is developed by explicit finite element method. In this program, analysis flow just follows the real engineering process to provide the user intuitive understanding and smooth contact alorithm improves the accuracy of stress prediction. The capability of this program are demonstrated by various examples.

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Flexural Behavior of FRC with Composite Waterproof Sheet (복합방수시트로 보강된 섬유보강콘크리트 휨거동)

  • Kim, Byoungil
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.215-216
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    • 2023
  • Leakage in the structure due to the irregular flow of groundwater in the underground structure penetrates into internal spaces such as underground parking lots and basement through underground walls, which is expensive in terms of maintenance of the building. In this study, various composite waterproofing methods installed on the outer walls of underground structures were selected to evaluate the structural performance of composite specimens due to bending behavior through experiments and analysis on bending test behavior on concrete attachment surfaces.

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