• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.11
• /
• pp.1421-1426
• /
• 2012

Cornering maneuvers with reduced body roll and without comfort loss are important requirements for car manufacturers. An electric active roll control(ARC) system controls the body roll angle by using motor-driven actuators installed at the centers of the front and rear stabilizer bars. Co-simulation using the Matlab/Simulink controller model and the CarSim vehicle model was proposed to evaluate the performance of the ARC control algorithm. To validate the performance of the ARC actuator and system, bench tests and vehicle tests were proposed.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.81.3-81.3
• /
• 2017

In this paper, we report a small-scale emerging island and double arc loops, which are associated with a M6.5 flare, in Active Region 12371. We investigate the spatial and temporal changes of both photospheric magnetic fields using SDO/HMI data and coronal magnetic structures obtained from nonliner force-free field (NLFFF) extrapolation. From the vector magnetograms, we find a small-scale emerging island near the main polarityy inversion line about three hours before the flare. The island has a strong shear angle, which is determined by difference between transverse component of observed field and potential field, of around 90 degrees. Furthermore, the NLFFF well reproduces a sigmoidal structure seen in SDO/AIA 94, which is consistent with the double arc loops configuration suggested by Ishiguro and Kusano (2017) who introduced a magnetic configuration showing the double arc instability. The observed emerging island is located among the double arc loops, which is also supproted by their model. Finally, there was an eruption (M6.5 flare) associated with the loops. We discuss a possible role of the double arc instability for the eruption.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.8
• /
• pp.828-834
• /
• 2014

This paper presents a comparison among three types of approaches to an ARC (Active Roll Control) with an AARB(Active Anti-Roll Bar) for a vehicle system. Lateral acceleration and road profile are considered as disturbance. The ARC is designed with an LQ SOF (Linear Quadratic Static Output Feedback) control, $H_{\infty}$ control and SMC (Sliding Mode Control). These approaches are compared in terms of rollover prevention and ride comfort. For comparison, Bode plot analysis based on linear model and frequency response analysis based on CarSim simulation are performed.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1345-1347
• /
• 2008

This paper described a method of determining whether arcing is present in a low-voltage wiring system. We simulated the series arcing that generated in electrical loads and fabricated a arc detection module which can discriminate between normal and arcing state. The module consists of a high-pass filter with a low cut-off frequency of 3 kHz to attenuate power frequency voltage and an active band-pass filter with a frequency of 4 kHz ${\sim}$ 8 kHz to detect series arc signals only. We tested an Incandescent lamp that was controlled by a dimmer and analysed. The module consists of a high-pass filter with a low cut-off frequency of 3 kHz to attenuate power frequency voltage by 80 dB and an active band-pass filter with a frequency of 4 kHz to detect series arc signals only. From the experimental results, we could detect series arc signals without an influence of non-linear loads.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1996.11a
• /
• pp.27-41
• /
• 1996

In this study the heat transfer and fluid flow of the molten pool in stationary gas tungsten arc welding using argon shielding gas were investigated. Transporting phenomena from the welding arc to the base material surface, such as current density, heat flux, arc pressure and shear stress acting on the weld pool surface, were taken from the simulation results of the corresponding welding arc. Various driving forces for the weld pool convection were considered, self-induced electromagnetic, surface tension, buoyancy, and impinging plasma arc forces. Furthermore, the effect of surface depression due to the arc pressure acting on the molten pool surface was considered. Because fusion boundary has a curved and unknown shape during welding, a boundary-fitted coordinate system was adopted to precisely describe the boundary for the momentum equation. The numerical model was applied to AISI 304 stainless steel and compared with the experimental results.

• Korean Journal of Microbiology
• /
• v.52 no.2
• /
• pp.192-201
• /
• 2016

Recently, Psychrobacter sp. ArcL13 strain showing the extracellular lipase activity was isolated from the Chuckchi Sea of the Arctic Ocean. However, due to the low expression levels of the enzyme in the natural strain, the production of recombinant lipase is crucial for various applications. Identification of the gene for the enzyme is prerequisite for the production of the recombinant protein. Therefore, in the present study, a novel lipase gene (ArcL13-Lip) was isolated from Psychrobacter sp. ArcL13 strain by gene prospecting using PCR, and its complete nucleotide sequence was determined. Sequence analysis showed that ArcL13-Lip has high amino acid sequence similarity to lipases from bacteria of some Psychrobacter genus (84-90%) despite low nucleotide sequence similarity. The lipase gene was cloned into the bacterial expression plasmid and expressed in E. coli. SDS-PAGE analysis of the cells showed that ArcL13-Lip was expressed as inclusion bodies with a molecular mass of about 35 kDa. Refolding was achieved by diluting the unfolded protein into refolding buffers containing various additives, and the highest refolding efficiency was seen in the glucose-containing buffer. Refolded ArcL13-Lip showed high hydrolytic activity toward p-nitrophenyl caprylate and p-nitrophenyl decanoate among different p-nitrophenyl esters. Recombinant ArcL13-Lip displayed maximal activity at $40^{\circ}C$ and pH 8.0 with p-nitrophenyl caprylate as a substrate. Activity assays performed at various temperatures showed that ArcL13-Lip is a cold-active lipase with about 40% and 73% of enzymatic activity at $10^{\circ}C$ and $20^{\circ}C$, respectively, compared to its maximal activity at $40^{\circ}C$.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.3
• /
• pp.193-200
• /
• 2004

The Active Constrained Layer Damping(ACLD) combines the simplicity and reliability of passive damping with the low weight and high efficiency of active control to attain high damping characteristics. The proposed ACLD treatment consists of a viscoelastic damping which is sandwiched between an active piezoelectric layer and a host structure. In this manner, the smart ACLD consists of a Passive Constrained Layer Damping(PCLD) which is augmented with an active control in response to the structural vibrations. The arc type shell model is introduced to describe the interactions between the vibrating host structure, piezoelectric actuator and viscoelastic damping. The system is modeled by applying ARMAX model and changing a state-space form through the system identification method. An optimum control law for the piezo actuator is obtain by LQR(Linear Quadratic Regulator) method. The performance of the ACLD system is determined and compared with PCLD in order to demonstrate the effectiveness of the ACLD treatment. Also, the actuation capability of a piezo actuator is examined experimentally by varying thickness of viscoelastic material(VEM).

• Journal of Power Electronics
• /
• v.6 no.3
• /
• pp.195-204
• /
• 2006

This paper presents a new compensating system, consisting of series and shunt active filters, for mitigating voltage and current disturbances. The shunt filter is used to compensate for unbalanced and distorted load currents. The series filter comprises two inverters, used to suppress voltage disturbances and handle source currents independently. This configuration is devised to reduce the overall cost of active compensators by using low-frequency high-current switches for the latter inverter. The filters are controlled separately using a novel control strategy. Since voltages at the point of common coupling contain interharmonics, conventional methods cannot be used for extracting voltage references. Therefore, voltage references are obtained from generated sinusoidal waveforms by a phase-locked loop. Current references are detected based on rotating frame vector mapping. Simulation results are presented to verify the system.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.316-320
• /
• 2008

This paper described the design and fabrication of a series arc detection module to monitor electrical insulation in low-voltage system. The module consists of a passive high-pass filter with a low cut-off frequency of 3 kHz to attenuate power frequency voltage by 80 dB and an active band-pass filter with a frequency of 4 kHz to detect series arc signals only. For the application experiment, we simulated series arcing phenomena on various loads such as incandescent lamp controlled by dimmer and inverter fed induction motors by an arc generator specified in UL1699. From the experimental results, we could detect series arc signals without an influence of noises.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.1032-1038
• /
• 2002

The Active Constrained Layer Damping(ACLO) combines the simplicity and reliability of passive damping with the low weight and high efficiency of active control to attain high damping characteristics. The proposed ACLD treatment consists of a viscoelastic damping which is sandwiched between an active piezoelectric layer and a host structure. In this manner, the smart ACLD consists of a Passive Constrained Layer Damping(PCLD) which is augmented with an active control in response to the structural vibrations. The Arc type shell model is introduced to describe the interactions between the vibrating host structure, piezoelectric actuator and visco damping, The system is modeled by applying ARMAX model and changing a state-space form through the system identification method. An optimum control law for piezo actuator is obtain by LQR(Linear Quadratic Regulator) Method. The performance of ACLD system is determined and compared with PCLD in order to demonstrate the effectiveness of the ACLD treatment, Also, the actuation capability of a piezo actuator is examined experimentally by using various thickness of Viscoelastic Materials(VEM).