• Journal of Communications and Networks
• /
• v.13 no.1
• /
• pp.26-31
• /
• 2011

In this paper, we formulate the minimum power multicast problem in wireless networks as a mixed integer linear programming problem and then propose a Lagrangean relaxation based algorithm to solve this problem. By leveraging on the information from the Lagrangean multiplier, we could construct more power efficient routing paths. Numerical results demonstrate that the proposed approach outperforms the existing approaches for broadcast, multicast, and unicast communications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.246-248
• /
• 2021

Recently data has been transformed into a data economy and society that acts as a catalyst for the development of all industries and the creation of new value, and COVID-19 is accelerating digital transformation. In the upcoming intelligent Internet of Things era, the availability of decentralized systems such as blockchain and mixnet is emerging to solve the security problems of centralized systems that makes it difficult to utilize data safely and efficiently. Blockchain manages data in a transparent and decentralized manner and guarantees the reliability and integrity of the data through agreements between participants, but the transparency of the data threatens the privacy of users. On the other hand, mixed net technology for protecting privacy protects privacy in distributed networks, but due to inefficient power consumption efficiency and processing speed issues, low cost, light weight, low power consumption Internet Hard to use. In this paper, we analyze the limitations of conventional mixed-net technology and propose a mixed-net technology method for low power consumption, high speed, and the Internet of things.

• Journal of Power System Engineering
• /
• v.18 no.1
• /
• pp.69-75
• /
• 2014

The pressure and temperature characteristics of mixed refrigerant gases in bulb for thermostatic expansion valve were studied using R22 refrigerant and $N_2$ gases. The characteristics of mixed refrigerant gases were investigated according to pressure variation and the variation of composition ratio of R22 refrigerant and $N_2$ gases in the temperature range of -$15^{\circ}C$~$15^{\circ}C$. The Maximum operating pressure(MOP) of mixed refrigerant gases were showed a tendency to decrease with decreasing the mixing ratio of $N_2$ gas. The characteristics in the case of the mixing ratio of 90:1 for R22 refrigerant and $N_2$ gases were the same result as Reference refrigerant. In addition, the characteristics of the mixed refrigerant gases in the mixing ratio of 90:1 for R22 refrigerant and $N_2$ gases were showed almost linear in the measurement range of pressure-temperature, and the physical properties also were showed similar results with Reference refrigerant. It was able to confirm that a MOP on the thermostatic expansion valve for sensing bulb can be maintained by adjusting the mixing ratio of R22 refrigerant and $N_2$ gases.

• Journal of Mechanical Science and Technology
• /
• v.15 no.6
• /
• pp.685-692
• /
• 2001

This paper reports on the mixed lubrication characteristics between the cam and the tappet contact surface of direct acting type valve train systems. First, the dynamic characteristics are solved by using the lumped mass method to determine the load conditions at the contact point. Then, the minimum oil film thickness is calculated with consideration of elastohydrodynamic line contact theory and the friction force is obtained by using the mixed lubrication model which separates the hydrodynamic and the boundary friction. Finally, the average surface temperatures are calculated by using the flash temperature theory. The results show that, there are some peaks in the friction force due to the asperity contact friction, and flash temperature at the position of minimum oil film thickness. It is thought that there is a relationship between the surface temperature and cam surface wear, and therefore, the analysis on the worn cam profile has been performed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.16 no.3
• /
• pp.359-367
• /
• 2018

Long-lived Small Modular Reactors are being promoted as an innovative way of catering to emerging markets and isolated regions. They can be operated continuously for decades without requiring additional fuel. A novel configuration of long-lived reactor core employs a mixed neutron spectrum, providing an improvement in nonproliferation metrics and in safety characteristics. Starting with a base sodium reactor design, moderating material is inserted in outer core assemblies to modify the fast spectrum. The assemblies are shuffled once during core lifetime to ensure that every fuel rod is exposed to the thermalized spectrum. The Mixed Spectrum Reactor is able to maintain a core lifetime over two decades while ensuring the plutonium it breeds is below the weapon-grade limit at the fuel discharge. The main drawbacks of the design are higher front-end fuel cycle costs and a 58% increase in core volume, although it is alleviated to some extent by a 48% higher power output.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2786-2788
• /
• 1999

In this paper, a mixed mode exciting resonant inverter topology applicable to high performance electronic ballast is presented. Mixed mode exciting technique combines the attractive features of self exciting resonant inverter with those of external exciting one. The control IC is designed and manufactured by using a 0.8um CMOS process for 5V operation and has only 8 pins. This performs the operations of filament preheating, dimming control, output power regulation and protections. The mixed mode exciting resonant inverter with control IC has very simple structure, high performance and expensive manufacturing cost.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.538-543
• /
• 2000

The purpose of this study is to develope electrostatic separation system for recycling of mixed waste plastics. The electrostatic separation system is designed and investigated the separation efficiency for separating of mixed waste plastics. Electrostatic separation system consisted of a tribocharger, separator (two electrode), collector (5 tray) and controller (positive/negative high voltage power supply). The tribocharger is a fluidized bed using tribo-electrification mechanism between particles and particles. In experimental results, the tribocharger of the fluidized bed was more effective separation efficiency. It showed the purity of $85{\sim}99\;%$ and the recovery of $80{\sim}98\;%$ from the powder of mixed plastics such as LDPE, HDPE, PP, PS, PET and PVC. Especially, In the separation experiment of Polyvinylchloride(PVC) which generates hazardous hydrogen chloride gas in case of the combustion. its purity was over 99 % and recovery was over 95 %.

• International Journal of Fluid Machinery and Systems
• /
• v.4 no.1
• /
• pp.172-178
• /
• 2011

This paper presents an optimization procedure for high-efficiency design of a mixed-flow pump. Optimization techniques based on a weighted-average surrogate model are used to optimize a vane diffuser of a mixed-flow pump. Validation of the numerical results is performed through experimental data for head, power and efficiency. Three-level full factorial design is used to generate nine design points within the design space. Three-dimensional Reynoldsaveraged Navier-Stokes equations with the shear stress transport turbulence model are discretized by using finite volume approximation and solved on hexahedral grids to evaluate the efficiency as the objective function. In order to reduce pressure loss in the vane diffuser, two variables defining the straight vane length ratio and the diffusion area ratio are selected as design variables in the present optimization. As the results of the design optimization, the efficiency at the design flow coefficient is improved by 7.05% and the off-design efficiencies are also improved in comparison with the reference design.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.4
• /
• pp.675-685
• /
• 2013

Generation capacities and transmission line constraints in a competitive electricity market make it troublesome to compute Nash Equilibrium (NE) for analyzing participants' strategic generation quantities. The NE can cause a mixed strategy NE rather than a pure strategy NE resulting in a more complicated computation of NE, especially in a multiplayer game. A two-level hierarchical optimization problem is used to model competition among multiple participants. There are difficulties in using a mathematical programming approach to solve a mixed strategy NE. This paper presents heuristics applied to the mathematical programming method for dealing with the constraints on generation capacities and transmission line flows. A new formulation based on the heuristics is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations.

• International Journal of Computer Science & Network Security
• /
• v.24 no.1
• /
• pp.85-94
• /
• 2024

In this paper, we present the very first time the generalized notion of (α, β, γ, δ) - convex (concave) function in mixed kind, which is the generalization of (α, β) - convex (concave) functions in 1^st and 2^nd kind, (s, r) - convex (concave) functions in mixed kind, s - convex (concave) functions in 1^st and 2^nd kind, p - convex (concave) functions, quasi convex(concave) functions and the class of convex (concave) functions. We would like to state the well-known Ostrowski inequality via SVN-Riemann Integrals for (α, β, γ, δ) - convex (concave) function in mixed kind. Moreover we establish some SVN-Ostrowski type inequalities for the class of functions whose derivatives in absolute values at certain powers are (α, β, γ, δ)-convex (concave) functions in mixed kind by using different techniques including Hölder's inequality and power mean inequality. Also, various established results would be captured as special cases with respect to convexity of function.