So-Nam Yun

So-Nam Yun


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 January 2020 in Micromachines
Verified
Journal Article
Open access
PDF file
Mojiz Abbas TrimziMojiz Abbas Trimzi
Mojiz Abbas Trimzi
YHYoung Bog Ham
Young Bog Ham
BAByeung Cheol An
Byeung Cheol An
Young Min ChoiYoung Min Choi
Young Min Choi
JPJungho Park
Jungho Park
SYSo-Nam Yun
So-Nam Yun
Owing to the quick response, compact structure, high precision, huge blocking force generation, and ease of operation, piezoelectric actuators are urgently being adopted in the field of advanced dispensing for jetting performance improvement and fulfillment of precision requirements in microelectronics packaging, adhesive bonding, and miniaturization industry. This research focuses on the fundamental design and development of a piezo-electrically driven compact fluid dispenser using the principle of a class-one lever for amplification of needle displacement, and enhancement of application areas of the developed jet dispenser. Using fundamental lever principle, geometry-based modelling is carried out to fabricate a working prototype of a normally closed hinge-lever type dispenser. Preliminary experiments are carried out to witness the workability of the fabricated dispenser to deliver 100 dots of working fluid per second that will provide a novel device for dispensing of various fluids, and the proposed amplification mechanism suits various other piezoelectric applications as well.

1 December 2006 in Journal of Electroceramics
Verified
Journal Article
Closed access
PDF file
SYSo-Nam Yun
So-Nam Yun
YHYoung-Bog Ham
Young-Bog Ham
CKChan-Yong Kim
Chan-Yong Kim
JPJung-Ho Park
Jung-Ho Park

1 January 2006
Verified
Conference Paper
Closed access
SYSo-Nam Yun
So-Nam Yun
YHYoung Bog Ham
Young Bog Ham
JPJungho Park
Jungho Park
BRByung-Soon Ryu
Byung-Soon Ryu
BCByung-Oh Choi
Byung-Oh Choi
The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 1 pm, maximum operating pressure of 0.9 MPa and frequency characteristic of 10 Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9 MPa directly. In this study, bimorph type PZT actuator of 25.2 mm (L)times7.2 mm (W)times0.5 mm (H) with constant of -220 times10 -12 CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of 63 mum were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6 mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator

13 January 2016 in Journal of Mechanical Science and Technology
Verified
Journal Article
Closed access
PDF file
YTYoshito Tanaka
Yoshito Tanaka
SYSo-Nam Yun
So-Nam Yun
YTYutaka Tanaka
Yutaka Tanaka

6 July 2007 in Journal of Electroceramics
Verified
Journal Article
Closed access
PDF file
SYSo-Nam Yun
So-Nam Yun
YHYoung Bog Ham
Young Bog Ham
JPJungho Park
Jungho Park
HSH. J. So
H. J. So
ILI. Y. Lee
I. Y. Lee

10 September 2021 in Actuators
Verified
Journal Article
Open access
PDF file
HKHaroon Ahmad Khan
Haroon Ahmad Khan
SYSo-Nam Yun
So-Nam Yun
EJEun-A Jeong
Eun-A Jeong
JPJeong-Woo Park
Jeong-Woo Park
BCByung-Il Choi
Byung-Il Choi
Solenoid-actuated pressure-reducing valves are commonly used in hydraulic machinery. Most studies on solenoid-actuated pressure control devices are focused on the electrical input signals or on the control techniques for the solenoid valves, but no study has been done that determines the influence of the design parameters on the valve’s output. Before designing a controller, it is imperative to know the valve’s performance by determining the significance of each valve parameter. In this study, established physical laws from fluid dynamics and mechanics are used to build a model that is solved using the ODE 45 solver of Simulink in the time domain. The actuating force, up to 15 N, exerted on the spool and the inlet pressure, ranging from 50 to 80 bar, are obtained through experimentation. It is found that the output pressure fluctuates significantly if the outlet is blocked, while at the fully opened outlet condition, a flow rate of 12 (L/min) was obtained. A pin diameter of 2.15 mm enables us to vary the output pressure between 0 and 41 bar. We found that higher inlet pressure leads to lower output pressure as the outlet is opened. No linearization of the actual mathematical model is performed, which makes the study unique.