• 전기학회논문지
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• 제56권1호
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• pp.174-182
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• 2007

In this paper, we study the influence of infection ratio on gradual reduction of drug dose for the five state HIV infection model that explicitly includes the population of the virus. We first compute all equilibrium points of the model and investigate the stabilities of them. As a result, a bifurcation diagram is obtained which shows a change in the equilibrium points, or in their stability properties, as the drug effect $\eta$ is varied from 0 to 1(alternatively, drug dose is changed from 1 to 0). Based on the bifurcation diagram, we show that the gradual reduction of drug dose can be applied for the treatment of AIDS patients. Moreover, we analyze the influence of the variation of infection ratio on the gradual reduction treatment. Computer simulation results are also presented to validate the proposed results.

• Environmental Analysis Health and Toxicology
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• 제18권1호
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• pp.63-67
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• 2003

Benzoic acid is produced about 700 tons/year in Korea as of 1998 survey. Most is used as a stabilizer in the processes of synthesis of pharmaceuticals and dyes. It is also used for ingradient of paint, disinfections, and antifungals. Due to the antioxidant activity of benzoic acid, the chemical is also used as food preservatives. Although the chemical is widely used in Korea, exposure levels in air, water, soil or sediment have not been monitored or estimated so that risk evaluation of benzoic acid was not possible. In this study, distribution of the chemical among environmental media was estimated using EQC model based on the chemical-physical properties. In Level I and II of which the chemical are hypothesized in equilibrium and no transfer through the media, more than 93％ of benzoic acid are estimated to be distributed in water. However, in Level III of which non-equilibrium and intermedia transfer could be occurred, the chemical is estimated to distributed to soil, 64％ and water,35% as of total amount.

• 대한기계학회논문집B
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• 제26권7호
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• pp.983-990
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• 2002

A numerical analysis has been carried out on forced convection heat transfer in the developing region of a porous channel. The channel is filled with an isotropic porous medium. At the channel walls, a uniform heat flux is given. Comprehensive numerical solutions are acquired to the Brinkman-Forchheimer extended Darcy equation and the LTNE model which does not employ the assumption of local thermal equilibrium between solid and fluid phases. Details of thermal fields in the developing region are examined over wide ranges of the thermal parameters. The numerical solutions at the fully developed region are compared with the previous analytical solutions. The correlation for predicting local Nusselt number in a porous channel is proposed.

• 한국포장학회지
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• 제4권1호
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• pp.11-16
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• 1997

Sorption studies involving the sorption of n-propanol by an Amorphous Nylon(Nylon 6I/6T) were carried out as a function of sorbate vapor activity at $23^{\circ}C$. Vapor activity levels from 0.035 to 0.91 were investigated to evaluate the concentration dependency of sorption mechanism. Sorption behavior of propanol by Nylon 6I/6T showed distinctive two mode sorption phenomena as a function of Vapor activity. At Vapor activity levels below a=0.11, equilibrium sorption was achieved within a short period of time(less than 20hrs), which can be interpreted as following a Fickian diffusion model. A Langmuir-Flory-Muggins Dual Mode Sorption model can also be applied at these concentration levels. However, for Vapor activities above a=0.11, the sorption process appeared to be non-Fickian and resulted in a lack of equilibrium being attained.

• 한국경영과학회지
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• 제27권1호
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• pp.19-32
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• 2002

This paper examines the effect of the producer-supplier quality contract parameters and the magnitude of the quality related variables on the quality of the final products. Our analysis focuses on the parties' equilibrium behavior In a quality game environment where the supplier should choose among the two production technologies, one requiring high cost but producing high quality Parts and the other requiring low cost but producing low quality parts and where the producer should decide whether to do the inspection of the parts. The game framework is employed to depict the potential conflicts existing between the Producer and the supplier because the Producer can not observe the supplier's choice and each party wants the other to bear the cost of producing high quality products. In our model, we specifically consider the competitive situation where the producer competes with a firm producing the same product. We employ the market share attraction model to Incorporate the competitive situation and completely characterize the equilibrium by using the Nash equilibrium concept for the game solution. Our results show that the equilibrium depends on the contract terms and the magnitude of the quality related variables. Compared to the non-competitive situation, the probability of producer's Inspection and the probability of supplier's choosing the high quality technology increases in a competitive situation. This is true even when the competitor's quality is lower than the producer's lowest. As a result, the quality of the final product increases In a competitive situation. And as the failure cost borne by the supplier increases, the probability of choosing the high quality technology Increases and the probability of inspection decreases. The net effect of this results in the decrease of the final product quality.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.132-132
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• 2009

A 2D-simulation using a quantum model of silicon nanowire (SiNW) field-effect transistors (FETs) have been performed by the effective mass theory. We have investigated very close for real device analysis, so we used to the non-equilibrium Green's function (NEGF) and the density gradient of quantum model. We investigated I-V characteristics curve and C-V characteristics curve of the channel thickness from 5nm to 200nm. As a result of simulation, even higher drain current in SiNW using a quantum model was observed than in SiNW using a non-quantum model. The reason of higher drain current can be explained by the quantum confinement effect.

• Journal of applied mathematics & informatics
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• 제26권1_2호
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• pp.337-347
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• 2008

Based on social welfare maximum theory, the optimal scale of power plants entering generation power market being is researched. A static non-cooperative game model for short-term optimization of power plants with different cost is presented. And the equilibrium solutions and the total social welfare are obtained. According to principle of maximum social welfare selection, the optimization model is solved, optimal number of power plants entering the market is determined. The optimization results can not only increase the customer surplus and improve power production efficiency, but also sustain normal profits of power plants and scale economy of power production, and the waste of resource can also be avoided. At last, case results show that the proposed model is efficient.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.753-759
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• 2011

The HIV (Human Immunodeficiency Virus) causes AIDS (Acquired Immune Deficiency Syndrome). The process of infection and mutation by HIV can be described by a 3rd order state equation. For this HIV model that includes the dynamics of the mutant virus, we present a parameter estimation scheme using two state variables sporadically measured, out of the three, by employing a genetic algorithm. It is assumed that these non-uniformly sampled measurements are subject to random noises. The effectiveness of the proposed parameter estimation is demonstrated by simulations. In addition, the estimated parameters are used to analyze the equilibrium points of the HIV model, and the results are shown to be consistent with those previously obtained.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.229-233
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• 2003

This paper describes a practical formulation of Non-Bernoulli-Compatibility Truss Model. Not only equilibrium conditions but also some approximations are employed to solve for the unknowns included in the proposed model. By assuming that the ratio of $V_a$ to V remains to be constant along the shear span, the relationship between $\alpha$ and z is mathematically established as an arch shape function. $V_m$ is also approximated to be an empirical value that is equal to the least membrane shear strength. The coefficient a is made utilizing a nonlinear finite element analysis. The adequacy of the model is examined by test results available in literatures, and the predicted values are shown to be in excellent agreement with the experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2286-2309
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• 2016

Overlay networks have been widely deployed upon the Internet by Service Providers (SPs) to provide improved network services. However, the interaction between each overlay and traffic engineering (TE) as well as the interaction among co-existing overlays may occur. In this paper, we adopt both non-cooperative and cooperative game theory to analyze these interactions, which are collectively called hybrid interaction. Firstly, we model a situation of the hybrid interaction as an n+1-player non-cooperative game, in which overlays and TE are of equal status, and prove the existence of Nash equilibrium (NE) for this game. Secondly, we model another situation of the hybrid interaction as a 1-leader-n-follower Stackelberg-Nash game, in which TE is the leader and co-existing overlays are followers, and prove that the cost at Stackelberg-Nash equilibrium (SNE) is at least as good as that at NE for TE. Thirdly, we propose a cooperative coalition mechanism based on Shapley value to overcome the inherent inefficiency of NE and SNE, in which players can improve their performance and form stable coalitions. Finally, we apply distinct genetic algorithms (GA) to calculate the values for NE, SNE and the assigned cost for each player in each coalition, respectively. Analytical results are confirmed by the simulation on complex network topologies.