• Journal of Power System Engineering
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• v.13 no.6
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• pp.110-116
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• 2009

In the present study, we proposed a simulation model of vacuum booster with AMESIM software to predict the output characteristic. And we performed the sensitivity analysis of output characteristic with main design parameters, such as diaphragm diameter. All of these parameters are main design parameters in the procedure of vacuum booster design. The simulation results of this paper offer qualitative information of vacuum booster output. Therefore, the simulation results of this paper will be used effectively for the design procedure of vacuum booster in the industrial field.

• The KSFM Journal of Fluid Machinery
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• v.8 no.3 s.30
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• pp.42-47
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• 2005

Effects of a booster inducer on the suction performance of turbopumps are investigated in this paper. To see the effect of the booster inducer, suction performance tests are conducted with and without the booster inducer for three turbopumps. It is shown that the booster inducer can enhance the suction performance of turbopumps when the tip clearance of the main inducers are relatively large. Numerical analysis are also carried out to see the effects of the booster inducer on the performance of the main inducer. The booster inducer is shown to increase the static pressure at the inlet of the main inducer and prevent growing of inlet back flows which are believed to have deleterious effects on the suction performance of the inducer.

• Journal of Power Electronics
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• v.13 no.4
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• pp.584-591
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• 2013

In this paper, a hybrid booster power module with Si IGBT and Silicon Carbide (SiC) Schottky Barrier Diode (SBDs) is presented. The switching characteristics of the hybrid booster module are compared with commercial Silicon IGBT/Si PIN diode based modules. We applied the booster power module into a non-isolated on board vehicle charger with a simple buck-booster topology. The performances of the on-vehicle charger are analyzed and measured with different power modules. The test data is measured in the same system, at the same points of operation, using the conventional Si and hybrid Si/SiC power modules. The measured power conversion efficiency of the proposed on-vehicle charger is 96.4 % with the SiC SBD based hybrid booster module. The conversion efficiency gain of 1.4 % is realizable by replacing the Si-based booster module with the Si IGBT/SiC SBD hybrid boost module in the 6.6 kW on-vehicle chargers.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.552-557
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• 2004

Effects of a booster inducer on the suction performance of turbopumps are investigated in this paper. To see the effect of the booster inducer, suction performance tests are conducted with and without the booster inducer for three turbopumps. It is shown that the booster inducer can enhance the suction performance of turbopumps when the tip clearance of the main inducers are relatively large. Numerical analysis are also carried out to see the effects of the booster inducer on the performance of the main inducer. The booster inducer is shown to increase the static pressure at the inlet of the main inducer and prevent growing of inlet back flows which are believed to have deleterious effects on the suction performance of the inducer.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.504-507
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• 1991

Modelling and simulation of booster which is used as step-up DC/DC converter for small scale fuel cell generator is studied. And 2kW booster based on this result is designed. Especially, booster efficiency related with fuel cell and control characteristics are analyzed and a 2kW booster is experimented in various operating condition. As a result, power conversion efficiency is above 74% throughout the whole operating range.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1314-1319
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• 2002

A mathematical model and control laws for an Electronic-Vacuum Booster (EVB) for application to vehicle cruise control will be presented. Also this paper includes performance test result of EVB and vehicle cruise control experiments. The pressure difference between the vacuum chamber and the apply chamber is controlled by a PWM-solenoid-valve. Since the pressure at the vacuum chamber is identical to that of the engine intake manifold, the output of the electronic-vacuum booster Is sensitive to engine speed. The performance characteristics of the electronic-vacuum booster have been investigated via computer simulations and vehicle tests. The mathematical model of the electronic-vacuum booster developed in this study and a two-state dynamic engine model have been used in the simulations. It has been shown by simulations and vehicle tests that the EVB-cruise control system can provide a vehicle with good distance control performance in both high speed and low speed stop and go driving situations.

• Clinical and Experimental Vaccine Research
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• v.12 no.2
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• pp.116-120
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• 2023

Purpose: In Japan, the data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers after the booster dose of the coronavirus disease 2019 (COVID-19) vaccine are insufficient. The aim of this study is to evaluate changes in SARS-CoV-2 antibody titers before, 1, 3, and 6 months after the booster dose of the BNT162b2 COVID-19 vaccine among health care workers. Materials and Methods: A total of 268 participants who received the booster dose of the BNT162b2 vaccine were analyzed. SARS-CoV-2 antibody titers were measured before (baseline) and at 1, 3, and 6 months after the booster dose. Factors associated with changes in SARS-CoV-2 antibody titers at 1, 3, and 6 months were analyzed. Cutoff values at baseline were calculated to prevent infection of the omicron variant of COVID-19. Results: The SARS-CoV-2 antibody titers at baseline, and 1, 3, and 6 months were 1,018.3 AU/mL, 21,396.5 AU/mL, 13,704.6 AU/mL, and 8,155.6 AU/mL, respectively. Factors associated with changes in SARS-CoV-2 antibody titers at 1 month were age and SARS-CoV-2 antibody titers at baseline, whereas changes in SARS-CoV-2 antibody titers at 3 and 6 months were associated with the SARS-CoV-2 antibody titers at 1 month. The cutoff values of the SARS-CoV-2 antibody titers at baseline were 515.4 AU/mL and 13,602.7 AU/mL at baseline and 1 month after the booster dose, respectively. Conclusion: This study showed that SARS-CoV-2 antibody titers increase rapidly at 1 month after the booster dose of the BNT162b2 vaccine and begin to decrease from 1 to 6 months. Hence, another booster may be needed as soon as possible to prevent infection.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.33-41
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• 2011

A mathematical model of slip-in booster separation dynamics is described. A longitudinal 3-DOF(degree of freedom) 2-body dynamic model is developed to simulate the separation dynamics. Aerodynamic models of the missile and the exposed area of booster are built. And, gas generator pushing the booster out and internal channel pressure drop are modelled. To simulate the model, it is assumed that the missile can maintain the 1g level-fight condition during the separation. With this assumption, the interaction forces between missile and booster through the separation phases: phase 0: initial, phase 1: linear translation, and phase 2: free flight motion are defined. Using the simulation, missile flight conditions for slip-in booster`s safe separation, which can be represented by Mach vs. height envelope, are suggested.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1038-1040
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• 1992

Booster is used widely as one of the step-up DC/DC power converter in power conversion process for fuel cell power plant which have the electrical characteristic of the high current density and low cell voltage. In view of control system, booster can be unstable when it is operated in broad operation range because the transfer function of booster has zero in right half plane of s-domain. So for reliable operation, controller must make the system stable in whole working range. In this paper, the two control method such as digital PID control and fuzzy control is studied for booster output voltage regulation in fuel cell plant. The design procedure of PID control and fuzzy control is described. And the experiment of designed controller action is performed in various operation points for controller performance test.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.6
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• pp.519-525
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• 2012

Electric brake booster systems replace conventional pneumatic brake boosters with electric motors and rotary-todisplacement mechanisms including ECU (Electronic Control Unit). Electric booster brake systems require precise target pressure tracking and control robustness because vehicle brake systems operate properly given the large range of loading and temperature, actuator saturation, load-dependent friction. Also for the implement of imbedded control system, the controller should be selected considering the limited memory size and the cycle time problem of real brake ECU. In this study, based on these requirements, a sliding mode controller has been chosen and applied considering both model uncertainty and external disturbance. A mathematical model for the electric booster is derived and simulated. The developed sliding mode controller considering chattering problem has been compared with a conventional cascade PID controller. The effectiveness of the controller is demonstrated in some braking cases.