• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.1
• /
• pp.60-67
• /
• 2006

To improve the vehicle fuel economy, various technologies have been studied. Meanwhile it deteriorates fuel economy that the increased driving torque for Power Steering System (PSS) due to weighted vehicle and widened tire for low speed driving and parking. So the larger driving torque for PSS is, the lower fuel economy is. Therefore, the study about the effect of the driving torque for PSS and the engine total friction must be preceded to improve the vehicle fuel economy. In this study, a PSS module separated from the vehicle is used to measure the driving torque for PSS with respect to the pressure of PSS. The result shows that the driving torque for PSS was in direct proportion to the pressure of PSS 3 (N-m) driving torque for PSS vs. 10 (bar) pressure of PSS, and 8 (N-m) vs. 40 (bar). In addition, the driving torque and pressure for PSS was measured according to the engine speed in the component test condition which was in the vehicle condition. Measuring the driving torque for PSP in the vehicle condition was established by using the VeFAS which was a fuel economy analyzer developed in our lab and installing PSS By-pass line. The effect of the driving torque for PSS on the vehicle fuel economy was analyzed with FTP-75 cold start mode.

• Journal of the Korea Convergence Society
• /
• v.11 no.5
• /
• pp.175-182
• /
• 2020

The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2769-2774
• /
• 2007

In vacuum ejector-diffuser systems where a finite volume secondary chamber is used, the secondary jet exhibits transient characteristics during start-up. A steady state is achieved after some time in which mass entrainment prevails indefinitely inside the ejector, though there is no flow from the secondary chamber. An attempt is made in this work to study the infinite entrainment of secondary jet into the primary jet from a finite secondary chamber, with the help of a computational fluid dynamics method. The present study is also intended to identify the operating range of vacuum ejector-diffuser systems where the steady flow assumption can be applied without uncertainty. The results obtained show that the only condition in which an infinite mass entrainment is possible is the generation of a re-circulation zone near the primary nozzle exit. The flow in the secondary chamber attains a state of dynamic equilibrium at this point. Steady flow assumption is valid only after this point.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.54 no.3
• /
• pp.117-121
• /
• 2005

Power system restoration following a massive blackout starts with re-energizing primary transmission lines at first. Some factors such as Ferranti effect, and line charging reactive power should be considered in this stage. Severe overvoltage may be induced by the Ferranti effect at the lines since it would be usually no load condition. And lack of capacitive reactive power will cause the self-excitation. This paper presents a new precise algorithm to analyze the primary restorative transmission system focused on the two major static overvoltage problems during the early restoration process.

• Journal of Haehwa Medicine
• /
• v.16 no.1
• /
• pp.191-197
• /
• 2007

Gak-gi-byung in Korean Medicine have many things in common with Beriberi disease, Guillain-Barre syndrome, Transverse myelitis and Cauda equina syndrome. Dong-Ui-Bo-Gam define Gak-gi-byung as syndrome that includes sudden lower limbs weakness, pain and edema. Gak-gi-byung start from the foregoing symptoms and could progress to general digestive, neurological or respiratory symptoms is found on many medical practitioners. In this case, we described a 60-years old man diagnosed as Gak-gi-byung in Korean Medicine. He complained Rt lower limb weakness, Rt Knee Clumsiness and limitation of his Rt knee & ankle motor. And his condition was improved through Korean Medical treatment such as acupuncture and herbal medicine like 'Chung-yul-sa-seup-tang' about 15 days.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.54 no.1
• /
• pp.73-80
• /
• 2018

Intermittent duty of emergency generator has problems emitting large quantities of PM and NOx in exhaust gas. The aim of this study is to propose DPF system which can be applied to medium-large emergency generators. The system is composed of soot dust collector, silencer and filter trap, which is designed to reduce PM emissions at the emergency generator start-up. The pneumatic system controls a flow direction of exhaust gas to pass through the soot collector and filter trap until the engine reaches complete combustion condition. An experiment is performed to measure PM content and concentration to analyze the performance and characteristics of the proposed system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.11a
• /
• pp.9-10
• /
• 2007

This paper presents that what's the right EOLL(End of Lamp Life) phenomenon on fluorescent lamp and how to detect it according to the lamp status. In normal end of life situation for fluorescent lamps is emitter depletion of the cathodes. So, in most cases, the discharge will extinguish and the lamp will not start. But if the ballast is capable of sustaining the discharge, a new condition arise. Especially, the T4 and T5 lamp which has a short distance from cathode to socket of lamp future must have the EOLL Protection function.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10b
• /
• pp.36-41
• /
• 1993

The adiabatic slirn-type autoclave reactor for free radical polymerization of LDPE is represented by a two-compartment four-cell model, which is proven effective to predict the reactor behavior as well as the polymer properties. Since the temperature distribution along the reactor axis plays the central role for the properties of the polymer product, it is important in practice to regulate the temperature in each compartment. The present study aims for the application of the adaptive control algorithm not only in the period of start-up but also during the steady state operation. It is shown that the temperature control is significantly improved over the conventional PID-control and this also brings about a reduction of variations in the polymer properties. This study demonstrates the potential application of the adaptive controller for the control of the polymerization reactor operated under the adiabatic condition.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.205-207
• /
• 2009

LCD (liquid crystal display) industry is needed to goods of high reliability and is interested in products without harmful material. In this experiment, we made the LED backlight unit for Automotive-navigation. And for making this backlight unit we used to eight side emitting type white LEDs with 1W high power of the lumileds company. We could know that this backlight unit releases to 6500 nit in 14W power consumption and start up voltage time is under the15ms in the ambient temperature -20 $^{\circ}C$.

• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.2
• /
• pp.44-53
• /
• 1992

Automotive transmission is the principle component of vehicle driving system, which transmits the adjusted engine power. The automation of transmission arises from the annoyance of transmission operation such as the frequent stop/start of vehicle and the shifting transients. The study on the optimal shifting condition for the automation of transmission needs the investigation of shifting transients. However, the dynamic modeling theory during transient period is not well-established. In this study, the techniques of dynamic modeling for the power transmission system with Merrite-Wilson gear train are presented. To predict the shifting transients, a driving simulation program is developed, and the results of the analysis are cross-checked in the field test.