• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2590-2592
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• 2000

본 논문에서는 TV 브라운관 유리용해로의 온도 제어를 위한 고전 고급 제어 (Conventional Advanced Control) 알고리듬을 제시한다. 용해로의 특성에 맞도록 중요한 입출력 변수를 선정한 후, 공정 실험을 통하여 얻어진 데이터를 바탕으로 입출력 변수들간의 초보적인 FOPDT (First Order Plus Dead Time) 모델들의 조합으로 용해로를 모델링하였다. 수립된 모델을 바탕으로 주요 입출력을 PI (Proportional - Integral) 형태의 cascade 및 단일 궤환 루프(Single feedback loop)들의 조합으로 제어기를 구성하였다. 제시된 알고리듬은 기존 용해로에 설치되어 있는 DCS를 이용하여 구현되었고, 일 150톤 생산 규모의 용해로에 성공적으로 실적용되었다.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.238.1-238.1
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• 2003

Tissue Factor (TF), a principal initiator of the veterbrate coagulation cascade is known to to induced in endothelial cells, monocytes and macrophages by inflammetry stimuli and in many pathological conditions. Through our synthetic efforts to develop new TF inhibitors, seventeen N-C-18 alkenyl group (9-octadecenyl or 9,12-octadecadienyl) substituted aminoalcohols (2-aminoethanol, 1-amino-2-propanol and 3-amino-1-propanol) were prepared and their in vitro TF inhibitory activities were examined. (omitted)

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1447-1448
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• 2011

초저온 액화 공정 플랜트의 정상 운전시 제어 로직을 사전에 점검할 수 있는 테스트 플랫폼을 개발하였다. 초저온 액화 공정 플랜트상의 주요 제어 대상 포안트 17 개를 선정하여 PID 및 cascade 제어 알고리즘을 구현하였으며 이를 시뮬레이터에 연결하여 제어 로직 계산 결과를 테스트하였다. 시뮬레이터에서는 제어시스템의 제어 로직에 대한 동적 반응 특성을 계산하여 제시함으로써 제어시스템의 제어 로직을 사전에 분석, 점검할 수 있도록 역할을 수행한다.

• The Journal of the Acoustical Society of Korea
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• v.39 no.6
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• pp.515-523
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• 2020

This study aims to improve the flow and noise performances of an axial-flow fan for cooling the machine room in a refrigerator by using airfoil-cascade analysis and surface ridge shape. First, the experimental evaluations using a fan performance tester and an anechoic chamber are performed to analyze the flow and noise performances of the existing fan system. Then, the corresponding flow and noise performances are numerically assessed using the Computational Fluid Dynamics (CFD) techniques and the Ffowcs-Williams and Hawkings (FW-H) equation, and the validity of numerical results are confirmed through their comparisons with the experimental results. The analysis for the flow of a cascade of airfoils constructed from the existing fan blades is performed, and the pitch angles for the maximum lift-to-drag ratio are determined. The improved flow performance of the new fan applied with the optimum pitch angles is confirmed. Then, the fan blades with surface ridges on their pressure sides are devised, and the reduction of aerodynamic noise of the ridged fan is numerically confirmed. Finally, the prototype of the final fan model is manufactured, and improvements in the flow and noise performances of the prototype are experimentally confirmed.

• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.415-431
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• 2022

Secondary flows have a huge impact on losses generation in modern low pressure gas turbines (LPTs). At design point, the interaction of the blade profile with the end-wall boundary layer is responsible for up to 40% of total losses. Therefore, predicting accurately the end-wall flow field in a LPT is extremely important in the industrial design phase. Since the inlet boundary layer profile is one of the factors which most affects the evolution of secondary flows, the first main objective of the present work is to investigate the impact of two different inlet conditions on the end-wall flow field of the T106A, a well known LPT cascade. The first condition, labeled in the paper as C1, is represented by uniform conditions at the inlet plane and the second, C2, by a flow characterized by a defined inlet boundary layer profile. The code used for the simulations is based on the Discontinuous Galerkin (DG) formulation and solves the Reynolds-averaged Navier-Stokes (RANS) equations coupled with the Spalart Allmaras turbulence model. Secondly, this work aims at estimating the influence of viscosity and turbulence on the T106A end-wall flow field. In order to do so, RANS results are compared with those obtained from an inviscid simulation with a prescribed inlet total pressure profile, which mimics a boundary layer. A comparison between C1 and C2 results highlights an influence of secondary flows on the flow field up to a significant distance from the end-wall. In particular, the C2 end-wall flow field appears to be characterized by greater over turning and under turning angles and higher total pressure losses. Furthermore, the C2 simulated flow field shows good agreement with experimental and numerical data available in literature. The C2 and inviscid Euler computed flow fields, although globally comparable, present evident differences. The cascade passage simulated with inviscid flow is mainly dominated by a single large and homogeneous vortex structure, less stretched in the spanwise direction and closer to the end-wall than vortical structures computed by compressible flow simulation. It is reasonable, then, asserting that for the chosen test case a great part of the secondary flows details is strongly dependent on viscous phenomena and turbulence.

• Development and Reproduction
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• v.6 no.1
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• pp.1-6
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• 2002

To elucidate the mechanism underlying the embryotropic effect of extracellular matrix(ECM) on the preimplantation development of mammalian embryos, the involvement of mitogen-activated protein kinase(MAPK) downstream the integrin signaling was examined in mouse blastocysts. Blastocysts were cultured in the presence of growth factor-reduced(GFR) Matrigel(0.5％, v/v). MAPK activity was measured by in vitro phosphorylation of myelin basic protein by the Erk1/2 antibody immunoprecipitates of embryonic extract following the Matrigei treatment. MAPK activity of the early blastocysts rapidly increased within 10 min fo1lowing the Matrigel treatment. When the embryos were cultured for 12 h in the presence of Matrigel, the MAPK activity was significantly higher than that ot the control embryos. PD098059, a MAPK kinase(MEK) inhibitor, attenuated the effect of Matrigel on the change in MAPK activity. Taken together, it suggested that the embryotropic effect of ECM proteins might be mediated by the activation of MAPK cascade.

• The Journal of Korea Robotics Society
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• v.13 no.3
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• pp.157-163
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• 2018

This paper deals with the development and application of control algorithms for series elastic relief robots for rescue operations in harsh environment like disasters or battlefield. The joint controller applied in this paper has a cascade structure combining inner loop for torque control and outer loop for position control. The torque loop contains feedforward and feedback controller and disturbance observer for independent, decentralized joint control. The effect of the elastic component and motor dynamics are treated as the nonlinear disturbance and compensated with the disturbance observer of torque controller. For the collision detection, Band Designed Disturbance Observer is configured to recognize/respond to external disturbance robustly in the continuously changing environment. The controller is applied to a 7-dof series elastic manipulator to evaluate the torque tracking and collision detection/response performance.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.446-450
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• 2004

The amount of electric energy used in a vehicle will be increased continuously. The increment of electric power demand causes interest on new higher power system such as 42V Power Net. Furthermore, the necessity for development of energy storage device is highlighted recently. Bidirectional nm Converter is one of the important parts in 42V power system. Therefore, this paper proposes bidirectional Cascade Buck-Boost DC/DC Converter which can satisfies required specifications in 42V power system The operation principle is described along with simple control method, and experimental results on a 500W prototype are provided.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.109-120
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• 2008

An innovative method of changing a centrifugal low specific speed pump performance and pressure fluctuation by applying outlet flaps to impeller exit has been investigated. The outlet blade edge section corresponds to the trailing edge of wing on the circular-cascade, which dominates the pump performance and pressure fluctuation. Computational fluid dynamics (CFD) analysis of the entire impeller and volute casing and an experimental investigation are conducted. The pressure fluctuation and the vibration of the shaft are measured simultaneously. Kurtosis is applied as a dimensionless parameter with which the unevenness of velocity distribution at impeller outlet is indicated. The influence of the flaps on the pressure fluctuation is explained by the kurtosis. This paper presents a theoretical method of predicting the pump performance related to the attachment of a flap at impeller outlet.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4041-4047
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• 2013

Cancer vaccine development is in the process of becoming reality in future, due to successful phase II/III clinical trials. However, there are still problems due to the specificity of tumor antigens and weakness of tumor associated antigens in eliciting an effective immune response. Computational models to assess the vaccine efficacy have helped to improve and understand what is necessary for personalized treatment. Further research is needed to elucidate the mechanisms of activation of antigen specific cytotoxic T lymphocytes, decreased TREG number functionality and antigen cascade, so that overall improvement in vaccine efficacy and disease free survival can be attained. T cell epitomic based in sillico approaches might be very effective for the design and development of novel cancer vaccines.