• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.171-177
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• 2001

The adhesion enhancement from inserting a RF bias-sputtered Cr layer between Cu and polyimide (PI) has been studied. The RF bias power applied in this study was ranged from 0 to 400 W. Without the RF bias, the peel strength, which measures the adhesion strength, was nearly o g/mm. As the RF power was increased, the peel strength rose up to ~130 g/mm at 200 W, which remained constant with further increase of the RF bias power. Cross-sectional transmission electron microscopy(TEM) was used to investigate the interfacial reaction between the Cr film and PI substrate during the bias sputtering. The Cr/PI interface without the application of RF dais showed a clean, sharp interface while the RF raised Cr/PI interface had about 10~30 nm thick atomistically mixed interlayer between the metal film and PI substrate. This interlayer appeared to have resulted from the implantation of high energy adatoms during the RF bias sputtering of Cr film. This mixed layer serves as an interlocking layer, which enhances adhesion between the metal and PI layers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.949-966
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• 2013

Recently, Wireless Body Area Network (WBAN) has promise to revolutionize human daily life. The need for multiple sensors and constant monitoring lead these systems to be energy hungry and expensive with short operating lifetimes. In this paper, we offer a review of existing work of WBAN and focus on energy-aware management in it. We emphasize that nodes computation, wireless communication, topology deployment and energy scavenging are main domains for making a long-lived WBAN. We study the popular power management technique Dynamic Voltage and Frequency Scaling (DVFS) and identify the impact of slack time in Dynamic Power Management (DPM), and finally propose an enhanced dynamic power management method to schedule scaled jobs at slack time with the goal of saving energy and keeping system reliability. Theoretical and experimental evaluations exhibit the effectiveness and efficiency of the proposed method.

• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.1990-1997
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• 2020

To support the safe operation of the Miniature Neutron Source Reactor (MNSR), a thermo-hydraulic transient model using the RELAP5/Mod3.2 code was simulated. The model was verified by comparing the results with the measured and the previously calculated data. The comparisons consisted of comparing the MNSR parameters under normal constant power operation and reactivity insertion transients. Reactivity Insertion Accident (RIA) for three different initial reactivity values of 3.6, 6.0, and 6.53 mk have been simulated. The calculated peaks of the reactor power, fuel, clad and coolant temperatures in hot channel were calculated in this model. The reactor power peaks were: 103 kW at 240 s, 174 kW at 160 s and 195 kW at 140 s, respectively. The fuel temperature reached its maximum value of 116 ℃ at 240 s, 124 ℃ at 160 s and 126 ℃ at 140 s respectively. These calculation results ensured the high inherently safety features of the MNSR under all phases of the RIAs.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1392-1401
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• 2015

Inverter configurations for multiple-load induction cooking applications need development. Inverter configurations for induction cooking applications are used in home appliances based on single coil inverters. For multiple-load configurations, multiple coils are used. They require proper inverters, which provide independent control for each load and have fewer components. This paper presents a three-leg inverter configuration for three load induction cooking applications. Each induction coil powers one induction cooking load. This configuration operates with constant switching frequency and powers individual loads. The output power of the required load is controlled with a phase-shift control technique. This configuration is simulated and experimentally tested with three induction loads. The simulation and experimental results are in good agreement. This configuration can be extended to more loads.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.175-183
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• 1999

For fast response of the dc output voltage in P\hi1'v1 converter, it is desirable that the relation of power balance of the i input and output terminals is introduced to the system modeling. In this case, controller desi밍1 is not easy since the m model is nonlinear. In this paper, a nonlinear control them${\gamma}$ using input-output feedback linearization is used to solve t the nonlinear problem of the system. By nonlinear control. the voltage transient response can be faster, and it is also p possible to control the output voltage to be constant with smaller output filter capacitance for load disturbance.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.12
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• pp.594-602
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• 1986

This paper proposes an effective algorithm for short-term generation scheduling for the purpose of economic and secure operation of thermal power systems. Especially, in the procedure of solution by Dynamic Programming, Linear Programming is introduced to promote the possibility of optimal solution and the security of power systems, and evaluation of security function is improved by the application of seven step approximation of normal distribution. Several necessary considerations, that is, time dependent start-up and constant down cost of generating units, demand and spinning reserve constraints, minimum up and sown time constraints, the number of possible start-up of a generating unit in a d and the number of generating units which can be started up at the same time at the same bus, are also incoporated to elevate the usability and flexibility of the algorithm. Finally, the effectiveness of the proposed algorithm has been demonstrated by applying to the 6-gen. 21-bus model power system.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.83-85
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• 2003

This paper presents a speed control of permanent magnet synchronous motors (PMSM) using an adaptive integral binary observer without speed and position sensors. In view of composition with a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. In order to improve the steady state performance of the binary observer, the proposed adaptive integral binary observer is formed by adding extra integral dynamics to the switching hyperplane equation. The effectiveness of the proposed system is conformed by the experimental results.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.278-282
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• 2003

This paper presents TPS(Train Performance Simulation) which identified the condition of train operationing in short time. Using the program, the location of train, maximum current, metering power and regenerating of train, could be identified. This is an important part for Power Simulation. It is supposed that the grade, the curve, the limit speed and the current speed be constant within the time step in the conventional papers. In addition, the errors of the grade and the curve in each station interval are neglected. This paper will introduce improvement method the problem of TPS.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.402-407
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• 2002

A commercial CFD code is applied to analyze the 3-D viscous flow field within vertical multi-stage centrifugal pimp including impeller with 6 blades and guide vane with 11 blades and is performed by changing flow rate from 10 to $26\;m^3/h$ at the constant 3500rpm. The purpose of this 3-D numerical simulation is to confirm how much the effect of blade inlet angle of guide vane has an influence on the performance of vertical multi-stage centrifugal pimp. these results performed by $20^{\circ},\;30^{\circ}$ inlet angle of guide vane are compared with grundfos performance data. The vertical multi-stage pump consist of the impeller, guide vane, and cylinder. The characteristics such as total pressure coefficient total heat shaft horse power, power efficiency, discharge coefficient are represented according to flow rate changing.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.412-414
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• 1994

A new active resonant snubber (ARS) circuit providing the ideal switching conditions for PWM converter is presented. By using the proposed ARS circuit to PWM converters, the power switches can be operated to give zero-current and zero-voltage at both the instant of switch off and switch on, without increasing voltage/current stresses of the switches. Furthermore, the PWM converters employed ARS circuit has the advantage that it can operate at constant frequency, giving better definded EMI and filter ripple, and it is also suited for high-power application regardless of the semiconductor devices (such as MOSFETs or IGBTs) used as a power switches.