• Title/Summary/Keyword: mixed formulation

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CONVERGENCE ANALYSIS OF PARALLEL S-ITERATION PROCESS FOR A SYSTEM OF VARIATIONAL INEQUALITIES USING ALTERING POINTS

  • JUNG, CHAHN YONG;KUMAR, SATYENDRA;KANG, SHIN MIN
    • Journal of applied mathematics & informatics
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    • v.36 no.5_6
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    • pp.381-396
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    • 2018
  • In this paper we have considered a system of mixed generalized variational inequality problems defined on two different domains in a Hilbert space. It has been shown that the solution of a system of mixed generalized variational inequality problems is equivalent to altering point formulation of some mappings. A new parallel S-iteration type process has been considered which converges strongly to the solution of a system of mixed generalized variational inequality problems.

On the performance of heat absorption/generation and thermal stratification in mixed convective flow of an Oldroyd-B fluid

  • Hayat, Tasawar;Khan, Muhammad Ijaz;Waqas, Muhammad;Alsaedi, Ahmed
    • Nuclear Engineering and Technology
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    • v.49 no.8
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    • pp.1645-1653
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    • 2017
  • This investigation explores the thermally stratified stretchable flow of an Oldroyd-B material bounded by a linear stretched surface. Heat transfer characteristics are addressed through thermal stratification and heat generation/absorption. Formulation is arranged for mixed convection. Application of suitable transformations provides ordinary differential systems through partial differential systems. The homotopy concept is adopted for the solution of nonlinear differential systems. The influence of several arising variables on velocity and temperature is addressed. Besides this, the rate of heat transfer is calculated and presented in tabular form. It is noticed that velocity and Nusselt number increase when the thermal buoyancy parameter is enhanced. Moreover, temperature is found to decrease for larger values of Prandtl number and heat absorption parameter. Comparative analysis for limiting study is performed and excellent agreement is found.

Analysis on Unit-Commitment Game in Oligopoly Structure of the Electricity Market (전력시장 과점구조에서의 발전기 기동정지 게임 해석)

  • 이광호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.11
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    • pp.668-674
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    • 2003
  • The electric marketplace is in the midst of major changes designed to promote competition. No longer vertically integrated with guaranteed customers and suppliers, electric generators and distributors will have to compete to sell and buy electricity. Unit commitment (UC) in such a competitive environment is not the same as the traditional one anymore. The objective of UC is not to minimize production cost as before but to find the solution that produces a maximum profit for a generation firm. This paper presents a hi-level formulation that decomposes the UC game into a generation-decision game (first level game) and a state(on/off)-decision game (second level game). Derivation that the first-level game has a pure Cournot Nash equilibrium(NE) helps to solve the second-level game. In case of having a mixed NE in the second-level game, this paper chooses a pure strategy having maximum probability in the mixed strategy in order to obviate the probabilistic on/off state which may be infeasible. Simulation results shows that proposed method gives the adequate UC solutions corresponding to a NE.

Dynamic analysis of helicoidal bars with non-circular cross-sections via mixed FEM

  • Eratli, Nihal;Yilmaz, Murat;Darilmaz, Kutlu;Omurtag, Mehmet H.
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.221-238
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    • 2016
  • One of the objectives of this study is to implement the direct calculation of the torsional moment of inertia for non-circular cross-sections, which is based on the St. Venant torsion formulation and the finite element method. Recently the proposed method provides a unique calculation of the torsional rigidity of simply and multiply connected cross-sections. Next, free vibration analyses of cylindrical and non-cylindrical helices with non-circular cross-sections are solved by a curved two-nodded mixed finite element based on the Timoshenko beam theory. Some thin-thick closed or open sections are handled and the natural frequencies of cylindrical and non-cylindrical helices are compared with the literature and the commercial finite element program SAP2000.

Phase behaviors, lamellar structures, and physical properties of synthetic vitamin E ceramide (Tocomide) mixed with cholesterol and linoleic acid

  • Lee, Young-Jin;Kim, Do-Hoon;Park, Ho-Sik;Kang, Hyung-Seok;Kim, Joong-Soo;Kim, Han-Kon
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.357-368
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    • 2003
  • II-A isotherms and phase behaviors of 'tocomide', a newly synthesized 1,3-bis(N-(2-hydroxyethyl)-tocopherol succinylamino)-2-hydroxypropane, mixed with cholesterol and linoleic acid, was studied for its monolayer miscibility and a stable delivery formulation for antioxidant applications. The monolayer of tocomide and cholesterol was formed in a homogeneously mixed state at air-water interface. The ternary mixtures with linoleic acid showed various bulk structures, including a stable and transparent solution of thermodynamically stable lamellar phase. The lamellar structure was confirmed by the X-ray diffraction (XRD) patterns and polarized microscopy such that pure tocomide formed a liquid crystal at room temperature with a lamellar periodicity of 36.7 $\AA$(2$\theta$=2.41$^{\circ}$).

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In-Plane Flexural Vibration Analysis of Arches Using Three-Noded Hybrid-Mixed Element (3절점 혼합유한요소를 이용한 아치의 면내굽힘진동해석)

  • Kim, J.G.
    • Journal of Power System Engineering
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    • v.10 no.4
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    • pp.83-89
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    • 2006
  • Curved beams are more efficient in transfer of loads than straight beams because the transfer is effected by bending, shear and membrane action. The finite element method is a versatile method for solving structural mechanics problems and curved beam problems have been solved using this method by many author. In this study, a new three-noded hybrid-mixed curved beam element is proposed to investigate the in-plane flexural vibration behavior of arches depending on the curvature, aspect ratio and boundary conditions, etc. The proposed element including the effect of shear deformation is based on the Hellinger-Reissner variational principle, and employs the quadratic displacement functions and consistent linear stress functions. The stress parameters are then eliminated from the stationary condition of the variational principle so that the standard stiffness equations are obtained. Several numerical examples confirm the accuracy of the proposed finite element and also show the dynamic behavior of arches with various shapes.

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Mixed finite element formulation for folded plates

  • Eratli, Nihal;Akoz, A. Yalcin
    • Structural Engineering and Mechanics
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    • v.13 no.2
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    • pp.155-170
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    • 2002
  • In this study, a new functional is obtained for folded plates with geometric (kinematic) and dynamic (natural) boundary conditions. This functional is the combination of two different functionals. Both functionals are obtained for thick plates which carry in-plane and lateral forces. A new mixed finite element is developed with $4{\times}13$ nodal parameters for folded plates (REC52). Forces and moments which are the necessary unknowns in engineering problems are obtained directly using the technique suggested here. The use of the global co-ordinate system causes time consuming operations and therefore the Lagrange multiplier method is used to relate the components of the parameters on the fold line. Numerical results are presented for folded plates and compared with experimental results.

Pharmacokinetic Evaluation of Ketorolac Tromethamine Sustained-Release Pellets after Oral Administration in Rabbits (케토롤락트로메타민 서방성 펠렛의 약물속도론적 평가)

  • Kwak, Son-Hyok;Hwang, Sung-Joo;Jiang, Ge;Nam, Kyung-Wan;Moon, Young-Girl;Lee, Hai-Bang;Cho, Sun-Hang;Yuk, Soon-Hong;Lee, Han-Koo;Jeong, Sang-Young;Lee, Young-Won
    • Journal of Pharmaceutical Investigation
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    • v.30 no.4
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    • pp.241-246
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    • 2000
  • To develop a sustained-release preparation containing ketorolac tromethamine, two sustained-release pellet formulations were evaluated with a pharmacokinetic study as compared with a conventional commercial tablets (10 mg $Tarasyn^{TM}$, Roche Korea Ltd.). Two sustained-release formulations were as follows; formulation A was composed of an inner layer containing 75% of drug coated with $Eudragit^{TM}$ RS 100 membrane and an outer layer containing 25% of drug mixed with $Eudragit^{TM}$ NE30D, and formulation B was composed of only an inner layer containing 100% of drug coated with $Eudragit^{TM}$ RS 100 membrane. The dissolution test was performed for two formulations. In case of conventional tablets, 2.5 mg of drug per a dose was administered orally into male Albino rabbit (2.0-2.3 kg of body weight) 3 times at intervals of 4 hours. In case of two sustained formulations, 7.5 mg of drug was administered once orally. Blood samples were withdrawn periodically after the administration, and the blood concentration was determined by HPLC. The conventional tablets showed very high peak-trough fluctuation between administered doses, but two sustained formulations showed less fluctuation. Formulation A with the loading dose showed the time to reach minimum effective concentration (MEC) i.e. the onset time was less than 20 min, while Formulation B had more than 1 hr of the onset time. Formulation A had the more constant plasma level than formulation B. However, formulation B had a time lag, so the plasma level was less than MEC for an initial period of 1 hr. In formulation A, the plasma level was maintained within the therapeutic window $(0.3-5\;{\mu}g/ml)$ for a long period. Formulation A was thought to be an ideal sustained-release formulation for ketorolac tromethamine oral delivery system.

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Analysis of shallow footings rested on tensionless foundations using a mixed finite element model

  • Lezgy-Nazargah, M.;Mamazizi, A.;Khosravi, H.
    • Structural Engineering and Mechanics
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    • v.81 no.3
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    • pp.379-394
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    • 2022
  • Shallow footings usually belonged to the category of thick plate structures. For accurate analysis of thick plates, the contribution of out-of-plane components of the stress tensor should be considered in the formulation. Most of the available shallow footing models are based on the classical plate theories, which usually neglect the effects of the out-of-plane stresses. In this study, a mixed-field plate finite element model (FEM) is developed for the analysis of shallow footings rested on soil foundations. In addition to displacement field variables, the out-of-plane components of the stress tensor are also assumed as a priori unknown variables. For modeling the interaction effect of the soil under and outside of the shallow footings, the modified Vlasov theory is used. The tensionless nature of the supporting soil foundation is taken into account by adopting an incremental, iterative procedure. The equality requirement of displacements at the interface between the shallow footing and soil is fulfilled using the penalty approach. For validation of the present mixed FEM, the obtained results are compared with the results of 3D FEM and previous results published in the literature. The comparisons show the present mixed FEM is an efficient and accurate tool for solving the problems of shallow footings rested on subsoil.

Effects of mixed formulation of tamoxifen and blue honeysuckle on the pharmacokinetics profiles of tamoxifen after single oral administration

  • Hu, Jin-Ryul;Jang, Tae-Woo;Kang, Su-Jin;Ku, Sae-Kwang;Choi, Seong-Hun;Lee, Young-Joon
    • The Journal of Korean Medicine
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    • v.40 no.4
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    • pp.1-15
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    • 2019
  • Objectives: Here, we investigated the effects of concentrated and lyophilized powders Blue honeysuckle (BH) on the PK of tamoxifen, to establish the pharmacokinetics (PK) profiles as one of essential process in new drug development. Methods: After single oral treatment of 0.4 mg/ml of tamoxifen or tamoxifen 0.4 with BH 40, 20 and 10 mg/ml, the plasma were collected at 0.5 hr before administration, 0.5, 1, 2, 3, 4, 6, 8 and 24 hr after end of single or mixed formula treatment. Plasma concentrations of tamoxifen were analyzed using LC-MS/MS methods. Tmax, Cmax, AUC, t1/2 and MRTinf were analyzed using noncompartmental PK data analyzer programs. Results: Tamoxifen and BH 40 mg/ml did not induce any significant change on the plasma tamoxifen concentrations, while significant decreases were observed in tamoxifen and BH 10 mg/ml from 2 to 8 hr as compared with tamoxifen only, respectively. Furthermore, significant increases of Tmax in tamoxifen and BH 40 mg/ml, significant decreases of Cmax in tamoxifen and BH 20 mg/ml, significant decreases of AUC0-t, AUC0-inf and MRTinf in tamoxifen and BH 10 mg/ml were demonstrated as compared with tamoxifen only. Conclusion: Taken together, tamoxifen and BH 10 mg/ml induced significant decrease of the oral bioavailability of tamoxifen, while tamoxifen and BH 40 or 20 mg/ml did not critically influenced, suggesting formulated BH concentration-independencies. It, therefore, seems to be needed that pharmacokinetic study after repeated administration should be tested to conclude the effects of BH on the pharmacokinetics of tamoxifen.