• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.403-414
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• 1994

Nonlinear analysis of RC containment structure under thermal load and pressure is presented to trace the behaviour after an assumed LOCA. The temperature distribution varying with time through the wall thickness is determined by transient finite element analysis with the two time level scheme in time domain. The layered shell finite elements are used to represent the containment structures in nuclear power plants. Both geometric and material nonlinearities are taken into account in the finite element formulation. The constitutive relation of concrete is modeled according to Drucker-Prager yield criteria in compression. Tension stiffening model is used to represent the tensile behaviour of concrete including bond effect. The reinforcing bars are modeled by smeared layer at the location of reinforcements accounting elasto-plastic axial behaviors. The steel liner model under Von Mises yield criteria is adopted to represent elastic-perfect plastic behaviour. Geometric nonlinearity is formulated to consider the large displacement effect. Thermal stress components are determined by the initial strain concept during each time step. The temperature differential between any two consecutive time steps is considered as a load incremental. The numerical results from this study reveal that nonlinear temperature gradient based on transient thermal analysis will produces excessive large displacement. Nonlinear behavior of containment structures up to ultimate stage can be traced reallistically. The present study allows more realistic analysis of concrete containment structures in nuclear power plants.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.195-204
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• 2004

A novel glucanhydrolase from Lipomyces starkeyi KSM 22 has been suggested as a promising anti-plaque agent because it has been shown to have additional amylase activity and mutanase activity besides dextranase activity and to strongly bind to hydroxyapatite. Mouthrinsing with Lipomyces starkeyi KSM 22 glucanhydrolase solution was comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effects were less frequent and less intense in human experimental gingivitis. In this study, Lipomyces starkeyi KSM 22 glucanhydrolase mouthrinses (1 and 2 unit/ml) were compared with a control mouthrinse (commercial 0.01% benzethonium chloride mouthrinse, $Caregargle^{(R)}$, Hanmi Pharmaceuticals) in the ability to inhibit plaque formation. A 3-replicate clinical trial using 4-day plaque regrowth model was used. Fifteen volunteers were rendered plaque-free on the 1st day of each study period, ceased toothcleansing, and rinsed 2X daily with allocated mouthrinse thereafter. On day 5, plaque accumulation was scored and the washout periods was 9 days for the next trial. Lipomyces starkeyi KSM22 glucanhydrolase(1 unit and 2 unit)- containing mouthrinse resulted in Significantly lower plaque formation in plaque area and thickness, compared to the control mouthrinse. There was no significant difference in plaque inhibition between enzyme-mouthrinses at 2 different concentrations used. This glucanhydrolase- containing mouthwash resulted in significantly lower plaque area severity index score and tended to have lower plaque thickness severity index score than those of control mouthrinse. But there was no significant difference according to the enzyme concentration. From these results, Lipomyces starkeyi KSM 22 glucanhydrolase-containing benzethonium chloride mouthrinse has greater anti-plaque effect than the commercial mouthrinse alone. Therefore this glucanhydrolase preparation is a promising agent for new mouthwash formulation in the near future.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.69-89
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• 2009

Reinforced and prestressed concrete (RC and PC) thin walls are crucial to the safety and serviceability of structures subjected to shear. The shear strengths of elements in walls depend strongly on the softening of concrete struts in the principal compression direction due to the principal tension in the perpendicular direction. The past three decades have seen a rapid development of knowledge in shear of reinforced concrete structures. Various rational models have been proposed that are based on the smeared-crack concept and can satisfy Navier's three principles of mechanics of materials (i.e., stress equilibrium, strain compatibility and constitutive laws). The Cyclic Softened Membrane Model (CSMM) is one such rational model developed at the University of Houston, which is being efficiently used to predict the behavior of RC/PC structures critical in shear. CSMM for RC has already been implemented into finite element framework of OpenSees (Fenves 2005) to come up with a finite element program called Simulation of Reinforced Concrete Structures (SRCS) (Zhong 2005, Mo et al. 2008). CSMM for PC is being currently implemented into SRCS to make the program applicable to reinforced as well as prestressed concrete. The generalized program is called Simulation of Concrete Structures (SCS). In this paper, the CSMM for RC/PC in material scale is first introduced. Basically, the constitutive relationships of the materials, including uniaxial constitutive relationship of concrete, uniaxial constitutive relationships of reinforcements embedded in concrete and constitutive relationship of concrete in shear, are determined by testing RC/PC full-scale panels in a Universal Panel Tester available at the University of Houston. The formulation in element scale is then derived, including equilibrium and compatibility equations, relationship between biaxial strains and uniaxial strains, material stiffness matrix and RC plane stress element. Finally the formulated results with RC/PC plane stress elements are implemented in structure scale into a finite element program based on the framework of OpenSees to predict the structural behavior of RC/PC thin-walled structures subjected to earthquake-type loading. The accuracy of the multiscale modeling technique is validated by comparing the simulated responses of RC shear walls subjected to reversed cyclic loading and shake table excitations with test data. The response of a post tensioned precast column under reversed cyclic loads has also been simulated to check the accuracy of SCS which is currently under development. This multiscale modeling technique greatly improves the simulation capability of RC thin-walled structures available to researchers and engineers.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.107-117
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• 2004

The growing demand for customer-response, made-to-order manufacturing and satisfactory delivery are stimulating the importance of commercial fleet management problem. Moreover, the rapid transformation to the customer-oriented multi-frequency, relatively small fleet, such as home delivery and Perishable goods, requiring prompt delivery and advanced real-time operation of vehicle fleets. In this paper we consider the vehicle routing problem(VRP) to minimize delivery completion time which is equal to the time that last customer wait for the vehicle in fleet operation. The mathematical formulation is different from those for the classical VRP which is minimizing cost/distance/time by running vehicles in manager's point of view. The key aspect of this model is not considering the return time from the last customer to depot in every vehicle path. Thereby, the vehicle dispatcher can afford to dynamically respond to customer demand and vehicle availability. The customer's position concerned with minimizing waiting time that may be applied for the delivery of product required freshness or delivery time. Extensive experiments are carried out to compare the performance of minimizing delivery completion time by using the ILOG Solver which has the advantage of solving quickly an interim solution very near an optimal solution. The experimental results show that the suggested model can easily find near optimal solution in a reasonable computational time under the various combination of customers and vehicles.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.175-184
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• 2015

The purpose of this study was to determine the optimal mixing ratio of Agaricus blazei Murill powder and butter in the preparation of cookies. The experimental design utilized herein was based on central composite design for response surface methodology, which included 10 experimental points, including 2 replicates for Agaricus blazei Murill and butter. The physical, mechanical, and sensory properties of the test were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the final mixed product. The spread ratio increased significantly with an increase in Agaricus blazei Murill powder and butter (p<0.05). The response surface methodology was applied to evaluate the effect of Agaricus blazei Murill powder and butter on cookie moisture and color (L, a) (p<0.001). Sensory evaluation showed significant values for color (p<0.05), flavor (p<0.05), texture (p<0.05) and overall quality (p<0.01) in the predicted model. The optimum formulation by numerical and graphical methods was calculated as follows: Agaricus blazei Murill powder 3.63 g, butter 55.37 g.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.697-704
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• 2008

This paper presents an analytical prediction of Nonlinear characteristics of prestressed concrete bridges by strengthened of externally tendon considering construction sequence, using unbonded tendon element and beam-column element based on flexibility method. Unbonded tendon model can represent unbounded tendon behavior in concrete of PSC structures and it can deal with the prestressing transfer of posttensioned structures and calculate prestressed concrete structures more efficiently. This tendon model made up the several nodes and segment, therefore a real tendon of same geometry in the prestressed concrete structure can be simulated the one element. The beam-column element was developed with reinforced concrete material nonlinearities which are based on the smeared crack concept. The fiber hysteresis rule of beam-column element is derived from the uniaxial constitutive relations of concrete and reinforcing steel fibers. The formulation of beam-column element is based on flexibility. Beam-column element and unbonded tendon element were be involved in A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), that were used the analysis of RC and PSC structures. The proposed numerical method for prestressed concrete structures by strengthened of externally tendon is verified by comparison with reliable experimental results.

• Progress in Superconductivity and Cryogenics
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• v.15 no.2
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• pp.34-38
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• 2013

AC Losses for face to face stacks of four identical coated conductors (CCs) were numerically calculated using the H-formulation combined with the E-J power law and the Kim model. The motive sample was the face to face stack of four 2 mm-wide CC tapes with 2 ${\mu}m$ thick superconducting layer of which the critical current density, $J_c$, was $2.16{\times}10^6A/cm^2$ on IBAD-MgO template, which was suggested for the mitigation of ac loss as a round shaped wire by Korea Electrotechnology Research Institute. For the calculation the cross section of the stack was simply modeled as vertically aligned 4 rectangles of superconducting (SC) layers with $E=E_o(J(x,y,t)/J_c(B))^n$ in x-y plane where $E_o$ was $10^{-6}$ V/cm, $J_c$(B) was the field dependence of current density and n was 21. The field dependence of the critical current of the sample measured in four-probe method was employed for $J_c$(B) in the equation. The model was implemented in the finite element method program by commercial software. The ac loss properties for the stacks were compared with those of single 4 cm-wide SC layers with the same critical current density or the same critical current. The constraint for the simulation was imposed in two different ways that the total current of the stack obtained by integrating J(x,y,t) over the cross sections was the same as that of the applied transport current: one is that one fourth of the external current was enforced to flow through each SC. In this case, the ac loss values for the stacks were lower than those of single wide SC layer. This mitigation of the loss is attributed to the reduction of the normal component of the magnetic field near the SC layers due to the strong expulsion of the magnetic field by the enforced transport current. On the contrary, for the other case of no such enforcement, the ac loss values were greater than those of single 4cm-wide SC layer and. In this case, the phase difference of the current flowing through the inner and the outer SC layers of the stack was observed as the transport current was increased, which was a cause of the abrupt increase of ac loss for higher transport current.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.18
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• pp.27-62
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• 2002

The international sale contract is the central contracts in export-import transactions. A good sale contract or set of general conditions of sale will cover all the principal elements of the transaction, so that uncertainties are avoided. The parties' respective duties as concern the payment mechanism, transport contract and insurance responsibilities, inter alia, will all be clearly detailed in the contract. The following key clauses should be included in international contracts of sale and general conditions of sale: ${\bullet}$ preamble ${\bullet}$ identification of parties ${\bullet}$ description of goods ${\bullet}$ price and payment conditions ${\bullet}$ delivery periods and conditions ${\bullet}$ inspection of the goods - obligations and limitations ${\bullet}$ quantity or quality variations in the products delivered ${\bullet}$ reservation of title and passing of property rights ${\bullet}$ transfer of risk - how accomplished ${\bullet}$ seller's warranties and buyer's complaints ${\bullet}$ assignment of rights ${\bullet}$ force majeure clause and hardship clause ${\bullet}$ requirement that amendments and modifications be in writing ${\bullet}$ choice of law ${\bullet}$ choice of dispute resolution mechanism Under most systems of law, a party can be excused from a failure to perform a contract obligation which is caused by the intervention of a totally unforeseeable event, such as the outbreak of war, or an act of God such as an earthquake or hurricane. Under the American commercial code (UCC) the standard for this relief is one of commercial impracticability. In contrast, many civil law jurisdictions apply the term force majeure to this problem. Under CISG, the standard is based on the concept of impediments to performance. Because of the differences between these standards, parties might be well advised to draft their own force majeure, hardship, or excusable delays clause. The ICC publication, "Force Majeure and Hardship" provides a sample force majeure clause which can be incorporated by reference, as well as a hardship clause which must be expressly integrated in the contract. In addition, the ICC Model provides a similar, somewhat more concise formulation of a force majeure clause. When the seller wishes to devise his own excusable delays clause, he will seek to anticipate in its provision such potential difficulties as those related to obtaining government authorisations, changes in customs duties or regulations, drastic fluctuations in labour, materials, energy, or transportation prices, etc.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.87-90
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• 2006

The aim of the present study was to investigate the disposition pharmacokinetics of roxithromycin in broilers. Roxithromycin was administered at a single dose of 20 mg/kg body weight by intravenous (i.v.) routes. Plasma concentrations of roxithromycin were determined by liquid chromatography/mass spectrometry. After a single i.v. dose plasma concentrations were best fitted to a two-compartment open model. The values of the pharmacokinetic parameters after i.v. administration were: elimination half-life = $5.83{\pm}1.79h$, mean residence time = $6.33{\pm}0.32h$, total body clearance = $0.55{\pm}0.15L/h/kg$, and volume of distribution at steady state = $3.47{\pm}0.84L/kg$. The pharmacokinetic interpretation of roxithromycin after i.v. administration revealed that the drug was well distributed throughout the body in broilers and slowly eliminated. More studies for the application of roxithromycin against poultry disease are needed to establish a suitable pharmaceutical formulation, propose optimum dosage regimens, investigate clinical efficacy and study the tolerability of repeated doses.

• The Journal of Engineering Geology
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• v.9 no.3
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• pp.187-206
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• 1999

A computer program to numerically predict the permeability tensor of fractured rocks is developed using information on discontinuities which Borehole Televiewer and Borehole Image Processing System (BIPS) provide. It uses orientation and thickness of a large number of discontinuities as input data, and calculates relative values of the 9 elements consisting of the permeability tensor by the formulation based on the EPM model, which regards a fractured rock as a homogeneous, anisotropic porous medium. In order to assess feasibility of the program on field sites, the numerically calculated tensor was obtained using BIPS logs and compared to the results of pumping test conducted in the boreholes of the study area. The degree of horizontal anisotropy and the direction of maximum horizontal permeability are 2.8 and $N77^{\circ}CE$, respectively, determined from the pumping test data, while 3.0 and $N63^{\circ}CE$ from the numerical analysis by the developed program. Disagreement between two analyses, especially for the principal direction of anisotropy, seems to be caused by problems in analyzing the pumping test data, in applicability of the EPM model and the cubic law, and in simplified relationship between the crack size and aperture. Aside from these problems, consideration of hydraulic parameters characterizing roughness of cracks and infilling materials seems to be required to improve feasibility of the proposed program. Three-dimensional assessment of its feasibility on field sites can be accomplished by conducting a series of cross-hole packer tests consisting of an injecting well and a monitoring well at close distance.